Infection Control and Barrier Precautions

• A pathogen is a disease producing microorganism.
• Transmission is any mechanism by which a pathogen is spread by a source or reservoir to a host.
• Reservoir is any person, animal, plant, soil, substance, or any combination of these in which an infectious agent normally lives and multiplies. The infectious agent depends on the reservoir for survival, and the reservoir must provide a place where it can reproduce itself in such a manner that it can be transmitted to a susceptible host.
• Susceptibility is defined as the inability of a host to resist infection with a particular pathogen. 
• The common vehicle is a contaminated material, product, or substance that serves as an intermediate means by which an infectious agent is transported to two or more susceptible hosts.
• Colonization is when an organism is present without host interference or interaction, like normal skin flora. 
• Host: An organism in which another organism can live and potentially multiply. 
• Infection is when there are invasion and multiplication by a microorganism. Infection may be local or systemic; it may begin as local and become systemic, and; there may be no apparent host response or clinical signs and symptoms caused by the infection and/or the host response. 
• Infectious disease is when the infected host shows a decline in wellness due to an infection. 
• Incubation period is the time between the beginning of an infection and recognition of symptoms.  
• Latency is the time after primary infection during which the microorganism lives within the host without producing clinical evidence.
• Virulence is the degree of pathogenicity of a microorganism, i.e., how easily it can invade a host and the severity of the disease it can cause.

A chain of events is required for infection to occur. These events are a causative organism, a reservoir for the organism, a means to exit the reservoir, a mode of transmission, a susceptible host, and a mode of entry into the host. Causative organisms may be bacteria, rickettsiae, viruses, protozoa, fungi, or parasites. The characteristics of causative organisms are:

• Pathogenicity: The ability of a microorganism to cause disease.
• Virulence is the degree of pathogenicity of a microorganism, i.e., how easily it can invade a host and the severity of the disease it can cause.
• Invasiveness: The ability of a microorganism to enter into and move through tissue.
• Infectious dose: The number of organisms needed to initiate an infection.
• Organism specificity: Host preference of the infectious agent
• Antigen variations: The ability of an infectious organism to change its surface proteins in order to escape host defenses.
• Toxigenicity: The capacity to produce toxins
• Resistance: The ability to develop resistance to antimicrobial agents

The organism and its reservoir are the sources of infection. The organism must have a means to exit the reservoir. In an infected host, the organisms exit through the respiratory tract, gastrointestinal tract, genitourinary tract, or drainage from a wound. A route of transmission is necessary to connect the source of infection to its new host. Routes of transmission are contact or airborne.

• Direct contact: Person-to-person.
• Indirect contact: Usually contact with a harmless inanimate object. The infected inanimate object is called a fomite. Fomites can survive on objects and surfaces for a long time and be a potential source of infection for weeks and months, e.g., fomites containing norovirus and Clostridium difficile.
• Droplet contact: Large particles from coughing, sneezing, or talking. Droplets move through the air, but because of their size and the limited time they are airborne, they quickly settle on environmental surfaces and are spread by contact, e.g., influenza, not by inhalation.

• Droplet nuclei: Residue of evaporated droplets that remain suspended in the air. Pathogens spread by airborne transmission include Mycobacterium tuberculosis and Varicella.
• Dust: Particles in the air containing the infectious agents.

The following table outlines the organism, mode of transmission and incubation period for most common microorganisms and parasites.

The host must be susceptible to the infection for infection to occur. Factors influencing susceptibility are:

• Number of organisms to which host is exposed and the duration of exposure
• Age, genetic constitution of host, and general physical, mental, and emotional health and nutritional status of the host
• Status of hematopoietic systems; efficacy of reticuloendothelial system
• Absent or abnormal immunoglobulins
• The number of T lymphocytes and their ability to function

Pregnant healthcare professionals are not known to be at greater risk of contracting bloodborne infections; however, during pregnancy, the infant is at risk of perinatal transmission.

The organism must have a portal of entry into the host for infection to occur. Portals of entry are the mucous membranes, non-intact skin, respiratory tract, gastrointestinal tract, genitourinary tracts, or a mechanism of introduction (percutaneous injury or invasive devices).

Enterobacteriaceae are gram-negative bacilli that are commonly found in the gastrointestinal tract. Common species of this family that cause infections include Enterobacter, Escherichia coli, and Klebsiella. Carbapenem-resistant enterobacteriaceae (CRE) are resistant to treatment with the carbapenem family of antibiotics (Doripenem, ertapenem, imipenem, and meropenem), the antibiotics that have traditionally been used to treat pathogens that are resistant to broad-spectrum antimicrobials. The CRE is spread through contact with infected surfaces (e.g., hands or contaminated medical equipment), and infections with CRE are particularly dangerous: they can spread rapidly, the mortality rate can exceed 40%, and antibiotics that are effective against multi-drug resistant gram-negative bacilli are still being developed. CRE infections usually do not occur in healthy people; they are more likely to occur in hospitalized patients who have a compromised immune system, patients who are mechanically ventilated, or those who have received multiple antibiotics. The incidence of CRE infections is increasing. Control and prevention of CRE infections should focus on: 1) identifying colonized patients; 2) screening by taking stool, rectal, and perirectal cultures, and wound cultures when appropriate; 3) strict adherence to handwashing protocol; 4) environmental cleaning; 5) patient and staff cohorting; 6) staff education, and; 7) using contact precautions.^{67, 68}

Staphylococcus aureus is transmitted primarily via the hands of healthcare professionals and by direct contact with contaminated equipment and surfaces. Transmission is very efficient, and S aureus colonizes the skin and nares easily. Once colonized, the person faces the likelihood of infection when invasive procedures are performed.

Methicillin and oxacillin-resistant S aureus (MRSA, ORSA) are common causes of nosocomial infections in hospitals and extended care facilities. Methicillin- and oxacillin-resistant colonization are rarely recognized and MRSA colonization is quite common, so every patient must be assumed to have been exposed to and/or colonized with MRSA/ORSA. In addition, MRSA often contaminates medical equipment such as stethoscopes and environmental surfaces like computer keyboards. Methicillin- and oxacillin-resistant S aureus can produce toxins and invade body tissues. The only effective antibiotic for treating these infections is vancomycin. The Centers for Disease Control and Prevention (CDC) recommends strict adherence to Standard Precautions, correct and appropriate use of personal protective equipment PPE, appropriate handling of medical devices and laundry, and Contact Precautions should be used if the facility has decided that MRSA is of special clinical or epidemiological significance.⁶⁹

Vancomycin intermediate S aureus (VISA) and vancomycin-resistant S aureus (VRSA) are classified based on a lab test. The result of the test is called minimum inhibitory concentration (MIC), which is the measure of the minimum amount of antimicrobial agent that inhibits bacterial growth in a test tube. Staph bacteria are classified as VISA if the MIC for vancomycin is 4-8µg/ml, and classified as VRSA if the vancomycin MIC is >16µg/ml.⁷⁰ These infections must be reported to the CDC and the state department of health. Patients who are infected with VISA or VRSA should be in a single room; Contact Precautions and Standard Precautions are required; staff education is recommended; minimize the number of staff caring for the patient; and flag the chart to alert staff of the situation.⁷⁰

Enterococcus is a gram-positive bacterium that is normal flora of the gastrointestinal tract and female genital tract. It is a relatively weak pathogen, but it is capable of producing significant infections if the patient is infected with vancomycin-resistant enterococcus (VRE), treatment options for these infections are limited. People at risk for VRE infections include patients previously treated with vancomycin, patients in intensive care, patients who are immunocompromised, patients who have had abdominal or chest surgery, and patients with in-dwelling IV or urinary catheters.⁷¹ Vancomycin-resistant enterococcus is transmitted primarily via the hands of healthcare professionals and by direct contact with contaminated equipment and surfaces. There have been many approaches used to control VRE in healthcare settings, and the methods used should be tailored to the clinical setting, the specific patient/patients involved, and the epidemiological characteristics of the situation. Contact precautions and Standard precautions should be used to prevent transmission of VRE.^{71, 72}

Tuberculosis (TB) is caused by the Mycobacterium tuberculosis bacteria, and it is one of the oldest recognized infectious diseases. Multidrug-resistant tuberculosis is resistant to isoniazid, rifampin, the fluoroquinolones, and at least one of the three second-line injectable drugs used to treat TB. The incidence of MDR-TB has increased in recent years due to poor compliance with prescribed drug regimens, inappropriate/incorrect prescribing, patient risk factors, and characteristics of specific TB strains. Infection control measures should include separation of the infected patient/patients, using Standard Precautions, Respiratory Hygiene/Cough Etiquette, minimal hospitalization time, proper ventilation, and staff use of particulate respirators.^{73, 74} Airborne Precautions are required.⁷³

Streptococcus pneumoniae is a pathogen that is commonly found in the upper respiratory tract. Infections with this pathogen are a common cause of pneumonia, meningitis, sepsis, bacteremia, and otitis media ⁷⁵ and a leading cause of morbidity and mortality.⁷⁶ The elderly and the very young are the most susceptible. Transmission is from infected respiratory droplets, and it can be spread by coughing, sneezing, close contact, or contact with infected droplets. Penicillin-resistant and multidrug-resistant strains of this pathogen have begun to emerge and are widespread in some communities.^{75, 76} A vaccine for the most common serotypes of S pneumoniae is available but underutilized. Contact Precautions, Droplet Precautions, and Respiratory hygiene/Cough Etiquette should be used when caring for patients who are infected with this pathogen.⁷³ 

Acinetobacter is a bacterium that is usually found in the soil and water, and on the skin of healthy people. People who are susceptible to infections with drug-resistant Acinetobacter are usually immunocompromised and/or have chronic lung disease or diabetes. Outbreaks of pneumonia, urinary tract infections, wound infections, and blood infections from Acinetobacter occur in areas of healthcare facilities where very sick patients are cared for like intensive care units.^77-79 People on ventilators, patients who have prolonged hospital stays, patients who have had an invasive procedure (e.g., insertion of a central IV line) and patients who have open wounds are at greater risk.^77-79 The morbidity and mortality rates associated with drug-resistant Acinetobacter infections are very high, and outbreaks of these infections in healthcare facilities are very difficult to control.⁸⁰ Contact transmission is the primary way that Acinetobacter is spread, so Contact Precautions and Standard Precautions with special attention to hand washing are integral parts of controlling and preventing these infections. Because of the danger of these infections and the difficulty in containing outbreaks, patients who have an infection with drug-resistant Acinetobacter may need to be isolated, or their placement in the facility should be carefully considered.⁸¹

Standard Precautions are strategies for protecting healthcare professionals from occupational transmission of organisms; Standard Precautions also prevent patient-to-patient transmission and staff-to-patient transmission. Standard Precautions assume that all pre-existing patient infections cannot be identified. The primary underpinning of Standard Precautions is that all body fluids and secretions should be considered potentially infectious, and barrier precautions should be used routinely to protect from all sources of potential infection. Standard Precautions apply to nonintact skin and mucous membranes, blood, and all body fluids, secretions, and excretions, except sweat (And in certain circumstances sweat can be considered infectious). In some cases, e.g., with certain pathogens such as HIV, some body fluids such as vomit are only considered to be a risk for disease transmission if they contain visible blood. Additional precautions are based on highly transmissible or epidemiologically important pathogens. Transmission based precautions (isolation) are Airborne, Droplet, and Contact Precautions.

Standard Precautions has six basic elements: Hand washing, the use of personal protective equipment, safe and proper disposal of contaminated material and equipment, safe injection practices, Respiratory Hygiene/Cough Etiquette practices, and the use of masks for insertion of catheters or injections into spinal or epidural spaces via lumbar puncture. The new elements of Standard Precautions that have been added since they were formulated were designed to focus on patient protection. These elements are Respiratory Hygiene/Cough Etiquette, safe injection practices, and the use of masks for insertion of catheters or injections into spinal or epidural spaces via lumbar puncture.⁷³

Respiratory Hygiene/Cough Etiquette is a strategy to reduce transmission of respiratory infections at the first point of entry into a healthcare setting.

Image of sneezing/coughing boy-check source

Signs educating patients and families about Respiratory Hygiene/Cough Etiquette protocol should be posted at entry areas. The instructions are that persons with cough, congestion, rhinorrhea, or increased respiratory secretions should⁸⁴:

• Cover the mouth and nose when coughing or sneezing.
• Dispose of used tissues promptly
• Use a surgical mask if coughing and if tolerated
• Wash hands after contact with respiratory secretions
• Separate at least three feet from persons with respiratory infections in common areas when possible

The effectiveness of Cough Etiquette techniques has been questioned,⁸⁵ but it is still considered to be a mandatory part of infection control and its use among the lay public can be increased by education.⁸⁶

Healthcare personnel should observe Droplet Precautions (These will be discussed later in the module) when caring for patients who have signs and symptoms of a respiratory infection and for whom Respiratory Hygiene/Cough Etiquette is needed. Healthcare personnel who have a respiratory infection are advised to avoid direct patient contact, especially contact with high-risk patients. If this is not possible, then a mask should be worn while providing patient care.^{73, 84}

Needle stick and sharps injuries are a common occurrence in healthcare. The CDC estimates that 350,000 sharps injuries occur each year, and these injuries are a potential cause for transmission of, and infection with hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), and more than 20 other pathogens.⁸⁷ Infections with each of these pathogens are potentially life threatening but they are also preventable. Literature reviews and individual studies have shown that compared to other health care workers, nurses are especially at risk for needle stick injuries,^88-90 but housekeepers, physicians, laboratory staff, and other people who work in healthcare suffer these injuries, as well.⁹¹

BD SafetyGlide™ Shielding Hypodermic Needle

Hypodermic Needle-Pro® 18G - 25G

One serious bloodborne infection can cost more than a million dollars for medications, follow up laboratory testing, clinical evaluation, lost wages, and disability payments, and the human costs after an exposure are immeasurable. Employees who have been exposed to a dangerous pathogen such as HIV may experience anger, depression, fear, anxiety,^{92, 93} difficulty with sexual relations, difficulty sleeping, problems concentrating, and doubts regarding their career choice. The emotional effect can be long lasting, even after a low-risk exposure that does not result in infection.⁹⁴

Percutaneous injuries can be avoided by eliminating the unnecessary use of needles, using devices with safety features, and promoting education and safe work practices for handling needles and related systems. Since 1993, the use of safety-engineered sharps devices has increased while the use of conventional sharps devices has decreased. Vigorous efforts to prevent needle stick and sharps injuries (e.g., the Needle Stick Prevention and Safety Act of 2000) increased awareness of and use of safe injection practices, and improved equipment have helped to decrease the number of these injuries.^{91, 95}

A number of sources have identified the desirable characteristics of needle and sharp safety devices. These characteristics include the following⁹⁶:

• The device is needleless.
• The safety feature is an integral part of the device.
• The device preferably works passively, i.e., it requires no activation by the user. If user activation is necessary, the safety feature can be engaged with a single-handed technique and allows the professional's hands to remain behind the exposed sharp.
• The user can easily tell whether the safety feature is activated.
• The safety feature cannot be deactivated and remains protective through initial use to disposal.
• The device performs reliably.
• The device is easy to use and practical.
• The device is safe and effective for patient care.

Although each of these characteristics is desirable, some are not feasible, applicable, or available for certain healthcare situations. For example, needles will always be necessary where alternatives for skin penetration are not available. Also, a safety feature that requires activation by the user might be preferable to one that is passive in some cases. Each device must be considered on its own merit and ultimately on its ability to reduce workplace injuries. The desirable characteristics listed here should serve only as a guideline for device design and selection:

• Needles should NEVER be recapped, bent, broken, or removed from contaminated syringes. Recapping by hand is prohibited under the OSHA bloodborne pathogens standard [29 CFR 1910.1030] unless no alternative exists.
• Sharps should be disposed into a puncture-proof container that has a biohazard label and is designed specifically for sharps disposal.
• There is exposure to percutaneous injuries during procedures where there is opportunity for percutaneous exposure, particularly when there is poor visualization, blind suturing, the non-dominant hand opposing or next to a sharp, and exposure to bone spicules and metal fragments.
• Sharp equipment should be disassembled using forceps or other devices.
• Suturing should always be done with a needle holder, forceps, or other tool.
• Do not use fingers to hold tissue when suturing or cutting.
• Never leave sharps on a work field. If used needles or other sharps are left in the work area or are discarded in a sharps container that is not puncture resistant, a needle stick injury may result. Injury may occur when a healthcare professional attempts to transfer blood or other body fluids from a syringe to a specimen container (such as a vacuum tube) and misses the target.

Safe injection practice in hospitals is well established. However, needle stick and sharp injuries continue to occur, and occur frequently; they are often not reported, and; failure to use safe injection practices has led to several serious outbreaks of HBV and HCV infection.^97-101 Dolan et al. write:

“More than 50 outbreaks of viral and bacterial infections occurred in the United States during the period 1998-2014 because of these unsafe medical practices. These outbreaks resulted in the transmission of hepatitis B virus (HBV), hepatitis C virus (HCV), and bacterial pathogens to more than 700 patients. The unsafe practices used by HCP in these outbreaks can be categorized as syringe reuse between patients during parenteral medication administration to multiple patients, contamination of medication vials or intravenous (IV) bags after having been accessed with a used syringe and/or needle, failure to follow basic injection safety practices when preparing and administering parenteral medications to multiple patients, and inappropriate use and maintenance of finger stick devices and glucometer equipment used on multiple patients.¹⁰¹”

The following are examples of safe injection practices recommended by the CDC and other professional organizations. These apply to the use of needles, cannulas that replace needles and where applicable, intravenous delivery systems.^{82, 101, 102}

• Use aseptic technique to avoid contamination of sterile injection equipment.
  • Do not administer medications from a syringe to multiple patients, even if the needle or cannula on the syringe is changed.
  • Needles, cannula, and syringes are sterile, single-use items; they should not be reused for another patient nor to access a medication or solution that might be used for a subsequent patient.
• Use fluid infusion and administration sets (i.e., intravenous bags, tubing and connectors) for one patient only and dispose of them appropriately after use.
  • Consider a syringe or needle/cannula contaminated once it has been used to enter or connect to a patient's intravenous infusion bag or administration set.
  • Use needle-free systems when transferring solutions between containers.
• Use single-dose vials for parenteral medications whenever possible.
  • Do not administer medications from single-dose vials or ampules to multiple patients or combine leftover contents of single-dose vials for later use.
  • Always inspect vials prior to use and discard them if sterility has been compromised or if there is visible particulate matter, discoloration, etc.
• Remove syringes, needles and cannulas from their packaging immediately before use.
• If multi-dose vials must be used, both the needle or cannula and the syringe used to access the multi-dose vial must be sterile.
  • Do not keep multi-dose vials in the immediate patient treatment area and store them in accordance with the manufacturer's recommendations; discard them if sterility is compromised or questionable.
  • Always use a new, sterile needle to access a multi-dose vial.
  • Do not combine the contents of multi-use vials.
• Do not use bags or bottles of intravenous solution as a common source of supply for multiple patients.
• Infection control practices for special lumbar puncture procedures:
  • Wear a surgical mask when placing a catheter or injecting material into the spinal canal or subdural space, e.g., during myelograms, lumbar puncture, and spinal or epidural anesthesia.
• Employee safety
• Adhere to federal and state requirements for protection of healthcare personnel from exposure to bloodborne pathogens. Use PPE if there is or may be a risk for contact with blood or body fluids during an injection procedure.
• Hand hygiene should be performed prior to any use of injection equipment.
• Injection equipment should be stored and used in clean areas, and there should not be non-sterile contact with sterile devices.
• Disinfect catheter hubs and IV injection ports with alcohol or an approved disinfectant before inserting a needle. Use institutional policy for disinfecting catheter hubs and IV-line injection ports prior to accessing them with a needle.
• Always discard needles and sharps into the appropriate containers.

Handwashing is one of the most effective methods for preventing patient-to-patient, patient to staff, and staff-to-patient transmission of microorganisms, and it is one the foundations of infection control.^103-105

Hands should be washed, or alcohol-based rubs should be used: 1) before and after patient contact; 2) between patient contacts; 3) after gloves are removed; 4) after contact with blood, body fluids, secretions, mucous membranes, excretions, and contaminated equipment; 5) after contact with inanimate objects and medical equipment in the immediate vicinity of a patient; 6) after using the bathroom; 7) before eating; and 8) in certain situations, e.g., between tasks on the same patient to prevent cross contamination.¹⁰⁶

Improved adherence to hand hygiene, i.e. hand washing or use of alcohol-based hand rubs, has been shown to terminate outbreaks in healthcare facilities, to reduce transmission of antimicrobial resistant organisms (e.g. MRSA) and reduce overall infection rates.^{105, 107, 108}

However, despite unequivocal evidence of the effectiveness of hand hygiene and mandatory hand hygiene education, healthcare professionals’ compliance with hand hygiene protocols is often very low, at times < 30%.^{103, 109, 110} There are many reasons why healthcare professionals are non-compliant with hand hygiene protocols, such as perceived lack of time, perceived inconvenience, high work load, and poor staffing.^{103, 111} Interventions for improving compliance with hand hygiene protocol can increase compliance,^{112, 113} and both the CDC and the World Health Organization (WHO) have published advice and guidelines for improving hand hygiene compliance.^{114, 115} As part of these recommendations, the CDC is asking healthcare facilities to develop and implement a system for measuring improvements in adherence to hand hygiene recommendations. Some of the suggested performance indicators include periodic monitoring of hand hygiene adherence and providing feedback to personnel regarding their performance, monitoring the volume of alcohol-based hand rub used/1000 patient days, monitoring adherence to policies dealing with wearing artificial nails, and focused assessment of the adequacy of healthcare personnel hand hygiene when outbreaks of infection occur.

In addition to traditional handwashing with soap and water, the CDC recommends the use of alcohol-based hand cleansers by healthcare personnel who perform patient care because they address some of the obstacles that healthcare professionals face when taking care of patients and frequently washing their hands.¹⁰⁶ Alcohol-based hand rubs have been shown to be very effective, in most cases as effective as soap and water. They significantly reduce the number of microorganisms on skin, they are fast acting, and they cause less skin irritation than soap and water. When using an alcohol-based hand rub, apply the product to the palm of one hand and rub your hands together, covering all surfaces of the hands and fingers until the hands are dry, approximately 20 seconds.¹⁰⁶ Note that the volume needed to reduce the number of bacteria on hands varies by product and using the appropriate volume for each specific product is crucial for effectiveness.^{116, 117} Allergic contact dermatitis due to alcohol hand rubs is uncommon._¹¹⁸ However, with increasing use of such products by healthcare personnel, it is likely that true allergic reactions to these products will occasionally be encountered. Alcohol-based hand rubs take less time to use than traditional hand washing, 20 seconds versus 40-80 seconds.¹¹⁹ In addition hand rub dispensers can be mounted almost anywhere, unlike a sink and a water tap.

Soap and water (not an alcohol-based hand rub) should be used when: 1) hands are visibly dirty/soiled; 2) after known exposure to C. difficile if the endemic rates are high or the healthcare facility is experiencing an outbreak; 3) after known or suspected exposure to patients with infectious diarrhea during norovirus outbreaks; 4) if exposure to Bacillus anthracis is suspected or proven, and; after using the bathroom and before eating.¹⁰⁶ For all other situations, an alcohol-based hand rub can be used.

The use of hand hygiene does not eliminate the need for gloves. Gloves can significantly reduce hand contamination, prevent cross contamination, and protect patients and healthcare personnel from infection.120 However, improper use of gloves can greatly increase hand contamination.¹²¹ Gloves must be removed after patient contact and a new pair put on for each new patient contact, and they should be replaced if they are torn, damaged, or grossly soiled.

Healthcare personnel should avoid wearing artificial nails and keep natural nails less than one-quarter of an inch long if they care for patients at high-risk of acquiring infections, e.g., patients in intensive care units or transplant units.

When evaluating hand hygiene products for potential use in healthcare facilities, administrators or product selection committees should consider the relative efficacy of antiseptic agents against various pathogens and the acceptability of hand hygiene products by personnel. Characteristics of a product that can affect acceptance and therefore usage include its smell, consistency, color, and the drying effect on hands.

Handwashing with soap and water remains a sensible strategy for hand hygiene in non-healthcare settings and its use in these situations is recommended by the CDC and other experts.

Respiratory Hygiene/Cough Etiquette should be used when a patient, staff, or visitors have signs/symptoms of a respiratory infection. This infection control technique includes: 1) covering the nose and mouth when coughing or sneezing; 2) using tissues to contain respiratory secretions and properly disposing of them; 3) washing hand after using a tissue; 4) offering a surgical mask to anyone who is coughing; and 5) turning the head and maintaining at least 3 feet of separation when coughing.⁷³

Personal protective equipment (PPE) provides a physical barrier between the patient and the healthcare professional. Personal protective equipment includes face shields, gloves, goggles, gowns, hair covers, masks, respirators, and shoe covers. The appropriate use of PPE is an important element of Standard Precautions. The choice of what PPE to use and when to use it depends on the patient-provider interaction and the mode of transmission, e.g., blood-borne, airborne.⁷³ In most circumstances this decision is based on the professional judgment of the healthcare personnel.

Face shields, gowns, goggles, hair covers, masks, and shoe covers should be used if there is a risk for splash contact from blood or other potentially infectious body fluids/secretions to the eyes, mouth, mucous membranes, nose, or skin. Masks and respirators are used in certain situations to protect healthcare personnel, patients, and the public.

Gloves should be used: 1) if contact is anticipated (or is possible) with blood, other potentially infectious body fluids/secretions, or mucous membranes; 2) if there will be skin contact with patients who have, or may have skin colonization with certain pathogens such as MRSA;and 3) if there will be contact with contaminated or potentially contaminated medical equipment or environmental surfaces.⁷³ Double gloving is often used during surgical procedures, but there is no information about the protective effectiveness of this technique during routine patient care, and in those situations, single gloving is generally considered to be adequate.⁷³ Latex, nitrile, and vinyl gloves are available. Studies have shown that vinyl gloves are more likely to fail during patient care situations,⁷³ and latex gloves are superior in terms of bacterial passage if the glove is perforated.¹²²

Proper use of gloves^{73, 123}:

• Change gloves when moving from patient to patient
• Never wash or reuse gloves; they are single-use items
• Change gloves when the integrity of the glove has been compromised or if they are heavily soiled
• Change gloves after touching potentially contaminated medical equipment or environmental surfaces
• Handwashing should always be done after removing gloves. Gloves do not replace the need for handwashing as the gloves may have a small, unnoticeable defect, they may become torn during use, and hands can become contaminated when the gloves are removed.

Masks - often called surgical masks - are single use items. Surgical masks can protect healthcare workers, their use is part of Standard Precautions, Droplet Precautions, and Respiratory Hygiene/Cough Etiquette (The last two will be explained later),⁷³ and their use and the conditions for which they should be used are mandated by the Occupational Health and Safety Administration (OSHA).¹²³ Masks should be used^{73, 123}:

• To protect healthcare personnel from direct contact with blood, body fluids, and respiratory secretions.
• When performing a procedure that requires sterile technique in order to protect the patient from exposure to infectious agents in the mouth or nose of the person/persons performing the procedure, and if a patient is coughing, to limit the spread of droplets.
• It is often recommended that if the situation requires the use of a mask then goggles, a face mask or another type of eye and face protection should be used, as well.

Paper masks are not interchangeable with respirators, and they have limits.^{124, 125} They are primarily intended to protect the patient and the public (in the situations described above) and to protect healthcare workers from direct contact with infectious pathogens.^{73, 123-126} Respirators (Discussed in the following section of the module) are used to prevent the airborne transmission of selected and specific pathogens such as M. tuberculosis.⁷³

Standard Precautions and the OSHA Blood-borne pathogen standard dictate that face shields, goggles, or other types of eye and face protection should be used if there is a risk for eye, mucous membrane, or skin contact with blood or potentially infectious body fluids/secretions.^{73, 123} These devices have been shown to protect healthcare workers against the transmission of infectious pathogens.⁷³ The choice of which type of protection to use, e.g., goggles versus face shield, is determined by the clinical situation; there are no direct comparisons of one type of eye/face protective device with others.¹²⁷ Studies of their effectiveness in preventing pathogens contacting the users have produced mixed results,¹²⁸ and they should never be used as a substitute for respiratory protection devices.¹²⁹ Personal eyeglasses and contact lenses are not considered as adequate protective equipment and should not be used as a substitute for face shields, goggles, etc.⁷³

Gowns are worn to prevent contamination of clothing and protect the healthcare professional’s skin from blood and body fluid exposure. Impermeable gowns, leg coverings, boots, or shoe covers provide additional protection when large quantities of blood or body fluids may be splashed. The use of isolation gowns are part of Standard Precautions and Transmission Precautions, and their use is mandated by the OSHA Bloodborne Pathogens standard.^{73, 123} Isolation gowns are intended “ to protect the HCW’s arms and exposed body areas and prevent contamination of clothing with blood, body fluids, and other potentially infectious material.⁷³” Isolation gowns (sometimes referred to as surgical gowns, procedures gowns, or protective gowns) are disposable, single-use items made of materials that prevent movement of blood and other potentially infectious body/fluids/secretions through the gown and onto the user’s skin.¹³⁰

There are several types of gowns that offer differing levels of performance¹³¹; for example, a Level 1 gown is for minimal risk situations such as basic patient care, standard isolations precautions and a Level 3 gown is for moderate risk situations such as inserting an IV catheter while working in the ER.¹³¹ Isolation gowns should provide full coverage of the arms, the front of the torso, and from the neck to the middle of the thighs, and they should always be used with gloves and with other PPE, if needed.⁷³ Evidence for the effectiveness of gowns for preventing transmission of infectious material has been described as mixed.¹³² Laboratory jackets or coats are not an acceptable substitute for an isolation gown.⁷³

The proper sequence for putting on PPE is:

1. Wash hands
2. Gown
3. Mask or respirator
4. Goggles/face shield.
5. Gloves

The proper sequence for removing PPE is:

1. Gloves
2. Goggles/face shield
3. Gown
4. Mask
5. Wash hands

When removing PPE, it is important only to touch areas of the PPE that are not contaminated or potentially contaminated, e.g., the front of the gown would be considered to be potentially contaminated, the ties in the back of the gown would not.

Transmission Precautions and protective environment (PE) are terms used to describe protective measures that need to be employed for specific groups of patients. These measures address the three conditions needed for transmission of an infectious pathogen: a source, a susceptible host, and a method of transmission. An older term for Transmission Precautions was isolation. Patients requiring Transmission Precautions require a private room and a negative pressure air handling system that exhausts to the outside is required for Airborne Precautions. Movement of these patients should be limited, and when transport outside the room is necessary, appropriate barriers should be used. Masks should be used for patients who are on Airborne Precautions. Patients infected with the same organism can share a room; this is called cohorting.

Airborne Precautions are implemented for diseases that are transmitted by microorganisms carried by airborne droplet nuclei. Droplet nuclei are tiny particle residues left when droplets evaporate, and droplet nuclei remain suspended in the air, travel comparatively long distances, and can be widely dispersed by air currents. Airborne Precautions are needed if the infectious pathogen is < 5 microns; the infectious particles are found in aerosol form, and; the infectious particles travel a specific distance and remain airborne for a time that places those exposed at risk.¹³³ Early identification and triage of suspected cases of airborne transmitted diseases should be done, and possibly infectious patients should be separated from others and asked to wear a surgical mask. Most respiratory illnesses are spread by droplets, not aerosols, and the specific diseases that require Airborne Precautions are listed below.⁷³

Respirators are required to be worn by healthcare personnel if Airborne Precautions are in place or during certain procedures such as endotracheal intubation in which aerosols are formed.⁷³ In some high-risk situations, a powered air purifying respirator (PAPR) may be needed.

A surgical N95 respirator is recommended if Airborne Precautions are required.73 These respirators will block at least 95% of infectious particles 3 microns or larger in size.¹³⁴ The N95 is a single user, disposable item that must be fit tested to be effective. Fit testing should be done when first using an N95, and after the correct size and model have been chosen, the user should perform a user seal check each time the N95 is used.^{73, 134}

The N95 respirator is a disposable device (it cannot be cleaned or disinfected), but the N95 is different than a simple surgical mask that is discarded after one use as the N95 can be used more than once. There are guidelines for what has been termed extended use and reuse of the N95.¹³⁵ These are somewhat lengthy and complex and the reader can view them on the CDC website by using the link provided below. Fortunately, most healthcare providers do not need to be highly familiar with these guidelines or memorize them; the infection control department of each healthcare facility will, if needed, provide case-by-case instructions for N95 basic use, extended use, and reuse.

Airborne Precautions also require the use of an airborne infection isolation room (AIIR) that has specially engineered airflow and ventilation systems, e.g., a specially ventilated room with at least 12 air changes per hour; negative air pressure relative to the hallway; and outside exhaust or HEPA-filtered recirculation. The door to the room must be kept closed, and the negative air pressure should be monitored.

When the patient in airborne precautions has to be moved or transported, the patient should wear a surgical mask from the time he/she leaves the isolation room until she/he returns.

Droplet Precautions are used for patients known or suspected to be infected with microorganisms transmitted by droplets generated during coughing, sneezing, talking, or performance of procedures, e.g., the influenza virus. These droplets are larger than the aerosolized infectious particles that require the use of Airborne Precautions,¹³⁶ and they do not travel as far, usually 6 feet or less.¹³⁷ The diseases that require the use of Droplet Precautions are listed below.⁷³

Droplet Precautions require a private room, but no special ventilation is necessary, and the door may remain open. Masks should be worn if working within three feet of the patient. The patient should be masked if transported, and she/he should observe Respiratory Hygiene/Cough Etiquette.

Contact Precautions are used for patients with known or suspected infections, or colonized with epidemiologically important microorganisms that can be transmitted by direct or indirect contact.

Disease requiring the use of Contact Precaution are listed below.⁷³

If Contact Precautions are indicated, the patient should be in a private room. Standard Precautions should be used, and a gown and gloves should be worn if there is likely to be contact with the patient or environmental surfaces.

Some facilities may implement special isolation for VRE. This is an exaggerated form of contact precautions requiring the use of gowns and gloves anytime the room is entered, even if you do not anticipate patient contact.^{138, 139} The rationale is that VRE survives in the environment for a long time and contact with any surface may lead to transmission.

Neutropenic precautions (also called protective isolation or reverse isolation) are implemented to protect immunocompromised patients. Guidelines for neutropenic precautions have been published.¹⁴⁰ However, these are specific for certain clinical situations, and there is no standard universally accepted protocol that dictates how, when, and for whom neutropenic precautions should be used.^{141, 142} There are conditions and treatments, e.g., hematopoietic stem cell transplant, patients receiving chemotherapy, patients who have suffered a serious burn (A more detailed list is provided below), in which a patient is particularly at risk for infection. In these cases, special precautions should be taken, and in their 2007 Guideline for Isolation Precautions, the CDC does mention the need for, and use of a PE for immunocompromised patients. Some of the conditions of the PE include a private, well-sealed room with positive air pressure, HEPA filtered air, frequent air changes, and minimizing the amount of time the patient is outside the room.¹²³ The exact methods used for neutropenic precautions vary depending on the reason for the precautions and the degree of the patient’s immunosuppression and level of risk.

Conditions/Diseases that may require neutropenic precautions:

• Acquired immunodeficiency syndrome
• Agranulocytosis
• Burns
• Chemotherapy
• Hematopoietic stem cell transplantation
• Immunosuppressive therapy

Immunization is one method to reduce the transmission of communicable diseases. The following are recommendations for immunization based on age and exposure risk. Specifics and schedules for high- risk populations and catch-up immunizations are available from the CDC.

Immunization schedules for adults are available from the CDC.

Recommended immunization schedule for children and adolescents aged 18 years or younger, United States 2017

Immunization Chart

These recommendations for the immunization of healthcare personnel are from the Advisory Committee on Immunization Practices and the CDC.¹⁴³

Hepatitis B - Three doses of hepatitis B vaccine, the second given 1 month after the first, the third at approximately 5 months after the second.

Influenza - Two influenza vaccines are available, live attenuated influenza vaccine (LAIV) which is given intranasally and trivalent inactivated influenza vaccine (TIV), which is given as an intramuscular injection. Live attenuated influenza vaccine is licensed for use in healthy nonpregnant persons aged 2--49 years. The TIV can be given to anyone ≥6 months of age. Live attenuated influenza vaccine can be used for healthcare personnel except anyone who is caring for patients who are severely immunocompromised and require a PE. If the healthcare worker has a pre-existing condition that confers high risk for influenza complications, is pregnant, or is ≥50 years of age, that person should not receive LAIV; use TIV.

Meningococcal – A 2-dose meningococcal vaccine series is recommended for: 1) healthcare personnel who have asplenia or persistent complement component deficiencies; 2) healthcare personnel traveling to countries in which meningococcal disease is hyperendemic or epidemic and who have asplenia or persistent complement component deficiencies; these people should receive a 2-dose vaccine series. Other healthcare personnel traveling to high-risk area should be given a single dose of meningococcal conjugate vaccine quadrivalent (MCV4) before travel if they have never received it or if they received it >5 years previously. Clinical microbiologists and research microbiologists who might be exposed routinely to isolates of N. meningitides should receive a single dose of MCV4 and receive a booster dose every 5 years if they remain at increased risk. Health-care personnel aged >55 years who have any of the above risk factors for meningococcal disease should be vaccinated with MPSV4, i.e., meningococcal quadrivalent polysaccharide vaccine.

MMR – Vaccination with mumps, measles and rubella (MMR) vaccine, two doses, 4 weeks apart if the healthcare worker was born later than 1957 or if there is no serologic evidence of immunity.

Poliomyelitis - Vaccination against poliovirus is recommended for healthcare personnel who have a high risk of exposure, laboratory personnel who work with the virus, clinicians who have close contact with patients who might be excreting wild polioviruses, and healthcare personnel who are traveling to an area where the virus is endemic. Unvaccinated individuals should be given 3 doses of polio vaccine, dose 2 to be given 4-8 weeks after the first, dose 3 at 6-12 months after the second dose. Previously vaccinated individuals can receive a booster dose.

Tetanus, diphtheria, pertussis – Tdap once if never vaccinated, and a Td booster every 10 years.

Typhoid - Microbiologists and anyone who frequently works with S typhi should be vaccinated and booster vaccinations given as indicated.

Varicella – Healthcare personnel who have no evidence of immunity to varicella should be given 2 doses of varicella vaccine, 4-8 weeks apart.

• Contamination is the presence of microorganisms on inanimate objects or substances 
• Decontamination is the process of removing disease-producing microorganisms and rendering the object safe for handling
• Cleaning is the removal of visible blood, soil, and other debris, usually by soap and water or an enzyme cleaner and water
• Disinfection is the process that results in the elimination of many or all pathogenic microorganisms on inanimate objects with the exception of bacterial endospores
• High-level disinfection kills bacteria, mycobacteria (TB), fungi, viruses, and some bacterial spores
• Intermediate level disinfection kills bacteria, mycobacteria, most fungi, and most viruses. It does not kill resistant bacterial spores
• Low-level disinfection kills most bacteria, some fungi, and some viruses. It will not kill bacterial spores and is less active against some gram-negative rods like Pseudomonas and mycobacteria
• Sterilization is a process that completely eliminates or destroys all forms of microbial life

Basic education has been briefly discussed in previous sections of the module, and its application to other parts of the infection control process will be covered below. Both the CDC and OSHA recommend that the healthcare facility/employer must inform the staff of potential risks for exposure to infectious materials and provide them with the education and equipment they need to prevent contamination of medical equipment and the environment; to protect themselves against contamination and infection; and to protect patients against contamination and infections.

Cleaning, disinfection, and sterilization are essential for infection control and maintaining a safe environment. These processes can be used singly or in combination, they are done using different tools and techniques, and they produce different results. In simple terms, sterilization is intended to kill all microorganisms, disinfection will kill/remove the majority of microorganisms, and cleaning will physically remove surface contamination and debris.

General Principles of Cleaning, Disinfection, and Sterilization¹⁴⁵

• In general, reusable medical devices or patient-care equipment that enters normally sterile tissue or the vascular system or through which blood flows are considered to be critical items, and they should be sterilized before each use. Sterilization means the use of a physical or chemical procedure to destroy all microbial life, including highly resistant bacterial endospores. The major sterilizing agents used in hospitals are a) moist heat by steam autoclaving, b) ethylene oxide gas, and c) dry heat. However, there are a variety of chemical germicides (sterilants) that have been used for purposes of reprocessing reusable heat-sensitive medical devices and appear to be effective when used appropriately, e.g., according to manufacturer's instructions. These chemicals are rarely used for sterilization, but appear to be effective for high-level disinfection of medical devices that come into contact with mucous membranes during use (e.g., flexible fiberoptic endoscopes).
• Heat stable, reusable medical devices that enter the blood stream or enter normally sterile tissue should always be reprocessed using heat-based methods of sterilization (e.g., steam autoclave or dry heat oven).
• Laparoscopic or arthroscopic telescopes (optic portions of the endoscopic set) should be subjected to a sterilization procedure before each use; if this is not feasible, they should receive high-level disinfection. Heat stable accessories to the endoscopic set like trocars and operative instruments should be sterilized by heat-based methods (e.g., steam autoclave or dry heat oven).
• Reusable devices or items that touch mucous membranes should, at a minimum, receive high-level disinfection between patients. These devices include reusable flexible endoscopes, endotracheal tubes, anesthesia breathing circuits, and respiratory therapy equipment.
• Medical devices that require sterilization or disinfection must be thoroughly cleaned to reduce organic material or bioburden before being exposed to the germicide, and the germicide and the device manufacturer's instructions should be closely followed.
• Except on rare and special instances, items that do not ordinarily touch the patient or touch only intact skin are not involved in disease transmission and generally do not necessitate disinfection between uses on different patients. These items include crutches, bed-boards, blood pressure cuffs, and a variety of other medical accessories. Consequently, depending on the particular piece of equipment or item, washing with a detergent or using a low-level disinfectant may be sufficient when decontamination is needed. If noncritical items are grossly soiled with blood or other body fluids, a higher level of disinfections is required.

Cleaning and Disinfecting

Cleaning is the process of removing visible contamination and surface contamination from an object and can be completed mechanically or with cleaners. Cleaning can also help disinfect but the two processes are not the same, and cleaning is not intended to kill bacteria or other microorganisms. Disinfection is the process of destroying pathogenic organisms; disinfection cannot and does not destroy all organisms.

The following information is from the CDC Guideline for Sterilization and Disinfection in Healthcare facilities.¹⁴⁵

• Remove visible organic residue (e.g., residue of blood and tissue) and inorganic salts with cleaning. Use cleaning agents that are capable of removing visible organic and inorganic residues.
• Clean medical devices as soon as practical after use (e.g., at the point of use) because soiled materials become dried onto the instruments. Dried or baked materials on the instrument make the removal process more difficult and the disinfection or sterilization process less effective or ineffective.
• Perform either manual cleaning (i.e., using friction) or mechanical cleaning (e.g., with ultrasonic cleaners, washer-disinfector, washer-sterilizers).
• If using an automatic washer/disinfector, ensure that the unit is used in accordance with the manufacturer’s recommendations.
• Detergents or enzymatic cleaners should be compatible with the metals and other materials used in medical instruments.
• Ensure that the rinse step is adequate for removing cleaning residues to levels that will not interfere with subsequent disinfection/sterilization processes.
• Discard or repair equipment that no longer functions as intended or cannot be properly cleaned, and disinfected or sterilized.
• The rinse step should be adequate for removing cleaning residues to levels that will not interfere with subsequent disinfection/sterilization processes.
• Inspect equipment surfaces for breaks in integrity that would interfere with cleaning or disinfection/sterilization.
• Meticulously clean patient-care items with water and detergent, or with water and enzymatic cleaners before high-level disinfection or sterilization procedures.

Cleaning and Disinfecting Environmental Surfaces in Healthcare Facilities¹⁴⁵

• Cleaning and disinfecting environmental surfaces and patient rooms have been shown to decrease the incidence of hospital-acquired infections and to reduce environmental contamination with potentially dangerous microorganisms such as C difficile, MRSA, and VRE.¹⁴⁶
• Clean housekeeping surfaces (e.g., floors, tabletops) on a regular basis, when spills occur, and when these surfaces are visibly soiled.
• Disinfect or clean environmental surfaces on a regular basis (e.g., daily, three times per week) and when surfaces are visibly soiled.
• Follow manufacturers’ instructions for proper use of disinfecting or detergent products, such as recommended use-dilution, material compatibility, storage, shelf-life, and safe use and disposal.
• Clean walls, blinds, and window curtains in patient-care areas when these surfaces are visibly contaminated or soiled.
• Prepare disinfecting or detergent solutions as needed and replace these with fresh solution frequently, (e.g., replace floor mopping solution every three patient rooms, and change no less often than at 60-minute intervals or according to the facility’s policy).
• Decontaminate mop heads and cleaning cloths regularly to prevent contamination.
• Use a one-step process and an EPA-registered hospital disinfectant designed for housekeeping purposes in patient care areas where 1) uncertainty exists about the nature of the soil on the surfaces (e.g., blood or body fluid contamination versus routine dust or dirt), or 2) uncertainty exists about the presence of multidrug resistant organisms on such surfaces.
• Detergent and water are adequate for cleaning surfaces in non-patient care areas.
• Do not use high-level disinfectants/liquid chemical sterilants for disinfection of non-critical surfaces.
• Wet-dust horizontal surfaces regularly, e.g., daily, three times per week, using clean cloths moistened with an EPA-registered hospital disinfectant or detergent. Use the disinfectant or detergent as per the manufacturer’s recommendations.
• Disinfect noncritical surfaces with an EPA-registered hospital disinfectant according to the label’s safety precautions and use directions. Most EPA-registered hospital disinfectants have a label contact time of 10 minutes. However, many scientific studies have demonstrated the efficacy of hospital disinfectants against pathogens with a contact time of at least 1 minute.
• By law, the user must follow all applicable label instructions on EPA-registered products. If the user selects exposure conditions that differ from those on the EPA-registered product label, the user assumes liability for any injuries resulting from off-label use and is potentially subject to enforcement action.
• Do not use disinfectants to clean infant bassinets and incubators while these items are occupied. If disinfectants are used for the terminal cleaning of infant bassinets and incubators, thoroughly rinse the surfaces of these items with water and dry them before these items are reused.
• Promptly clean and decontaminate spills of blood and other potentially infectious materials. Discard blood-contaminated items in compliance with federal regulations.
• For site decontamination of spills of blood or other potentially infectious materials (OPIM), implement the following procedures. Use protective gloves and other PPE when sharps are involved. Use forceps to pick up sharps, and discard these items in a puncture-resistant container appropriate for this task.
• Disinfect areas contaminated with blood spills using an EPA-registered tuberculocidal agent, a registered germicide on the EPA Lists D and E, i.e., products with specific label claims for HIV or HBV or freshly diluted hypochlorite solution.
• If sodium hypochlorite solutions are selected use a 1:100 dilution (e.g., 1:100 dilution of a 5.25-6.15% sodium hypochlorite provides 525-615 ppm available chlorine) to decontaminate nonporous surfaces after a small spill (e.g., <10 mL) of either blood or OPIM.
• If a spill involves large amounts (e.g., >10 mL) of blood or OPIM, or involves a culture spill in the laboratory, use a 1:10 dilution for the first application of hypochlorite solution before cleaning in order to reduce the risk of infection during the cleaning process in the event of a sharp injury.¹⁴⁵
• Follow this decontamination process with a terminal disinfection, using a 1:100 dilution of sodium hypochlorite.
• If the spill contains large amounts of blood or body fluids, clean the visible matter with disposable absorbent material and discard the contaminated materials in appropriate, labeled containment.
• Use gloves and PPE that are appropriate for the task.
• In units with high rates of endemic Clostridium difficile infection or in an outbreak setting, use dilute solutions of 5.25%–6.15% sodium hypochlorite for routine environmental disinfection.^{145, 147} Currently, no products are EPA-registered specifically for inactivating C. difficile spores.
• If chlorine solution is not prepared fresh daily, it can be stored at room temperature for up to 30 days in a capped, opaque plastic bottle with a 50% reduction in chlorine concentration after 30 days of storage (e.g., 1000 ppm chlorine [approximately a 1:50 dilution] at day 0 decreases to 500 ppm chlorine by day 30).
• An EPA-registered sodium hypochlorite product is preferred, but if such products are not available, generic versions of sodium hypochlorite solutions (e.g., household chlorine bleach) can be used.

Indications for Sterilization, High-Level Disinfection, and Low-Level Disinfection

Before use on each patient, sterilize critical medical and surgical devices and instruments that enter normally sterile tissue or the vascular system or through which a sterile body fluid flows (e.g., blood).¹⁴⁶ Provide, at a minimum, high-level disinfection for semi-critical patient-care equipment (e.g., gastrointestinal endoscopes, endotracheal tubes, anesthesia breathing circuits, and respiratory therapy equipment) that touches either mucous membranes or nonintact skin.^{145, 146}
Perform low-level disinfection for noncritical patient-care surfaces (e.g., bedrails, over-the-bed table) and equipment (e.g., blood pressure cuff) that touch intact skin.¹⁴⁶

Selection and Use of Low-Level Disinfectants for Non-critical Patient-Care Devices ¹⁴⁵

• Intact skin is an effective barrier against most microorganisms. Because non-critical patient care devices like a sphygmomanometer cuff will only contact intact skin, these items do not need to be sterilized or extensively disinfected.¹⁴⁶ There is no documentation of infectious disease transmission from a non-critical patient care device/patient care equipment.¹⁴⁶ However, these devices and equipment can contaminate the hands of healthcare personnel and subsequently cause person-to-person contamination so cleaning these items is important.
• Process non-critical patient-care devices using a disinfectant and the concentration of germicide
• Disinfect non-critical medical devices (e.g., blood pressure cuff) with an EPA-registered hospital disinfectant using the label’s safety precautions and use directions. Most EPA-registered hospital disinfectants have a label contact time of 10 minutes. However, multiple scientific studies have demonstrated the efficacy of hospital disinfectants against pathogens with a contact time of at least 1 minute. By law, all applicable label instructions on EPA-registered products must be followed. If the user selects exposure conditions that differ from those on the EPA-registered product label, the user assumes liability from any injuries resulting from off-label use and is potentially subject to enforcement action.
• Ensure that, at a minimum, noncritical patient-care devices are disinfected when visibly soiled and on a regular basis (such as after use on each patient or once daily or once weekly).
• If dedicated, disposable devices are not available, disinfect noncritical patient-care equipment after using it on a patient who is on contact precautions before using this equipment on another patient.

Disinfectant Fogging

Do not perform disinfectant fogging for routine purposes in patient-care areas.

The manufacturer should be contacted for questions about disinfectants. A source of information about low level or intermediate level disinfectants is the Antimicrobial Program Branch, Environmental Protection Agency (EPA), Selected EPA-Registered Disinfectants (EPA) (703) 308-6411, on-line link https://www.epa.gov/pesticide-registration/selected-epa-registered-disinfectants, or email: info_antimicrobial@epa.gov.

High-Level Disinfection of Endoscopes

Endoscopes are fragile, expensive, difficult to clean, much used, and susceptible to contamination.¹⁴⁵ There are millions of endoscopic procedures done each year and iatrogenic infections caused by contamination of endoscopes are rare.^{145, 146} However, endoscopes have been linked to more infectious outbreaks than any other reusable medical device¹⁴⁶ and failure to properly clean and disinfect endoscopes is a primary reason why these outbreaks happen.¹⁴⁵ In addition, studies have shown that even cleaned and processed endoscopes are often contaminated.^148-150

The recommendations for the disinfection and sterilization of endoscopes listed below are from the CDC.^{145, 151} The American Society for Gastrointestinal Endoscopy has also published guidelines for cleaning endoscopes; there are also multi- medical society and the Society of Gastroenterology Nurses guidelines for this procedure, as well.^152-154

• To detect damaged endoscopes, test each flexible endoscope for leaks as part of each reprocessing cycle. Remove from clinical use any instrument that fails the leak test, and repair this instrument.
• Immediately after use, meticulously clean the endoscope with an enzymatic cleaner that is compatible with the endoscope. Cleaning is necessary before both automated and manual disinfection.
• Disconnect and disassemble endoscopic components (e.g., suction valves) as completely as possible, and completely immerse all components in the enzymatic cleaner. Steam sterilize these components if they are heat stable.
• Flush and brush all accessible channels to remove all organic (e.g., blood, tissue) and other residue. Clean the external surfaces and accessories of the devices by using a soft cloth or sponge or brushes. Continue brushing until no debris appears on the brush.
• Use cleaning brushes appropriate for the size of the endoscope channel or port (e.g., bristles should contact surfaces). Cleaning items (e.g., brushes, cloth) should be disposable; or, if they are not disposable, they should be thoroughly cleaned and either high-level disinfected or sterilized after each use.
• Discard enzymatic cleaners or detergents after each use. They are not microbicidal and, therefore, will not retard microbial growth.
• Process endoscopes (e.g., arthroscopes, cystoscope, and laparoscopes) that pass through normally sterile tissues by using a sterilization procedure before each use; if this is not feasible provide at least high-level disinfection. High-level disinfection of arthroscopes, laparoscopes, and cystoscopes should be followed by a sterile water rinse.
• Phase out endoscopes that are critical items (e.g., arthroscopes, laparoscopes) but cannot be steam sterilized. Replace these endoscopes with steam sterilizable instruments when feasible.
• Mechanically clean reusable accessories inserted into endoscopes (e.g., biopsy forceps or other cutting instruments) that break the mucosal barrier (e.g., ultrasonically clean biopsy forceps) and then sterilize these items between each use.
• Use ultrasonic cleaning of reusable endoscopic accessories to remove soil and organic material from hard-to-clean areas.
• Process endoscopes and accessories that contact mucous membranes as semi-critical items, and use at least high-level disinfection after use on each patient.
• Use an FDA-cleared sterilant or high-level disinfectant for sterilization, or high-level disinfection
• After cleaning, use formulations containing glutaraldehyde, glutaraldehyde with phenol/phenate, ortho-phthalaldehyde, hydrogen peroxide, and both hydrogen peroxide and peracetic acid to achieve high-level disinfection followed by rinsing and drying.
• Extend exposure times beyond the minimum effective time for disinfecting semi-critical patient-care equipment cautiously and conservatively because extended exposure to a high-level disinfectant is more likely to damage delicate and intricate instruments such as flexible endoscopes. The exposure times vary among the Food and Drug Administration (FDA)-cleared high-level disinfectants.
• Federal regulations are to follow the FDA-cleared label claim for high-level disinfectants. The FDA-cleared labels for high-level disinfection with >2% glutaraldehyde at 25°C range from 20-90 minutes, depending upon the product, based on three tier testing which includes AOAC sporicidal tests, simulated use testing with mycobacterial and in-use testing.
• Several scientific studies and professional organizations support the efficacy of >2% glutaraldehyde for 20 minutes at 20ºC; that efficacy assumes adequate cleaning prior to disinfection, whereas the FDA-cleared label claim incorporates an added margin of safety to accommodate possible lapses in cleaning practices. Facilities that have chosen to apply the 20 minutes duration at 20ºC have done so based on the IMulti-society Guideline for Reprocessing Flexible Gastrointestinal Endoscopes.
• When using FDA-cleared high-level disinfectants, use manufacturers’ recommended exposure conditions. Certain products may require a shorter exposure time (e.g., 0.55% ortho-phthalaldehyde for 12 minutes at 20°C, 7.35% hydrogen peroxide plus 0.23% peracetic acid for 15 minutes at 20°C) than glutaraldehyde at room temperature because of their rapid inactivation of mycobacteria or reduced exposure time because of increased mycobactericidal activity at elevated temperature (e.g., 2.5% glutaraldehyde at 5 minutes at 35°C).
• Select a disinfectant or chemical sterilant that is compatible with the device that is being reprocessed. Avoid using reprocessing chemicals on an endoscope if the endoscope manufacturer warns against using these chemicals because of functional damage, with or without cosmetic damage.
• Completely immerse the endoscope in the high-level disinfectant and ensure all channels are perfused. As soon as is feasible, phase out non-immersible endoscopes.
• After high-level disinfection, rinse endoscopes and flush channels with sterile water, filtered water, or tap water to prevent adverse effects from retained disinfectant, e.g., disinfectant-induced colitis. Follow this water rinse with a rinse with 70% - 90% ethyl or isopropyl alcohol.
• After flushing all channels with alcohol, purge the channels using forced air to reduce the likelihood of contamination of the endoscope by waterborne pathogens and to facilitate drying.
• Hang endoscopes in a vertical position to facilitate drying.
• Store endoscopes in a manner that will protect them from damage or contamination.
• Sterilize or high-level disinfect both the water bottle used to provide intraprocedural flush solution and its connecting tube at least once daily. After sterilizing or high-level disinfection of the water bottle, fill it with sterile water.
• Maintain a log for each procedure in which an endoscope has been used and record the following: patient’s name and medical record number, the type of procedure and the date, the name of the endoscopic, the system used to reprocess the endoscope (if more than one system could be used in the reprocessing area), and the serial number or other identifier of the endoscope that was used.
• Design facilities where endoscopes are used and disinfected to provide a safe environment for healthcare professionals and patients. Use air-exchange equipment (e.g., the ventilation system, out-exhaust ducts) to minimize exposure of all persons to potentially toxic vapors (e.g., glutaraldehyde vapor). Do not exceed the allowable limits of the vapor concentration of the chemical sterilant or high-level disinfectant; these limits are set by the American Conference of Governmental Industrial Hygienists (ACGIH) and OSHA.
• Routinely test the liquid sterilant/high-level disinfectant to ensure minimal effective concentration of the active ingredient. Check the solution each day of use (or more frequently) using the appropriate chemical indicator (e.g., glutaraldehyde chemical indicator to test minimal effective concentration of glutaraldehyde) and document the results of this testing. Discard the solution if the chemical indicator shows the concentration is less than the minimum effective concentration. Do not use the liquid sterilant/high-level disinfectant beyond the reuse-life recommended by the manufacturer (e.g., 14 days for ortho-phthalaldehyde).
• Personnel assigned to reprocess endoscopes should be given device-specific reprocessing instructions to ensure proper cleaning and high-level disinfection or sterilization. Competency testing in these procedures should be done on a regular basis.
• Educate all personnel who use disinfectants and sterilants about the possible biologic, chemical, and environmental hazards of performing procedures that require these products.
• The appropriate PPE should be provided to the staff who clean and disinfect endoscopes.
• If using an automated endoscope reprocessor (AER), place the endoscope in the reprocessor, and attach all channel connectors according to the AER manufacturer’s instructions to ensure exposure of all internal surfaces to the high-level disinfectant/chemical sterilant.
• If using an AER, ensure the endoscope can be effectively reprocessed in the AER. Also, ensure any required manual cleaning/disinfecting steps are performed (e.g., elevator wire channel of duodenoscopes might not be adequately disinfected by most AERs).
• Review the FDA advisories and the scientific literature for reports of deficiencies that can lead to infection because design flaws and improper operation and practices have compromised the effectiveness of AERs.
• Develop protocols to ensure that users can readily identify an endoscope that has been properly processed and is ready for patient use.
• Do not use the carrying case designed to transport clean and reprocessed endoscopes outside of the healthcare environment, to store an endoscope, or to transport the instrument within the healthcare environment.
• No recommendation is made about routinely performing microbiologic testing of either endoscopes or rinse water for quality assurance purposes.
• If environmental microbiologic testing is conducted, use standard microbiologic techniques.
• If a cluster of endoscopy-related infections occurs, investigate potential routes of transmission (e.g., person-to-person, common source) and reservoirs.
• Report outbreaks of endoscope-related infections to persons responsible for institutional infection control and risk management and to the FDA. Notify the local and the state health departments, CDC, and the manufacturer(s).
• No recommendation is made regarding the reprocessing of an endoscope again immediately before use if that endoscope has been processed after use according to the recommendations in this guideline.
• Compare the reprocessing instructions provided by both the endoscope’s and the AER’s manufacturer’s instructions and resolve any conflicting recommendations.

Disinfection Strategies for Other Semi-Critical Devices

Other medical devices aside from endoscopes that contact mucous membranes and are considered to be semi-critical include (but are not limited to) rectal and vaginal probes, flexible cystoscopes, tonometers, and ultrasound probes used for various procedures. The risk of contracting an infectious disease from one of these devices is very small but not impossible,¹⁵⁵ and contamination with microorganisms such as cytomegalovirus, human papilloma virus, hepatitis C, herpes simplex, Klebsiella, and Pseudomonas have been found on these devices, even after cleaning and disinfection.^156-160
Disinfection strategies vary widely for these semi-critical items devices, and the FDA requests the manufacturers to provide at least one validated cleaning and disinfection/sterilization protocol in the labeling for their devices. The CDC guidelines are listed below; disinfection and sterilization with different forms of hydrogen peroxide or ultra violet light are also being evaluated for sterilizing these types of devices.

• Even if probe covers have been used, clean and high-level disinfect semi-critical devices such as rectal probes, vaginal probes, and cryosurgical probes with a product that is not toxic to staff, patients, probes, and retrieved germ cells (if applicable). Use a high-level disinfectant at the FDA-cleared exposure time.
• When probe covers are available, use a probe cover or a condom to reduce the level of microbial contamination. Do not use a lower category of disinfection or cease to follow the appropriate disinfectant recommendations when using probe covers because these sheaths and condoms can fail.
• After high-level disinfection, rinse all items. Use sterile water, filtered water, or tap water followed by an alcohol rinse for semi-critical equipment that will have contact with mucous membranes of the upper respiratory tract, e.g., the nose, pharynx, and esophagus.
• There is no recommendation to use sterile or filtered water rather than tap water for rinsing semi-critical equipment that contacts the mucous membranes of the rectum (e.g., rectal probes, anoscope) or vagina (e.g., vaginal probes).
• Wipe clean tonometer tips and disinfect them by immersing them for 5-10 minutes in either 5000 ppm chlorine or 70% ethyl alcohol. None of these listed disinfectant products are FDA-cleared high-level disinfectants.

Sterilization¹⁴⁵

Steam is the preferred method for sterilizing critical medical and surgical instruments that are not damaged by heat, steam, pressure, or moisture.

• Cool steam or heat-sterilized items before they are handled or used in the operative setting.
• Follow the sterilization times, temperatures, and other operating parameters (e.g., gas concentration, humidity) recommended by the manufacturer(s) of the instruments, the sterilizer, and the container or wrap used, and that are consistent with guidelines published by government agencies and professional organizations.
• Use low-temperature sterilization technologies (e.g., EtO, hydrogen peroxide gas plasma) for reprocessing critical patient-care equipment that is heat or moisture sensitive.
• Completely aerate surgical and medical items that have been sterilized in the EtO sterilizer (e.g., polyvinyl chloride tubing requires 12 hours at 50^oC, 8 hours at 60^oC) before using these items in patient care.
• Sterilization using the peracetic acid immersion system can be used to sterilize heat-sensitive immersible medical and surgical items.
• Critical items that have been sterilized by the peracetic acid immersion process must be used immediately.
• Dry-heat sterilization at 340^oF for 60 minutes can be used to sterilize items like powders and oils that can sustain high temperatures.
• Comply with the sterilizer manufacturer’s instructions regarding the sterilizer cycle parameters.
• Because narrow-lumen devices provide a challenge to all low-temperature sterilization technologies and direct contact is necessary for the sterilant to be effective, ensure that the sterilant has direct contact with contaminated surfaces (e.g., scopes processed in peracetic acid must be connected to channel irrigators).

Packaging¹⁴⁵

• Packaging materials must be compatible with the sterilization process and have received FDA 510[k] clearance.
• Packaging must be strong enough to resist punctures and tears and to provide a barrier to microorganisms and moisture.

Monitoring of Sterilizers¹⁴⁵

• Use mechanical, chemical, and biologic monitors to ensure the effectiveness of the sterilization process.
• Monitor each load with mechanical (e.g., time, temperature, pressure) and chemical (internal and external) indicators. If the internal chemical indicator is visible, an external indicator is not needed.
• Do not use processed items if the mechanical or chemical indicators suggest inadequate processing.
• Use biologic indicators to monitor the effectiveness of sterilizers at least weekly with an FDA-cleared commercial challenge preparation for spores (e.g., a Geobacillus stearothermophilus for steam) intended specifically for the type and cycle parameters of the sterilizer.
• After a single positive biologic indicator used with a method other than steam sterilization, treat as nonsterile all items that have been processed in that sterilizer, dating from the sterilization cycle having the last negative biologic indicator to the next cycle showing satisfactory biologic indicator results. These nonsterile items should be retrieved if possible and reprocessed.
• After a positive biologic indicator with steam sterilization, objects other than implantable objects do not need to be recalled because of a single positive spore test unless the sterilizer or the sterilization procedure is defective as determined by maintenance personnel or inappropriate cycle settings. If additional spore tests remain positive, consider the items nonsterile and recall and reprocess the items.
• Use biologic indicators for every load containing implantable items and quarantine items, whenever possible, until the biologic indicator is negative.

	Indicator tapes provide a seal for sterilization packs and an immediate identification of processed items. Dispensers are available in all sizes
	Internal CI's should be used within each pouch or package, tray , or container. Class 5 integrators should be used in conjunction with physical monitoring and biological indicator testing for verifying the efficacy a sterilization system. (See AAMI ST79:2006)

Load Configuration¹⁴⁵

• Place items correctly and loosely into the basket, shelf, tray, or cart of the sterilizer. This will ensure that the penetration of the sterilant is not impeded.

Storage of Sterile Items¹⁴⁵

• The sterile storage area should be well ventilated and provide protection against dust, moisture, insects, and temperature and humidity extremes.
• Store sterile items so the packaging is not compromised (e.g., punctured, bent).
• The shelf life of a packaged sterile item depends on the quality of the wrapper, the storage conditions, the conditions during transport, the amount of handling, and other events like moisture that compromise the integrity of the package. If event-related storage of sterile items is used, then packaged sterile items can be used indefinitely unless the packaging is compromised.
• Evaluate packages for loss of integrity before use; look to see if they are torn, wet, or punctured. The pack can be used unless the integrity of the packaging is compromised.
• If the integrity of the packaging is compromised, repack and reprocess the pack before use.
• If time-related storage of sterile items is used, label the pack at the time of sterilization with an expiration date. Once this date expires, reprocess the pack.

Quality Control¹⁴⁵

• Provide comprehensive and intensive training for all staff that is assigned to reprocess semi-critical and critical medical/surgical instruments to ensure they understand the importance of reprocessing these instruments.
• Compare the reprocessing instructions (e.g., for the appropriate use of endoscope connectors, the capping/non-capping of specific lumens) provided by the instrument manufacturer and the sterilizer manufacturer and resolve any conflicting recommendations by communicating with both manufacturers.
• Conduct infection control rounds periodically (e.g., annually) in high-risk reprocessing areas (e.g., the gastroenterology clinic, central processing); ensure reprocessing instructions are current and accurate and are correctly implemented. Document all deviations from policy. All stakeholders should identify what corrective actions will be implemented.
• The quality control program for sterilized items should include the following: a sterilizer maintenance contract with records of service; a system of process monitoring; air-removal testing for pre-vacuum steam sterilizers; visual inspection of packaging materials, and; traceability of load contents.
• For each sterilization cycle, record the type of sterilizer and cycle used; the load identification number; the load contents; the exposure parameters (e.g., time and temperature); the operator’s name or initials, and; the results of mechanical, chemical, and biological monitoring.
• Retain sterilization records (mechanical, chemical, and biological) for a time period that complies with standards, statutes of limitations, and state and federal regulations.
• Prepare and package items to be sterilized so that sterility can be achieved and maintained to the point of use. Consult the Association for the Advancement of Medical Instrumentation or the manufacturers of surgical instruments, sterilizers, and container systems for guidelines for the density of wrapped packages.
• Periodically review sterilization policies and procedures.
• Preventive maintenance on sterilizers should be done by qualified personnel who are guided by the manufacturer’s instruction.

Flash Sterilization

Flash sterilization (immediate-use steam sterilization, IUSS) was traditionally used for items that were needed immediately, but a traditionally sterilized one was not available. Flash sterilization involves placing items in a gravity displacement sterilizer for 3 minutes, at 27-28 pounds of pressure and a temperature of 132°C. It is an effective technique, but it has limitations, and it should only be used when necessary, not for convenience or to compensate for poor planning. Concerns have been raised by the CDC, the Association of Perioperative Registered Nurses (AORN), and others that flash sterilization has become overused and can cause adverse events.^161-163 The CDC and the Joint Commission have guidelines for the proper use of immediate use steam sterilization^{145, 164} and these guidelines are supported by the AORN.¹⁶⁵

These guidelines for flash sterilization are from the CDC.¹⁴⁵

• Do not flash sterilize implanted surgical devices unless doing so is unavoidable.
• If flash sterilization is needed for an implantable device, recordkeeping is essential: the load identification, the patient’s name, and the biological indicator result must be carefully documented.
• Do not use flash sterilization for convenience, to avoid purchasing additional instrument sets, or to save time.
• When using flash sterilization, make sure the following parameters are met: 1) clean the item before placing it in the sterilizing container (a container that is FDA approved for use with flash sterilization) or tray; 2) prevent exogenous contamination of the item during transport from the sterilizer to the patient, and; 3) monitor sterilizer function with mechanical, chemical, and biologic monitors.
• Do not use packaging materials and containers in flash sterilization cycles unless the sterilizer and the packaging material/container are designed for this use.
• When necessary, use flash sterilization for patient-care items that will be used immediately, e.g., to reprocess an inadvertently dropped instrument.
• When necessary, use flash sterilization for processing patient-care items that cannot be packaged, sterilized, and stored before use.

The Joint Commission recommendations for immediate use of steam sterilization¹⁶⁴:

• Review the equipment manufacturer’s instruction to determine if IUSS is appropriate for a device or instrument.
• Circumstances in which IUSS is an appropriate technique are: 1) when a specific instrument is needed for an emergency procedure; 2) when a non-replaceable instrument has been contaminated but needs to be used immediately, and; 3) when an item was dropped on the floor but is needed immediately.
• The use of IUSS does not mean that the proper cleaning and transport steps can be omitted.
• Items that are suitable for IUSS must be processed in approved/validated containers that are suitable for IUSS.
• IUSS should not be used for mere convenience or due to limited instruments or equipment for the number of cases/procedures performed.
• Evaluate the IUSS process in all locations that it is being performed.

Adhere to the FDA enforcement document for single-use devices reprocessed by hospital. FDA requires hospitals to use the same standards by which it regulates the original equipment manufacturer.¹⁶⁶

Exceptional circumstances that require non-critical items to be either dedicated to one patient or patient cohort or subjected to low-level disinfection between patient uses are those involving^{73, 167, 168}:

• Patients infected or colonized with VRE other drug-resistant microorganisms judged by the infection control program, based on current state, regional, or national recommendations, to be of special or clinical or epidemiologic significance 

or

• Patients infected with highly virulent microorganisms, e.g., viruses causing hemorrhagic fever such as Ebola or Lassa.

Disinfectants can be a source of microbial contamination,^169-172 and hospital-acquired infections caused by contaminated disinfectants have been documented.^169-172 
These measures should be used to reduce the occurrence of contaminated disinfectants¹⁴⁵:

• Prepare the disinfectant correctly to achieve the manufacturer’s recommended use-dilution.
• Prevent extrinsic contamination of germicides, e.g., container contamination or surface contamination of the healthcare environment where the germicides are prepared and/or used 
• The instructions on the disinfectant labels in terms of shelf life, storage, dilution, proper use, disposal, and material compatibility must be followed.
• The user is responsible for any harm caused by off-label use.

The home environment should be as safe as hospitals or ambulatory care. Epidemics should not be a problem, and cross-infection should be rare. The healthcare provider is responsible for providing the responsible family member information about infection-control procedures to follow in the home, including hand hygiene, proper cleaning and disinfection of equipment, and safe storage of cleaned and disinfected devices.

• Among the products recommended for home disinfection of reusable objects are bleach, alcohol, and hydrogen peroxide. The Associations for Professionals in Infection Control and Epidemiology (APIC) recommends that reusable objects (e.g., tracheostomy tubes) that touch mucous membranes be disinfected by immersion in 70% isopropyl alcohol for 5 minutes or in 3% hydrogen peroxide for 30 minutes. Additionally, a 1:50 dilution of 5.25%–6.15% sodium hypochlorite (household bleach) for 5 minutes should be effective.
• Non-critical items like blood pressure cuffs and crutches can be cleaned with a detergent. Blood spills should be handled according to OSHA regulations. In general, sterilization of critical items is not practical in homes but theoretically, could be accomplished by chemical sterilants or boiling.
• Single-use disposable items can be used or reusable items sterilized in a hospital.
• Some environmental groups advocate environmentally safe products as alternatives to commercial germicides in the home-care setting. These alternatives (e.g., ammonia, baking soda, vinegar, borate-based products, liquid detergents) are not registered with the EPA as disinfectants or germicides, and they should not be used for disinfecting because they are ineffective against S. aureus. Borate-based products, baking soda, and detergents also are ineffective against Salmonella typhi and E coli; however, undiluted vinegar and ammonia are effective against S typhi and E coli. Common commercial disinfectants designed for home use also are effective against selected antibiotic-resistant bacteria.
• Public concerns have been raised that the use of antimicrobials in the home can promote the development of antibiotic-resistant bacteria. This issue is unresolved and needs to be considered further through scientific and clinical investigations.
• The public health benefits of using disinfectants in the home are unknown. However, some facts are known: many sites in the home kitchen and bathroom are microbially contaminated, the use of hypochlorites markedly reduces bacteria, and good standards of hand and food hygiene can help reduce infections in the home. In addition, laboratory studies indicate that many commercially prepared household disinfectants are effective against common pathogens and can interrupt surface-to-human transmission of pathogens. The “targeted hygiene concept”- which means identifying situations and areas like the bathroom and food preparation areas where risk exists for transmission of pathogens may be a reasonable way to identify when disinfection might be appropriate.

Construction activities in or near healthcare facilities cause increase disease risks for airborne and waterborne disease, and infections caused by construction activity have been well documented.^{173, 174} The increasing age of healthcare facilities is generating the ongoing need for repair and remediation work that can introduce or increase contamination of the air and water in patient-care environments. The CDC has further recommendations for construction activity in healthcare facilities that should be reviewed if applicable.¹⁷⁵

The purpose of heating, ventilation, and air conditioning (HVAC) systems in healthcare facilities is to a) maintain the indoor air temperature and humidity at comfortable levels; b) control odors; c) remove contaminated air; d) facilitate air-handling requirements to provide protection from airborne, healthcare-related pathogens; e) direct air flow; f) manage outside air; g) provide reliable filtration, and; h) minimize the risk of transmission of airborne pathogens.^{175, 176} Decreased performance of healthcare facility HVAC systems, filter inefficiencies, improper installation, and poor maintenance can contribute to the spread of healthcare related airborne infections. The CDC has further recommendations for HVAC systems in healthcare facilities that should be reviewed if applicable.¹⁷⁵

Hospital-acquired pneumonia is a significant cause of morbidity and mortality. This section will discuss risk factors for hospital-acquired pneumonia and methods/techniques for preventing hospital-acquired pneumonia (which is sometimes referred to as healthcare-associated pneumonia) in patients who are mechanically ventilated and those who are not.

Risk Factors

The most important risk factor for hospital-acquired pneumonia is mechanical ventilation. Other risk factors include¹⁸⁰:

• Age > 55 years
• Anemia
• Aspiration
• Chest or upper abdominal surgery
• Chronic lung disease
• Chronic renal failure
• Depressed consciousness
• Frequent ventilator circuit changes
• Increased gastric pH, e.g. from therapeutic use of H2 blockers or proton pump inhibitors
• Intracranial pressure monitoring
• Malnutrition
• Medications, e.g., glucocorticoids, muscle relaxers, opioids
• Multiple central venous catheter placements
• Multiple surgeries
• Multiple trauma
• Paralysis
• Prolonged intubation, re-intubation

Preventing Hospital-Acquired Pneumonia

For mechanically ventilated patients, measures that can prevent hospital- acquired pneumonia include avoiding intubation when possible, elevating the head of the bed, oral hygiene with an antiseptic, maintaining physical conditioning, minimizing the use of sedation, minimizing pooling of secretions above the endotracheal tube, proper maintenance of ventilator circuit, and staff education.¹⁸⁰

There has been comparatively little research on the prevention of hospital acquired pneumonia in the non-ventilated patient, but proper positioning, early identification and treatment of dysphagia, good oral hygiene, using an antiseptic mouth rinse, and conscientious use of Standard Precautions and infection control techniques may be helpful.¹⁸¹

The following are the CDC and the American Thoracic Society recommendations for the prevention of hospital-acquired pneumonia.^{182, 183} Recommendations from the Institute for Healthcare Improvement are included, as well.¹⁸⁴

Staff education: Staff knowledge of the risks of hospital-acquired pneumonia and their knowledge of, and compliance with prevention techniques are critical for reducing the incidence and severity of this disease.

Conduct surveillance in ICU patients: Do not routinely perform surveillance cultures of patient, equipment or devices

Sterilization and Disinfection:

• Thoroughly clean all equipment. When possible use steam sterilization or high-level disinfection by wet heat pasteurization
• Use sterile water for rinsing reusable semi-critical respiratory equipment after chemical disinfection. If this not feasible, rinse with filtered water.
• Adhere to provisions in the FDA’s enforcement document for single-use devices that are reprocessed by third parties.
• Do not routinely sterilize or disinfect the internal machinery of mechanical ventilators.
• Do not routinely change the breathing circuit humidifiers based on duration of use. Clean only when visibly soiled or malfunctioning.
• Breathing-circuit tubing condensate: Periodically drain and discard any condensate. Make sure the condensate does not drain toward the patient. Wear gloves during procedure or handling of condensate. Wash hands with soap and water or with alcohol-based hand rub after the procedure.
• No recommendation can be made for placing a filter or trap at the distal end of the expiratory-phase tubing to collect condensate.
• Use sterile water to fill bubbling humidifiers
• No recommendation can be made for the preferential use of a close, continuous-feed humidification system.
• Ventilator breathing circuits with heat moisture exchange (HME): No recommendation can be made for the preferential use of either HMEs or heated humidifiers to prevent pneumonia in patients receiving mechanically assisted ventilation. Change an HME that is in use on a patient when it malfunctions mechanically or becomes visibly soiled. Do not routinely change an HME that is in use on a patient more frequently than every 48 hours. Do not routinely change the breathing circuit attached to an HME while it is in use on a patient
• Oxygen humidifiers: Follow manufacturers' instructions for the use of oxygen humidifiers. Change the humidifier-tubing (including any nasal prongs or mask) when it malfunctions or becomes visibly contaminated.
• Small-volume medication nebulizers and in-line and hand-held nebulizers: Between treatments on the same patient, clean, disinfect; rinse with sterile water (if rinsing is needed), and dry small-volume in-line or hand-held medication nebulizers. Use only sterile fluid for nebulization, and dispense the fluid into the nebulizer aseptically. Whenever possible, use aerosolized medications in single-dose vials. If multi-dose medication vials are used, follow manufacturers’ instructions for handling, storing, and dispensing the medications.
• Mist-tents: Between uses on different patients, replace mist tents and their nebulizers, reservoirs, and tubing with those that have been sterilized or had high-level disinfection. No recommendation can be made about the frequency of routinely changing mist-tent nebulizers, reservoirs, and tubing while in use on one patient. Mist-tent nebulizers, reservoirs and tubing that are used on the same patient to should receive daily low-level disinfection (e.g., with 2% acetic acid) or pasteurization followed by air-drying.
• Other devices: Between uses on different patients, sterilize or subject to high-level disinfection portable respirometers and ventilator thermometers; reusable hand-powered resuscitation bags; no recommendation can be made about the frequency of changing hydrophobic filters placed on the connection port of resuscitation bags.
• Anesthesia machines and breathing systems or patient circuits: Do not routinely sterilize or disinfect the internal machinery of anesthesia equipment. Between uses on different patients, clean the reusable components of the breathing system or patient circuit and then sterilize or subject them to high-level liquid chemical disinfection or pasteurization in accordance with the device manufacturers’ instructions for their reprocessing. No recommendation can be made about the frequency of routinely cleaning and disinfecting unidirectional valves and carbon dioxide absorber chambers
• Follow published guidelines and manufacturers' instructions about in-use maintenance, cleaning, and disinfection or sterilization of other components or attachments of the breathing system or patient circuit of anesthesia equipment No recommendation can be made for placing a bacterial filter in the breathing system or patient circuit of anesthesia equipment
• Pulmonary-function testing equipment: Do not routinely sterilize or disinfect the internal machinery of pulmonary-function testing machines between uses on different patients. Change the mouthpiece of a peak flow meter or the mouthpiece and filter of a spirometer between uses on different patients.
• Room-air humidifiers and faucet aerators: Do not use large-volume room-air humidifiers that create aerosols unless they can be sterilized or subjected to high-level disinfection at least daily and filled only with sterile water.
• No recommendation can be made about the removal of faucet aerators from areas for immunocompetent patients
• If Legionella spp. are detected in the water of a transplant unit and until Legionella spp. are no longer detected by culture, remove faucet aerators in the unit

Tracheostomy Care and Suctioning

Good tracheostomy care reduces morbidity, and it also reduces the amount of time to decannulation.^{185, 186} Principles of good tracheostomy care include:

• All supplies to replace a tracheostomy tube should be at the bedside or within easy reach.
• Humidification should be used if the patient is mechanically ventilated or has thick secretions.
• Perform tracheostomy under aseptic conditions.
• When changing a tracheostomy tube, wear a gown, and use aseptic technique.
• No recommendation can be made for the daily application of topical antimicrobial agent(s) at the tracheostoma.
• Perform cuff pressure checks as needed.
• Cuffs should be deflated when the patient no longer needs mechanical ventilation.

Suctioning of respiratory tract secretions: Suctioning is an essential part of care for certain patients who are mechanically ventilated or have a tracheostomy, but it places them at risk for infection and hospital-acquired pneumonia. The following advice and recommendations can help prevent these complications.

• No recommendation can be made for the preferential use of either the multiuse closed-system suction catheter or the single-use open system suction catheter for prevention of pneumonia.^{187, 188}
• Sterile gloves do not have to be worn.¹⁸⁹
• No recommendation can be made about the frequency of routinely changing the in-line suction catheter of a closed-suction system in use on one patient.
• If the open-system suction is employed, use a sterile single-use catheter.
• Use only sterile fluid to remove secretions from the suction catheter if the catheter is to be used for re-entry into the patient's lower respiratory tract. Routine use of saline is not recommended.¹⁹⁰

Modifying Host Risk for Infection and Hospital-Acquired Pneumonia: Vaccination

Vaccination is an important part of protecting patients against hospital-acquired pneumonia and pneumonia. Patients at risk who should be given pneumococcal vaccination include^191-195:

• All infants and children age 2 to 59 months.
• Children 60 to 71 months with underlying medical conditions including immunocompetent children with chronic heart disease (particularly cyanotic congenital heart disease and heart failure), children who have cerebrospinal fluid leaks, chronic lung disease, asthma (if there is a need for high- dose corticosteroids), cochlear implants, or diabetes.
• Children with functional or anatomic asplenia, including sickle cell disease or other hemoglobinopathies, children who have congenital or acquired asplenia, or splenic dysfunction.
• Children with immunocompromising conditions including chronic renal failure, congenital immunodeficiency (includes B or T cell deficiency, complement deficiencies and phagocytic disorders; excludes chronic granulomatous disease), generalized malignancies, HIV infection, Hodgkin’s disease, nephrotic syndrome, leukemia, lymphoma, solid organ transplant, or other diseases requiring immunosuppressive drugs.
• Children ≥6 years, adolescents ≤18 years and adults ≥19 years.
• Person who have these underlying medical conditions: Anatomic asplenia, including sickle cell disease or other hemoglobinopathies, congenital or acquired asplenia; immunocompetent persons with cerebrospinal fluid leaks or cochlear implants; immunocompromising conditions including congenital or acquired immunodeficiency (this includes B or T cell deficiency, complement deficiencies and phagocytic disorders, excludes chronic granulomatous disease); HIV infection, chronic renal failure, nephrotic syndrome, leukemia, lymphoma, Hodgkin’s disease; generalized malignancies; solid organ transplant; multiple myeloma; or other diseases requiring immunosuppressive drugs (including long term systemic corticosteroids and radiation therapy).
• All adults ≥65 years.

No recommendation can be made for the routine administration of preparations of granulocyte colony stimulating factor (GCSF) medications or intravenous gamma globulin for prophylaxis against healthcare-associated pneumonia

No recommendation can be made for the routine administration of glutamine for prevention of healthcare-associated pneumonia.¹⁹⁶

Preventing Aspiration

Aspiration is a significant risk factor for hospital-acquired pneumonia and pneumonia. Measures that can prevent and decrease the risk for aspiration include^{180,181,197-199}:

• As soon as the clinical indications for their use are resolved, remove devices such as endotracheal, tracheostomy, or enteral tubes from patients.
• Limit the use of sedating or paralytic agents as these drugs can depress cough and other host-protective mechanisms.
• Maintain endotracheal tube cuff pressure at 20-30 cm H2O.
• Condensation in the ventilator circuit can become contaminated. Care should be taken to prevent condensation from reaching the lower airway or the nebulizer chamber.
• Use non-invasive ventilation (NIV) if possible; this will reduce the need for and duration of endotracheal intubation.
• If possible and if not medically contraindicated, use noninvasive positive-pressure ventilation delivered continuously by face or nose mask in preference to endotracheal intubation in patients who are in respiratory failure and who do not need immediate intubation.
• If possible and if not medically contraindicated, use NIV during the weaning process. This can shorten the duration of endotracheal intubation.
• As much as possible, avoid repeat endotracheal intubation in patients who have received mechanically assisted ventilation.
• Unless contraindicated by the patient’s condition, perform orotracheal rather than nasotracheal intubation.
• If feasible, use an endotracheal tube with a dorsal lumen above the endotracheal cuff to allow drainage (by continuous or frequent intermittent suctioning) of tracheal secretions that accumulate in the subglottic area.
• Before deflating the cuff of an endotracheal tube in preparation for extubation, tube removal or before moving the tube, clear secretions from above the cuff. Ensure that secretions are cleared from above the tube cuff.

Prevention of aspiration associated with enteral feeding^199-202:

• Maintain the head of the bed at 30-45° unless contraindicated.
• Routinely verify appropriate placement of the feeding tube, e.g., every four hours. Auscultating for air, checking the pH of the aspirate, and inserting the open end of a tube into water are not reliable methods of confirming tube placement; capnography is preferred. Radiographic confirmation is the gold standard.
• Routinely assess the patient’s tolerance for enteral feedings, e.g., every four hours.
• Gastric residual volume (GRV) does not correlate with the in the incidences of aspiration or pneumonia. Withholding feeding if the GRV is < 500 mL is contraindicated unless the patient has signs of feeding intolerance.
• Prokinetic medications such as metoclopramide should be used if possible.
• If the patient is at high-risk for aspiration or if he/she is intolerant to bolus delivery of enteral nutrition, deliver enteral nutrition by continuous infusion.
• Use sedatives sparingly.
• Consider a swallowing evaluation before oral feedings are started for recently extubated patients who had been intubated for more than 2 days.
• No recommendation can be made for using small-bore tubes for enteral feeding.
• Feedings can be delivered in the stomach, the jejunum, or the duodenum. The selection of the delivery site should be made on a case-by-case basis; if the patient has a high-risk for aspiration, a site lower than the stomach is preferred.

Prevention or modulation of oropharyngeal colonization

Bacteria are present in the oral cavity, both normal flora and bacteria that are transmitted to the patient during hospitalization. Aerobic and facultatively anaerobic gram-negative bacilli frequently colonize the oral cavities in patients who are hospitalized and/or immunocompromised. These pathogens are a significant cause of hospital-acquired pneumonia.²⁰³

Patients who are mechanically ventilated have an increase in oral biofilm, xerostomia, colonization of the oral cavity by pathogens, and no ability to self-clean, all of which increase the risk for ventilator-associated pneumonia.²⁰⁴

Oropharyngeal cleaning and decontamination with an antiseptic agent can help reduce the number of these pathogens and reduce the incidence of hospital-acquired pneumonia and ventilator-acquired pneumonia.^203-207

Chlorhexidine is the most commonly used and studied oral antiseptic for the prevention of oral decolonization and prevention of hospital-acquired pneumonia, but it is not clear which antiseptic agent is the most effective, and the optimal oral hygiene protocol has not been determined.^{204, 208}

Develop and implement a comprehensive oral-hygiene program (that might include the use of an antiseptic agent) for patients in acute-care settings or residents in long-term care facilities who are at high-risk of developing healthcare-associated pneumonia

No recommendation can be made for the routine use of an oral chlorhexidine rinse for the prevention of healthcare associated pneumonia in all postoperative or critically ill patients or other patients at high risk for pneumonia.²⁰⁹

Prevention of gastric colonization

Mechanical ventilation for > 48 hours is considered a risk factor for stress ulcer and gastrointestinal bleeding,²¹¹ and stress ulcer prophylaxis is recommended for these patients.²¹⁰

Oral proton pump inhibitors, oral or IV, are the drug of choice.²¹¹ Antacids, histamine-2 receptor blockers, and sucralfate can also be used.²¹⁰ Evidence comparing the proton pump inhibitor, antacids, histamine-2 receptor blockers, and sucralfate in terms of efficacy and safety appear to favor the proton pump inhibitors, but studies are few and limited in scope.

There is evidence that stress ulcer prophylaxis decreases the incidence of stress ulcers and bleeding but that it increases the risk for nosocomial pneumonia.211 However, experts feel that this risk is preferable to the development of stress ulcer and bleeding and that the studies that have associated stress ulcer prophylaxis with nosocomial pneumonia had methodologic flaws and were poorly controlled for co-morbidities.²¹¹

Enteral nutrition may have a protective effect against stress ulcer. But unless it is contraindicated, patients who are receiving enteral nutrition and need stress ulcer prophylaxis should be treated with a proton pump inhibitor or another protective drug.²¹¹

Prevention of postoperative pneumonia

Patients who are at-risk for developing post-operative pneumonia include²¹²:

• Age > 50
• Chronic corticosteroid use
• Chronic obstructive pulmonary disease
• Comorbid disease (ASA class ≥2)
• Congestive heart failure
• Consumption of >2 alcoholic drinks per day within two weeks
• Functional dependence
• History of stroke
• Impaired sensorium
• Obstructive sleep apnea
• Preoperative anemia and/or transfusion
• Preoperative hypoxemia
• Preoperative sepsis
• Preoperative transfusion of >4 units of packed red blood cells
• Pulmonary hypertension
• Smoking
• Respiratory infection within past month
• Weight loss of >10% within six months

Interventions for preventing post-operative pneumonia include^{213, 214}:

• Staff education about their involvement in preventing post-operative pneumonia
• Coughing and deep breathing exercises
• Twice daily oral hygiene with chlorhexidine
• Pain control
• Ambulation as tolerated
• If applicable, head of the bed elevation to at least 30°
• Documentation of interventions and scheduled assessment of their effectiveness
• Chest physiotherapy is not routinely recommended for all postoperative patients at high risk for pneumonia.¹⁸¹

Other prophylactic procedures for prevention of hospital-acquired pneumonia/pneumonia

Antimicrobials are not recommended for preventing pneumonia in critically ill patients or in patients who are mechanically ventilated.²¹⁵
Selective decontamination of the digestive tract with antiseptics or antibiotics applied to the oropharynx has been shown to reduce the incidence of ventilator-associated pneumonia and hospital-associated pneumonia.¹⁸⁰

There is insufficient evidence to recommend glucocorticoids, pro-biotics, or silver-coated endotracheal tubes as effective prophylactic measures.¹⁸⁰

Routine turning of the patient or the use of automatically turning beds is not routinely recommended.¹⁸¹

Warm, stagnant water between 50°-122°F allows for the multiplication of Legionella pneumophila, and the organism grows in structures such as evaporative coolers, faucets, misters, showers, water heaters, and whirlpool baths.²¹⁶

Legionella pneumophilia is aspirated, or the aerosolized bacteria is inhaled into the lungs. One case of person-to-person transmission has been reported, but Legionnaires’ disease is not generally considered to be a contagious disease.²¹⁶ Standard Precautions are considered to be sufficient infection control technique when caring for a patient who has Legionnaires’ disease.⁷³

Factors that increase the risk of developing Legionnaires’ disease include^216-218:

• Age ≥ 50 years
• Chronic lung disease
• Chronic illnesses such as diabetes, hepatic failure, or renal failure
• Cigarette smoking (Current or past)
• Compromised immune system
• Exposure to hot tubs
• Glucocorticoid treatment
• Heavy drinking
• Systemic malignancy
• Travel outside the home (Staying in hotels)

Testing for Legionnaires’ disease should be done if^219,220:

• The patient has failed outpatient antibiotic treatment for community-acquired pneumonia.
• The patient has severe pneumonia, particularly if she/he requires intensive care.
• The patient is immunocompromised and has pneumonia.
• He/she has traveled away from their home within 10 days before the onset of illness.
• The patient has pneumonia, and there is a Legionnaires’ disease outbreak.
• The patient is at risk for Legionnaires’ disease with healthcare-associated pneumonia (pneumonia with onset > 48 hours after admission).
• The patient is > 50 years of age.

The Legionella bacteria grow in water systems, and there are multiple guidelines at the national, state, and local level for detecting, controlling and preventing Legionnaire’s disease in these systems.²²¹ However, it is interesting to note that some authors feel that routine testing of water is not helpful and that efforts should focus on control and prevention.²²² National guidelines for control and prevention of Legionnaire’s disease in healthcare facilities are available from the CDC,¹⁸² and some aspects of those guidelines are presented below.

Clinical laboratory testing: Periodically review the availability and clinicians’ use of laboratory diagnostic tests for Legionnaires disease. If clinicians do not routinely use the tests on patients with diagnosed or suspected pneumonia, implement measures to enhance clinicians’ use of the tests.

Water cultures: No recommendation can be made about routinely culturing water systems for Legionella spp. in healthcare facilities that do not have patient-care areas (i.e., transplant units) for persons at high-risk for Legionella infection

Transplant units: In facilities with hematopoietic stem-cell- or solid-organ transplantation programs, periodic culturing for Legionellae in water samples from the transplant unit(s) can be performed as part of a comprehensive strategy to prevent Legionnaires disease in transplant recipients

No recommendation can be made about the optimal methods (i.e., frequency, number of sites) for environmental surveillance cultures in transplant units.

Maintain a high index of suspicion for Legionellosis in transplant patients with healthcare-associated pneumonia even when environmental surveillance cultures do not yield Legionellae.

If Legionella spp. are detected in the water of a transplant unit and until Legionella spp. are no longer detected by culture, remove faucet aerators in areas for severely immunocompromised patients

Transplant units/positive cultures: If Legionellae are detected in the potable water supply of a transplant unit, and until Legionellae are no longer detected by culture:

• Decontaminate the water supply.
• Restrict severely immunocompromised patients from taking showers.
• Use water that is not contaminated with Legionella spp. for patients’ sponge baths
• Provide hematopoietic stem cell patients with sterile water for tooth brushing or drinking, and use sterile water for flushing nasogastric tubes
• Do not use water from faucets with Legionella-contaminated water in patients’ rooms to avoid creating infectious aerosols.
• If Legionella spp. are detected in the water of a transplant unit and until Legionella spp. are no longer detected by culture, remove faucet aerators in areas for severely immunocompromised patients.

Healthcare facilities that do not house and/or treat severely immunocompromised patients (e.g., hematopoietic stem cell transplant or solid-organ transplant recipients):

• If a case of laboratory-confirmed health-care-associated Legionnaires disease is identified, or when two or more cases of laboratory-confirmed, possible health-care--associated Legionnaires' disease occur within 6 months of each other: 1) Contact the local or state health department or the CDC if the disease is reportable in the state or if assistance is needed; 2) conduct an epidemiologic investigation by retrospectively reviewing of microbiologic, serologic, and postmortem data to identify previous cases, and 3) begin an intensive prospective surveillance for additional cases of health-care--associated Legionnaires disease.
• If there is no evidence of continued nosocomial transmissions, continue the intensive prospective surveillance for cases for >2 months after surveillance is begun.
• If there is evidence of continued transmission exists: 1) conduct an environmental investigation to determine the source(s) of Legionella spp. by collecting water samples from potential sources of aerosolized water and saving and subtyping isolates of Legionella spp. obtained from patients and the environment; 2) if a source is not identified, continue surveillance for new cases for >2 months and, depending on the scope of the outbreak, decide to either defer decontamination pending identification of the source(s) of Legionella spp. or proceed with decontamination of the hospital's water distribution system, with special attention to the specific hospital areas involved in the outbreak; and 3) if a source of infection is identified, promptly decontaminate the source.

Engineering/construction concerns: When a new building is constructed, place cooling towers in such a way that the tower drift is directed away from the facility's air intake system and design the cooling towers such that the volume of aerosol drift is minimized

For cooling towers, install drift eliminators, regularly use an effective biocide, maintain the tower according to manufacturers' recommendations, and keep adequate maintenance records.

Where practical and allowed by state law, maintain potable water at the outlet at >51ºC (>124ºF) or <20ºC (<68ºF), especially in facilities housing organ-transplant recipients or other patients at high- risk.

If water is maintained at >51ºC, use thermostatic mixing valves to prevent scalding

No recommendation can be made about the treatment of water with chlorine dioxide, heavy-metal ions, ozone, or ultraviolet light. Hospitals served by municipalities with monochloramine-treated water have had success in controlling Legionellae.

Staff education

Review of Disease Transmission, the Required Precautions, and Infection Control Techniques

Pertussis is transmitted by infected respiratory secretions that become airborne when someone coughs or sneezes. It is typically a mild, self-limiting disease but serious complications are possible. The incidence of pertussis had declined for many years but more and more cases are being reported each year, and given the fact that effective vaccination is available, this is a very unfortunate and preventable public health development.

Pertussis is a reportable disease, and the local and/or state health department should be notified about all confirmed and suspected cases of pertussis. Conduct active surveillance for cases of pertussis until 42 days after the onset of the last pertussis case.

Notify persons who have had close contact with a case of pertussis in the healthcare setting so that they can be monitored for symptoms of pertussis or administered appropriate chemoprophylaxis. A close contact is considered to be^{182, 223}:

• Living in the same household.
• Face-to-face contact with a patient who is symptomatic in the catarrhal or paroxysmal period of the illness.
• Sharing a confined space in close proximity for a prolonged period of time (e.g., >1 hour) with a symptomatic patient.
• Face-to-face exposure within 3 feet of a symptomatic patient.
• Direct contact with respiratory, oral, or nasal secretions from a symptomatic patient.

Preventing Pertussis Transmission/Vaccination

Droplet Precautions, Respiratory Hygiene/Cough Etiquette, and Standard Precautions should be used when caring for a patient who has pertussis.⁷³ Droplet Precautions should be used for up to 5 days after initiation of effective therapy.⁷³
Wear a surgical mask when within three feet of a patient with confirmed or suspected pertussis, when performing procedures or patient-care activities that are likely to generate sprays of respiratory secretions, or when entering the room of a patient with confirmed or suspected pertussis.¹⁸²

A single room is preferable, but cohorting is an option if needed.⁷³

Patients with confirmed pertussis should be in a private room, or if known not to have any other respiratory infection, in a room with other patient(s) with pertussis until after the first 5 days of a full course of antimicrobial treatment or 21 days after the onset of cough if unable to take antimicrobial treatment for pertussis.¹⁸²

Limit the movement and transport of a patient with diagnosed or suspected pertussis to essential purposes only. If a patient is transported out of the room, ensure that precautions are maintained.

Restrict symptomatic pertussis-infected healthcare professionals from work during the first 5 days of after beginning antimicrobial prophylaxis.¹⁸²

For symptomatic healthcare personnel, do diagnostic laboratory tests if they have signs/symptoms that are suggestive of pertussis (i.e., unexplained cough illness of >1 week duration, paroxysmal cough).¹⁸²

The following are the current recommendations for pertussis vaccination^{182, 224-226}:

• Infants and children should receive 5 doses of DTaP, usually administered at 2, 4, and 6 months, 15 through 18 months, and 4 through 6 years of age. DT can be used for infants and children who should not receive acellular pertussis-containing vaccines.
• Adolescents 11-18 years should receive a single dose of Tdap, preferably at 11 to 12 years of age.
• Pregnant women should receive a single dose of Tdap during every pregnancy, preferably at 27 through 36 weeks gestation. Tdap is recommended only in the immediate postpartum period before discharge from the hospital or birthing center for new mothers who have never received Tdap before or whose vaccination status is unknown.
• Adults 19 years or older who have never received a dose of Tdap should get one as soon as feasible, to protect themselves and infants. When feasible, Boostrix (GlaxoSmithKline) should be used for adults 65 years and older; however, either vaccine product administered to someone 65 years or older provides protection and may be considered valid. Providers should not miss an opportunity to vaccinate persons aged 65 years and older with Tdap, especially if they have close contact with infants.
• Adults should receive a single dose of Td every 10 years.
• A single dose of Tdap is recommended for healthcare personnel who have not previously received Tdap regardless of the time since their most recent Td vaccination. Priority should be given to vaccinating those who have direct contact with babies younger than 12 months of age.
• No recommendation can be made for routinely vaccinating adults, including healthcare professionals, with the acellular pertussis vaccine at regular intervals (e.g., every 10 years).

In LTCFs for children and children with prolonged stay in acute-care facilities, follow the recommendations of the ACIP for vaccinating children according to their chronologic age.

During an institutional outbreak of pertussis, accelerate scheduled vaccinations to infants and children aged <7 years who have not completed their primary vaccinations, as follows:

• Infants aged <2 months who are receiving their initial vaccination: Administer the first dose of the DTaP vaccine as early as age 6 weeks and the second and third doses at a minimum of 4-week intervals between doses. Give the fourth dose on or after age 1 year and >6 months after the third dose
• Other children aged <7 years: Administer DTaP vaccine to all patients who are aged <7 years and are not up-to-date with their pertussis vaccinations, as follows:
• Administer a fourth dose of DTaP vaccine if the child has had 3 doses of DTaP or diphtheria, tetanus and pertussis (DTP) vaccine, is >12 months old, and >6 months have passed since the third dose of DTaP or DTP vaccine; administer a fifth dose of DTaP vaccine if the child has had four doses of DTaP or DTP vaccine, is aged 4-6 years, and received the fourth vaccine dose before the fourth birthday
• No recommendation can be made for administering additional dose(s) of pertussis vaccine to children who have a history of well-documented pertussis disease (i.e., pertussis illness with either a B. pertussis-positive culture or epidemiologic linkage to a culture-positive case).

Post-Exposure Prophylaxis
The primary objective of post-exposure antimicrobial prophylaxis (PEP) is to protect at-risk individuals from death and serious complications from pertussis.²²⁷ The CDC’s recommendation for PEP for pertussis are^{73, 227}:

• Give PEP to all household contacts of a pertussis case. Antimicrobial prophylaxis given to asymptomatic household contacts within 21 days of onset of a cough in the index patient can prevent symptomatic infection.
• Providing PEP to persons within 21 days of exposure to an infectious pertussis case patient if they are at high-risk of severe illness or if they will have close contact with a person at high-risk of severe illness. People who fit the latter criteria are: 1) women in their third trimester of pregnancy and infants; 2) anyone who has a pre-existing health conditions that may be exacerbated by a pertussis infection, e.g., asthma that requires medical treatment or someone who is immunocompromised; 3) contacts who themselves have close contact with infants < 12 months, pregnant women, or individuals with pre-existing health conditions at risk of severe illness or complications; and 4) all contacts in high-risk settings that include infants aged <12 months or women in the third trimester of pregnancy, e.g., neonatal intensive care units, childcare settings, and maternity wards.

Post-exposure prophylaxis should be offered to close contacts and to healthcare workers who have had prolonged exposure to respiratory secretions.⁷³

Symptomatic healthcare personnel who are proven to have pertussis or personnel who are highly suspected of having pertussis should be given chemoprophylaxis.¹⁸²
Restrict symptomatic pertussis-infected healthcare professionals from work during the first 5 days of after beginning antimicrobial prophylaxis.¹⁸²

Staff Education

Review the process of disease transmission and infection control techniques.

Surveillance¹⁸²

Maintain a high index of suspicion for healthcare-associated pulmonary aspergillosis in severely immunocompromised patients. Establish a surveillance system for cases of healthcare-associated pulmonary aspergillosis. Promptly inform infection-control personnel Aspergillus sp. is isolated from cultures of specimens from patient’s respiratory tract. Periodically review the hospital's microbiologic, histopathologic, and postmortem data.

Do not perform routine, periodic cultures of the nasopharynx of asymptomatic patients at high-risk for aspergillosis.p;

Do not perform routine, periodic cultures of equipment or devices used for respiratory therapy, pulmonary function testing, or delivery of inhalation anesthesia in the hematopoietic stem cell transplant unit or of dust in rooms of hematopoietic stem cell transplant recipients

No recommendation can be made about routine microbiologic air sampling before, during, or after facility construction or renovation, or before or during occupancy of areas housing immunocompromised patients.

Prevention of Transmission of Aspergillus Spores

Aspergillus is a fungus, and Aspergillus spores are very common in the environment. Aspergillus is not a contagious disease, and aspergillosis is primarily a disease contracted by people who have a compromised immune system or chronic lung disease.Standard Precautions are considered sufficient when caring a patient who has an infection with Aspergillus.⁷³ Use Contact Precautions and Airborne Precautions if there is a massive soft tissue infection with copious drainage and repeated irrigations are needed.⁷³

There are numerous methods of preventing transmission of Aspergillus. The following recommendations are from the CDC and the Infectious Disease Society of America^{181, 228}:

• Allogeneic hematopoietic stem cell transplant patients should be placed in a protective environment (PE); details about PEs are provided later in this section.
• Highly immunosuppressed patients should be cared for in a HEPA-?ltered ward.
• If a PE is not possible, the patient should be in a private room. There should be no connection to construction sites, and plants or cut flowers should not be allowed in the room.
• Educate high-risk patients about infection prevention measures. Discharge planning should include recommendations for the patient to reduce mold exposure, e.g., avoiding working with mulch, avoiding gardening, and avoiding construction or renovation activities.
• Leukemia and transplant centers should perform regular surveillance for cases of invasive mold infection. If there is an increase over baseline or there are mold infections in patients who are not high-risk, a prompt search for the source should be done.
• Use proper dusting methods for patient-care areas designated for severely immunocompromised
• Wet-dust horizontal surfaces daily using cloth that has been moistened with an EPA-registered hospital disinfectant
• Avoid dusting methods that disperse dust, e.g., feather dusting.
• Keep vacuums in good repair and equip them with HEPA filters for use in areas with patients at high risk
• Do not use carpeting in hallways and rooms occupied by severely immunocompromised patients
• Avoid using upholstered furniture or furnishings in rooms occupied by severely immunocompromised patients.
• Minimize the length of time that immunocompromised patients in PEs are outside their rooms for diagnostic procedures and other activities.
• Instruct severely immunocompromised patients to wear a high efficiency respiratory-protection device (e.g., an N95 respirator) when they leave the PE during periods when construction, renovation, and/or other dust-generating activities are ongoing in and around the healthcare facility
• No recommendation can be made about the specific type of respiratory-protection device (e.g., surgical mask, N95 respirator) for use by a severely immunocompromised patient who leaves the PE during periods when there is no construction, renovation or other dust-generating activity in progress in or around the healthcare facility.
• Systematically review and coordinate infection-control strategies with personnel in charge of the facility’s engineering, maintenance, central supply and distribution, and catering services.
• Develop a water-damage response plan for immediate execution when water leaks, spills, and moisture accumulation occur to prevent fungal growth in the involved areas
• Do not use laminar air flow (LAF) routinely in PE
• During construction, demolition, or renovation activities, construct impermeable barriers between patient-care and construction areas to prevent dust from entering the patient-care areas
• Direct pedestrian traffic that comes from construction areas away from patient-care areas to limit the opening and closing of doors or other barriers that might cause dust dispersion, entry of contaminated air, or tracking of dust into patient-care areas.

Construction is a well-known and well-documented risk factor for the development of aspergillosis,^229-232 construction activity is a serious threat to patients who are immunocompromised, and preventive measures during construction are essential. When constructing specialized-care units with a PE for hematopoietic stem cell transplant, the patient rooms must be designed to minimize accumulation of fungal spores: 1) HEPA filtration of incoming air is recommended. 2) there must be directed room airflow, 3) there must be positive air pressure in patient's room in relation to the corridor, 4) the room must be well-sealed, and 5) there should be >12 air changes per hour.¹⁸¹

Other recommendations include^229-231:

• Install and maintain HEPA and other ?ltration systems as needed.
• Use targeted air sampling prior to the commissioning of a new ward or air-handling systems.
• Conduct an infection control risk assessment and conduct a review of the mechanical air ?ltration and supply to high-risk areas prior arrival of patients.
• Reduce as much as possible patients’ exposure to dust, stagnant water and damp areas.
• Consider targeted environmental sampling during any hospital construction.

Chemoprophylaxis

Patients who have prolonged neutropenia and who are at high risk for invasive aspergillosis should be given prophylactic treatment with one of these antifungal drugs: posaconazole, voriconazole, and/or micafungin.²²⁸

Adenovirus, parainfluenza virus, and respiratory syncytial virus (RSV) are common causes of self-limited respiratory infections in infants and children,²³³ and they can also cause diarrhea, keratoconjunctivitis, and pneumonia. In adolescents and adults, infections with these viruses are typically less severe than in infants and children.²³³ However, patients who are elderly, immunocompromised, those who have cardiopulmonary disease, or who have had hematopoietic stem cell transplants, and solid-organ transplant recipients may develop severe illnesses when infected,^{233, 234} and the respiratory syncytial virus is a very common nosocomial pathogen that can infect up to 50% of patients and staff.²³³ 

Transmission

• Adenovirus is transmitted by inhalation of short-range aerosols and droplets, inoculation of the virus into the conjunctival sac, direct contact with infected fomites, and possibly by the fecal-oral route.^{233, 235}
• Parainfluenza virus is transmitted by infected respiratory secretions via person-to-person contact, by large droplets, or by contact with infected fomites that carry respiratory secretions.^{233, 236}
• Respiratory syncytial virus is transmitted by coarse aerosols produced by coughing or sneezing. It is also transmitted by contact with contaminated fingers or fomites and by self-inoculation of conjunctival sacs and nares.²³³

Surveillance¹⁸²

• Healthcare personnel should be promptly notified of increase in the activity of adenovirus, parainfluenza virus, or RSV in the community. In addition, there should be mechanisms by which the appropriate healthcare personnel can promptly inform the local and state health departments of any increase in the activity of these viruses in their facility.
• In acute-care facilities during periods of increased prevalence of symptoms of viral respiratory illness in the community or the healthcare facility, and/or during the influenza and RSV season (December-March), use rapid diagnostic techniques as indicated in patients who are admitted to the healthcare facility with respiratory illness and who are at high risk for serious complications from viral respiratory infections, e.g., pediatric patients or patients who have chronic cardiac and/or pulmonary diseases or who are immunocompromised.
• No recommendation can be made for routinely conducting surveillance cultures for RSV or other respiratory viruses.
• In LTCFs, establish mechanism(s) for continuing surveillance to allow rapid identification of a potential outbreak in the facility.

Prevention of Transmission and Infection Control

• Adenovirus: Use Standard Precautions, and use Contact and Droplet Precautions for the duration of the illness.⁷³ Use Contact Precautions for diapered or incontinent persons for the duration of illness or to control institutional outbreaks.⁷³
• Parainfluenza virus: Use Standard Precautions, and use Contact and Droplet Precautions for the duration of the illness.⁷³ The parainfluenza virus can remain infectious in airborne droplets for approximately 1 hour and on environmental surfaces for several hours.²³⁶
• RSV: Use Standard Precautions, and for infants, young children, and patients who are immunocompromised, use Contact and Droplet Precautions for the duration of the illness.⁷³ Wear a mask according to the guidelines of Standard Precautions when caring for patients who are immunocompromised.⁷³
• Place a patient with diagnosed RSV, parainfluenza, adenovirus, or other viral respiratory tract infection in a private room when possible or in a room with other patients with the same infection and no other infection.¹⁸¹
• There is no adenovirus vaccine that is available to the general public,²³⁷ there is no vaccine for parainfluenza virus,²³⁶ and there is no vaccine for RSV.²³⁸ Palivizumab is a monoclonal antibody, and the American Academy of Pediatrics recommends that it be given to high-risk infants and young children likely to benefit from immunoprophylaxis based on factors such as gestational age, underlying medical conditions, and RSV seasonality.²³⁹
• Promptly perform rapid diagnostic laboratory tests on patients who are admitted with or who have symptoms of RSV infection after admission to the healthcare facility to facilitate early downgrading of infection-control precautions to the minimum required for each patient’s specific viral infection.
• Promptly perform rapid diagnostic laboratory tests on patients who are admitted with or who have symptoms of parainfluenza or adenovirus infection after admission to the healthcare facility to facilitate early downgrading of infection-control precautions to the minimum required for each patient’s specific viral infection and early initiation of treatment when indicated.¹⁸²
• Limit patient movement or transport in acute-care facilities to essential purposes.
• For a patient with diagnosed or suspected adenovirus, RSV or parainfluenza virus infection, ensure that precautions are maintained to minimize the risk of transmission of the virus to other patients and contamination of environmental surfaces or equipment by ensuring that the patient does not touch other persons’ hands or environmental surfaces with hands that have been contaminated with his/her respiratory secretions.¹⁸²
• Healthcare personnel who have signs and symptoms of an acute upper respiratory tract infection should not care for infants and other patients at high risk for complications from viral respiratory tract infections.
• When feasible, perform rapid diagnostic testing on healthcare personnel with symptoms of respiratory tract infection, especially those who provide care to patients at high-risk. Limit visitors, and do not allow persons who have symptoms of respiratory infection to visit pediatric patients, patients who chronic cardiac or pulmonary disease or patients who are immunocompromised.¹⁸²
• Perform rapid screening diagnostic tests for the particular virus known or suspected to be causing the outbreak on patients who are admitted with symptoms of viral respiratory illness. Promptly cohort the patients (according to their specific infections) as soon as the results of the screening tests are available. In the interim, when possible, admit patients with symptoms of viral respiratory infections to private rooms. ¹⁸²
• During an outbreak of healthcare-associated RSV infection, cohort personnel as much as practical (e.g., restrict personnel who give care to infected patients from giving care to uninfected patients).
• No recommendation can be made for routinely cohorting personnel during an outbreak of healthcare-associated adenovirus or parainfluenza virus infection.¹⁸²

Staff Education

Staff knowledge and use of infection control techniques for the prevention of influenza transmission are very important.²⁴⁰ However, there is ample evidence that for nurses knowledge of and perhaps more importantly, compliance with these techniques is less than ideal.^240-243 The CDC includes staff education in its recommendations for preventing seasonal influenza in healthcare settings,²⁴⁴ and staff education on this topic can make a positive difference.²⁴²

Surveillance

Healthcare facilities should have mechanisms in place to which healthcare personnel can be promptly notified about increased influenza activity in the community or if there is an in-house influenza outbreak.²⁴⁴ There should be a member of the staff who is specifically assigned for communicating with public health officials and the health care personnel.

Ensure that laboratory tests are made available to clinicians for prompt diagnosis of influenza.

Vaccination

Vaccination is one of the most effective methods for preventing transmission of influenza.^{241, 244}

In acute-care settings (including acute-care hospitals, emergency rooms, and walk-in clinics) or ongoing-care facilities (including physicians’ offices, public health clinics, employee health clinics, hemodialysis centers, hospital specialty-care clinics, outpatient rehabilitation programs, or mobile clinics), offer influenza vaccine to inpatients and outpatients at high-risk for complications from influenza, beginning in September and throughout the influenza season. Groups at high-risk for influenza-related complications include^{244, 245}:

• Children aged 6 through 59 months.
• All persons aged ≥50 years;
• Adults and children who have chronic pulmonary (including asthma) or cardiovascular (except isolated hypertension), renal, hepatic, neurologic, hematologic, or metabolic disorders (including diabetes mellitus).
• People who are immunosuppressed by disease, by medications, or by both.
• Women who are or will be pregnant during the influenza season.
• Children and adolescents (aged 6 months–18 years) who are receiving long-term aspirin therapy and who might be at risk for experiencing Reye syndrome after influenza virus infection.
• Residents of nursing homes and LTCFs.
• American Indians/Alaska Natives.
• Persons who are extremely obese (BMI ≥40).

Influenza vaccination is also recommended for^{244, 245}:

• Healthcare personnel who have patient contact, healthcare profession students, and anyone who has regular contact with nursing home or LTCF residents.
• Household contacts (including children) and caregivers of children aged ≤59 months and adults aged ≥50 years, particularly those who have contact with children aged <6 months.
• Household contacts (including children) and caregivers of persons with medical conditions that put them at high-risk for severe complications from influenza.

Vaccination should be offered before influenza activity in the community begins. Health care personnel should be offered vaccination by the end of October, if possible. Children aged 6 months through 8 years who require 2 doses should be given the first dose as soon as possible after vaccine becomes available, and the second dose ≥4 weeks later.²⁴⁵
In LCTFs, establish an SOP for timely administration of the inactivated influenza vaccine to high-risk persons.^{182, 245}

• Obtain consent for influenza vaccination (if such is required by local or state law) from every resident (or his/her guardian) at the time the resident is admitted to the facility or any time afterwards, before the next influenza season.
• Routinely vaccinate all residents unless medically contraindicated. If a resident is admitted during the winter months after completion of the facility’s vaccination program, offer the vaccine at the time of their admission.^{182, 245}

In other settings where healthcare is given (e.g., home healthcare agencies), vaccinate patients for whom vaccination is indicated, and refer patient’s household members and care givers for vaccination.¹⁸²

Preventing Person-to-Person Transmission

Preventing person-to-person transmission of influenza involves educating the public and the staff, identifying members of the public and patients who are likely to have influenza, and observing the proper infection control techniques.²⁴⁴ For the public and patients²⁴⁴:

• Patients and people visiting a healthcare facility should be instructed to inform healthcare personnel upon arrival if they have any signs/symptoms of a respiratory illness. In addition, they should be instructed in the need for and proper procedures for handwashing, Respiratory Hygiene/Cough Etiquette, and other appropriate infection control measures.
• If there is an increase in influenza activity in the community, minimize elective visits to healthcare facilities.
• Visual alerts should be at the entrance and in strategic places to provide patients and healthcare personnel about Respiratory Hygiene/Cough Etiquette, especially during periods when influenza virus is circulating in the community. These alerts should cover: How to use tissues to cover nose and mouth, where to dispose of contaminated items, how and where to hand wash, and how and when to use a facemask.
• Encourage persons with symptoms of respiratory infections to sit as far away from others as possible. During periods of increased community influenza activity, consider setting up triage stations that facilitate rapid screening of patients for symptoms of influenza and separation from other patients.
• Place patients with suspected or confirmed influenza in a private room or area. If this is not possible, consult with infection control and consider cohorting.

For healthcare personnel²⁴⁴:

• Healthcare personnel who have a fever and respiratory symptoms should not report to work. If they are at work, they should stop doing patient care, put on a facemask, and promptly notify the supervisor and infection control personnel/occupational health before leaving work.
• Healthcare personnel should not return to work for at least 24 hours after they no longer have a fever and without using fever-reducing medicines.
• They should be considered for temporary reassignment or exclusion from work for 7 days from symptom onset or until the resolution of signs and symptoms, whichever is longer, if returning to care for patients in a PE such as hematopoietic stem cell transplant patients.
• Healthcare personnel who develop signs/symptoms of an acute respiratory illness but are afebrile should be considered for evaluation by occupational health to determine the appropriateness of contact with patients. Influenza antiviral treatment should be considered in these cases. These same workers can be allowed to continue or return to work unless assigned to care for patients requiring a PE, or they should be considered for temporary reassignment or considered for exclusion from work for 7 days from symptom onset or until the resolution of all non-cough symptoms, whichever is longer.
• Employee health services should track absences related to influenza, review job tasks to ensure that personnel at high risk for exposure to those with suspected or confirmed influenza are given priority for vaccination, ensure that employees have prompt access to medical consultation and, if necessary, early treatment, and promptly identify individuals with possible influenza.

Infection control techniques are vitally important in preventing person-to-person transmission of influenza. In order to prevent the spread/transmission of influenza, healthcare personnel should strictly adhere to Standard Precautions, handwashing protocol, Respiratory Hygiene/Cough Etiquette, Droplet Precautions, and the proper use of PPE.²⁴⁴ Don a face mask when entering the room. Droplet precautions should be used if the patient has suspected or confirmed influenza for 7 days after illness onset or until 24 hours after the resolution of fever and respiratory symptoms, whichever is longer, while a patient is in a healthcare facility.²⁴⁴If a patient under Droplet Precautions requires movement or transport outside of the room, have the patient wear a face mask, if possible; use Respiratory Hygiene/Cough Etiquette; and hand hygiene. Be sure that the personnel who will be caring for/receiving these patients are aware of the clinical situation.²⁴⁴

Use caution when performing aerosol-generating procedures

Precautions for aerosol-generating procedures include performing these procedures only if they are medically necessary and cannot be postponed, limiting the number of personnel present,performing the procedures in an airborne infection isolation room if feasible, room doors should be kept closed except when entering or leaving the room, and entry and exit should be minimized; healthcare personnel should wear respiratory protection equivalent to a fitted N95 filtering facepiece respirator or equivalent N95 respirator and perform surface cleaning after the procedures.²⁴⁴

Perform environmental infection control

Environmental infection control includes cleaning and disinfection and engineering controls, e.g., air filtration systems, physical barriers.²⁴⁴

Control of Influenza Outbreaks – Vaccination and Chemoprophylaxis

Determine the outbreak strain. Vaccinate unvaccinated patients and healthcare personnel.

Early antiviral treatment is recognized as a safe and effective therapy that can shorten the duration of the illness and prevent complications.²⁴⁶Chemoprophylaxis should be given as soon as possible, and it is not advisable to wait for laboratory confirmation.²⁴⁶
At-risk patients who should receive prophylactic antiviral therapy include²⁴⁶:

• Adults ≥65 years of age
• American Indians/Alaska Natives
• Children < 2 years of age
• Patients who have chronic cardiac disease (except for hypertension alone); chronic pulmonary disease; hematologic; hepatic, or renal disorders; metabolic disorders including diabetes mellitus; neurologic/neurodevelopmental disorders, including disorders of the brain, spinal cord, peripheral nerve, and muscle, such as cerebral palsy, epilepsy seizure disorders, stroke, intellectual disability, moderate to severe developmental delay, muscular dystrophy, or spinal cord injury delay, muscular dystrophy, or spinal cord injury
• Patients who are immunosuppressed by way of disease, medical conditions, or drugs
• Patients who are morbidly obese, BMI >40
• Residents of LTCFs, nursing homes
• Women who are pregnant or postpartum (within 2 weeks after delivery)

Antiviral treatment is also recommended as early as possible for any patient with confirmed or suspected influenza who is hospitalized, a patient who has a severe, complicated, or progressive illness, or one who has a high risk for complications from influenza.²⁴⁶ The available antivirals are amantadine, oseltamivir, peramivir, rimantadine, and zanamivir and depending on the drug, oral, inhaled, and IV forms are available. The specific drug that should be used depends on the age of the patient, the clinical setting, and the strain of influenza.²⁴⁴ The CDC has published guidelines that can help clinicians make the proper choice of antivirals: Influenza (Flu). Influenza Antiviral Medications: Summary for Clinician, March 8, 2017; these can be viewed by using these links: the second link pertains to LTCFs.

https://www.cdc.gov/flu/professionals/antivirals/summary-clinicians.htm.²⁴⁶

https://www.cdc.gov/flu/professionals/infectioncontrol/ltc-facility-guidance.htm.²⁴⁷

Definitions

• Infectious disease is a clinically manifest disease of man or animal resulting from an infection.
• Communicable disease is an illness due to a specific infectious agent which arises through transmission of that agent from an infected person, animal, or inanimate reservoir to a susceptible host.
• Occupational health strategies, as applied to infection control, are a set of activities intended to assess, prevent, and control infections and communicable diseases in healthcare professionals.

Safety and health issues can best be addressed in the setting of a comprehensive prevention program that considers all aspects of the work environment and has employee involvement as well as management commitment. Implementing the use of improved engineering controls is one component of such a comprehensive program. Prevention strategy factors that must be addressed include implementation of needleless systems if possible, modification of hazardous work practices, administrative changes to address needle hazards in the environment (e.g., prompt removal of filled sharps disposal boxes), safety education and awareness, feedback on safety improvements, and action taken on continuing problems.

Occupational Exposure to Infectious Pathogens: Hepatitis B, Hepatitis C, HIV

Healthcare personnel who perform patient care are at risk for exposure to potentially dangerous pathogens, and the most common of these are hepatitis B (HBV), hepatitis C (HCV), and HIV. Fortunately, transmission of one of these highly virulent microorganisms from patient to provider and the development of an infection are rare occurrences. However, occupational exposures to pathogens such as HBV, HCV, and HIV are a common everyday experience in healthcare facilities and during patient care, and nurses and other healthcare professionals must understand the risks of exposure and how to protect themselves.

Hepatitis B, HCV, and HIV are (in the healthcare setting) primarily transmitted by exposure to contaminated blood, and this can occur by a percutaneous injury, i.e., a needle stick or a sharps exposure, or by contact with a mucous membrane or non-intact skin. The risk that a healthcare professional will acquire HBV, HCV, or HIV and develop an infection because of an occupational exposure depends on these factors^{248, 249}:

• Prevalence of the infectious pathogen in the general population and the patient population.
• Frequency of exposures to these pathogens.
• Nature of the exposure and efficiency of transmission for that exposure: percutaneous, mucosal, non-intact skin, or intact skin, a deep puncture versus a splash exposure, the amount of blood involved, the bore of the needle if there was a needle stick injury.
• The viruses that are present in the contaminated fluid and the titer of virus (i.e., the viral load) in that fluid.
• Availability and efficacy of pre- and post-exposure prophylaxis.
• The underlying health and immune system function of the exposed person.

Blood is the most important source of HBV, HCV, and HIV transmission to healthcare professionals. Other body fluids, such as cerebrospinal fluid, synovial fluid, pericardial fluid, pleural fluid, peritoneal fluid, and amniotic fluid are considered potentially infectious.^248-250 Semen and vaginal secretions can be a source of sexual transmission of these viruses, but there are no documented cases of transmission of HBV, HCV, or HIV in the occupational setting from exposure to semen or vaginal secretions.²⁵⁰ Other body fluids, e.g., feces, gastric secretions, nasal secretions, saliva, sputum, sweat, tears, and urine may contain low amounts of HBV, HCV, and HIV but unless these fluids are visibly contaminated with blood, they are not considered infectious.^248-250

An occupational exposure to HBV, HCV, or HIV is defined by Weber et al. as “contact with potentially infectious blood, tissue, or body fluids in a manner that allows for possible transmission of HIV and therefore requires consideration of post-exposure prophylaxis (PEP).” Exposure then would include needle stick or sharps injuries, puncture wounds, mucosal contact, or exposure of the non-intact skin, i.e., skin that is abraded.

Risk of Occupational Transmission/ Infection of HBV, HCV, and HIV

In descending order, the risk of transmission and development of infection after an occupational exposure is: HBV, HIV, and HCV.

Hepatitis B is highly infectious. The risk for transmission depends on the HBV surface antigen and HBV e antigen status of the source (and the previously mentioned factors), and this risk has been estimated to be 18%-62%.^{248, 251} The risk of developing hepatitis from an occupational exposure to HBV has been estimated to be from 1%-31%.²⁴⁸

Hepatitis C is less infectious than HBV. The CDC has estimated that the risk for seroconversion after an occupational exposure to HCV is 1.8%, with a range of 0-7%.²⁵² However, Egro et al.(2017) noted that the data used by the CDC to develop these numbers was from old sources, some of it was from non-US medical centers where universal precautions are not used as they should be, and that only needle stick injuries were assessed.²⁵³ These authors examined 1361 exposures over a 13 year period (mucous membrane exposures and percutaneous exposures) and found a seroconversion rate of 0.1%; the two cases of seroconversion happened after percutaneous exposure.²⁵³

Transmission of HIV from a patient to a healthcare professional is uncommon. The risk of seroconversion has been estimated to be 0.3% for percutaneous exposure and 0.09% per mucous membrane exposure²⁵⁴but as with risk estimations for HCV, these estimates have been criticized as possibly being too high and based on conditions that don’t reflect current exposure circumstances and the availability and effectiveness of post-exposure prophylaxis.²⁵⁵ Fortunately, confirmed cases of occupational transmission of HIV and subsequent HIV infection are rare, with 58 cases reported to the CDC between 1985 and 2013.²⁴⁹

Post-Exposure Care

• Any possible or potential occupational exposure to HBV, HCV, or HIV should be reported to the appropriate in-house person or department (e.g., supervisor, employee health) immediately or as soon as possible. Do not make the decision that an exposure is/is not a risk for transmission of HBV, HCV, or HIV. This decision is the responsibility of the person/department that evaluates risks and prescribes treatment. In several investigations of nosocomial HBV outbreaks, most infected healthcare professionals could not recall an overt percutaneous injury, although in some studies, up to one third of the infected persons recalled caring for a patient who was hepatitis B surface antigen positive, and HBV and HCV can survive on environmental surfaces for seven days and 16 hours, respectively.²⁴⁸ Treatment of exposures should focus on three areas: wound care, evaluation of the risk, and post-exposure drug prophylaxis.
• Wound care: The basics of wound care are the same for an exposure to HBV, HCV, or HIV.^248,249 Wash the wound with soap and water or flush the area with water. Antiseptics do have virucidal action, and they may be helpful but don’t delay basic wound care if an antiseptic is not close at hand.^248,249
• Evaluate the risk: This involves determining the circumstances of the exposure (e.g., time of exposure, how the exposure occurred) and determining the HBV, HCV, and HIV status of a patient who was the source of the exposure. Rapid HIV testing should be done on the source patient unless it is known that she/he is infected with HIV. The source patient should be tested for the presence of HBV unless it is known that he/she is infected with HBV or the healthcare professional has completed the three dose hepatitis vaccine series. Testing for HCV status should always be done unless it is known that the source has an HCV infection.^{248, 249} The health care professional should also be tested for the presence of HBV, HCV, and HIV, tetanus vaccination status should be determined, and a medical history, including a medication profile, should be obtained. For a HBV exposure, if the source patient was hepatitis B surface antigen positive or if the source patient’s HBV status could not be determined, the healthcare professional should be tested six months after the exposure.²⁴⁸ For an HCV exposure, testing should be done every two months for six months.²⁴⁸ Testing for HIV should be done immediately after the exposure, and if a fourth generation HIV assay test is done (preferred), retesting should be done at six weeks and four months after the exposure.²⁴⁹ Post-exposure drug prophylaxis, HBV exposure: The need for post-exposure drug prophylaxis after exposure to HBV depends on the HBV status of the source patient and the immunization status of the healthcare professional.²⁴⁸ There are a variety of possible circumstances, e.g., the source patient has an HBV infection, but the exposed person is a vaccine non-responder (the anti-HBs remains <10 mIU/mL after receiving the three dose hepatitis B vaccine series on two separate occasions); the source patient is positive, but the healthcare professional has responded to hepatitis B vaccination, or she/he has serologic evidence of a past HBV infection. The specific details of all the possible situations regarding when and for whom post-exposure drug prophylaxis should be used after an HBV exposure will not be covered here; they can be viewed at the Post-Exposure Prophylaxis Hotline website. However, key points to remember are: if the source patient is positive or her/his HBV status cannot be determined, administer the first dose of the hepatitis B vaccine series and one dose of hepatitis B immune globulin; and if hepatitis immune globulin is needed it is preferable that it be given within 24 hours of an exposure but this time limit can be extended to seven days.²⁴⁸ Women who are pregnant or breastfeeding can be vaccinated against HBV infection and/or receive hepatitis B immune globulin. Pregnant women who are exposed to blood should be vaccinated against HBV infection because infection during pregnancy can cause severe illness in the mother and a chronic infection in the newborn. The vaccine does not harm the fetus. During the follow-up period, anyone who has been exposed should not donate blood, organs, semen, or tissues.²⁴⁸
• Post-exposure drug prophylaxis, HCV exposure: Currently there are no medications that have been approved for post-exposure prophylaxis after an exposure to HCV,²⁴⁶ and the drug protocols with second generation protease inhibitor that are used to treat an HCV infection are not recommended for post-exposure prophylaxis.^{256, 257}
• Post-exposure drug prophylaxis, HIV exposure: Post-exposure drug prophylaxis for HIV exposure has been shown to be effective. It should be started as soon as possible, preferably within one-two hours after the exposure, and initiation of therapy should not be delayed while waiting for HIV test results.²⁴⁹ In certain situation, e g., an exposure that is high-risk, drug therapy can be started up to a week after an HIV exposure.²⁵³ Details about drug regimens can be viewed on the Post-Exposure Prophylaxis Hotline website. All of the antiviral drugs used to prevent HIV infection after an exposure have been associated with side effects. The most common side effects include nausea, vomiting, diarrhea, tiredness, or headache. The few serious side effects that have been reported in healthcare professionals using combination HIV post-exposure prophylaxis have included kidney stones, hepatitis, and suppressed blood cell production. Interaction with other medicines can cause serious side effects. Women who are pregnant should be given HIV post-exposure prophylaxis if necessary.²⁴⁹ These drug regimens may cause a slight increase in the rate of pre-term delivery and impaired fetal growth, but the evidence for these effects is conflicting.²⁵⁷ During the follow-up period, especially the first 6-12 weeks when most infected persons are expected to show signs of infection, the exposed person should follow recommendations for preventing transmission of HIV. These include not donating blood, semen, or organs and not having unprotected sexual intercourse. If the healthcare professional chooses to have sexual intercourse, using a condom consistently and correctly may reduce the risk of HIV transmission. In addition, women should consider not breastfeeding infants during the follow-up period to prevent exposing their infants to HIV in breast milk. During the follow-up period, anyone who has been exposed should not donate blood, organs, semen, or tissues.²⁴⁸

By calling 1-888-448-4911 from anywhere in the United States from 9:00 am to 9:00 pm, seven days a week, clinicians can gain access to the National Clinicians' Post-Exposure Prophylaxis Hotline (PEPline). The PEPline has trained physicians prepared to give clinicians information, counseling and treatment recommendations for professionals who have needle stick injuries and other serious occupational exposures to blood borne microorganisms that lead to such serious infections or diseases as HIV or hepatitis.

Other helpful resources are:
HIV Antiretroviral Pregnancy Registry. Address: Research Park, 1011 Ashes Drive, Wilmington, NC 28405. Telephone: 800-258-4263; fax: 800-800-1052. Email: registry@nc.crl.com.
FDA (for reporting unusual or severe toxicity to antiretroviral agents) at http://www.fda.gov/medwatch. Address: U.S. Food and Drug Administration, 10903 New Hampshire Avenue Silver Spring, MD 20993. Telephone: 800-332-1088.
U.S. Department of Health and Human Services. AIDS Info. Address: AIDSinfo, P.O. Box 4780, Rockville, MD 20849-6303. Telephone: 1-800-4448-0440; fax, 1-302-315-2818; TTY, 1-888-480-3739. Email: ContactUs@aidsinfo.nih.gov

Employers are required to establish exposure control plans that include post-exposure follow up for their employees and to comply with incident reporting requirements mandated by the 1992 OSHA bloodborne pathogen standard. Access to clinicians who can provide post-exposure care should be available during all working hours, including nights and weekends. Hepatitis B immune globulin, HBV vaccine, and antiretroviral agents for HIV post-exposure prophylaxis (PEP) should be available for timely administration, either by providing access on site or by creating linkages with other facilities or providers to make them available off-site.

Pre-exposure prophylaxis

Healthcare professionals should be well versed in the use of Standard Precautions and use them conscientiously. Anyone who may be exposed to blood or body fluids should be offered hepatitis B vaccination at no charge. There are no vaccines for the prevention of HCV of HIV infection.