≥ 92% of participants will know the pathology, management, and current clinical guidelines of HIV/AIDS.
CEUFast, Inc. is accredited as a provider of nursing continuing professional development by the American Nurses Credentialing Center's Commission on Accreditation. ANCC Provider number #P0274.
≥ 92% of participants will know the pathology, management, and current clinical guidelines of HIV/AIDS.
By the end of this activity, the participant will be able to:
Research compilations and epidemiological surveys tracing the origin of human immunodeficiency virus (HIV) have prominently recognized the last century as the biological point frame of the first report. According to multiple reports, the virus arose from several independent zoonotic transmissions of the simian immunodeficiency virus. Currently, the HIV epidemic is globally discussed concerning the spread and healthcare burden of the virulent HIV-1 and the less widespread HIV-2.
The HIV genome comprises two identical single-stranded ribonucleic acid (RNA) molecules enclosed within the core of the virus particle. By the reverse transcription of the viral RNA genome, the provirus HIV particles are generated. The process of provirus DNA generation also includes the degeneration of the single-stranded RNA molecules and the subsequent integration into the human DNA makeup. The arrangement of the DNA genomes impacts different stages, from viral invasions of cells to the maturation and replication of infectious virions; for instance, the 5' long terminal repeat region codes for the transcription of viral genes while the 'Gag gene' encodes the proteins of the outer core membrane. Although the overall genome of HIV appears simple, the complexities involved in cell entry and reprogramming are championed by a host of high-specific proteins in its envelope and core.
HIV Virion Structure
The mature HIV virion has these proteins functioning consistently to aid viral cells' sustenance and survival. At the mature stage, the virions attain a round shape and roughly measure about 100 nanometers (nm) in diameter. The proteins and other structural components of the mature virion are completely enclosed in an outer lipid membrane envelope. The outer envelope comprises 72 knobs functioning as trimers of the proteins resident in the envelope.
Beyond merely ensuring virus cell survival, the regulator proteins play significant roles in the different stages of viral replication, propagation, and virulence.
Rolia resides in a quiet suburb of Uganda, a third-world country battling a surge of HIV cases in recent years. With a rapidly increasing population, the primary healthcare system in this country is stretched too thin as self-care campaigns could only capture residents in the large metropolis. Rolia and other middle-aged women in the suburbs could only make do with local medicines or visit the metropolis in emergency cases. At 42, Rolia was diagnosed with chronic HIV after a brief illness characterized by intermittent fever, unexplained weight loss, upper abdominal pain, and non-resolving watery diarrhea. Initial examination identified Crysporidium parvum in her stool, and subsequent cultures identified other microbes implicated in HIV-related opportunistic infections, including Pneumocystis carinii and cytomegalovirus (CMV) retinitis.
She lost 21 kilograms (kg) in the past seven months and had also developed episodic pains in the joints of the lower limbs. On examination, Rolia's temperature was 39.5 C, her pulse was 97/min, and her blood pressure was 154/87 millimeters of mercury (mmHg). The reported laboratory examination is as follows:
Endoscopic examinations revealed a normal ilium with minimal gastrointestinal inflammation. A colonoscopy revealed clusters of Cryptosporidium in the colon and the upper ampulla. Gram staining of blood culture showed no organisms; however, acid-fast bacilli (AFB) blood cultures showed Mycobacterium avium complex. Rolia was immediately started on ethambutol and clarithromycin with a nursing plan to check her vitals every hour. About three days later, Rolia's condition improved as she admitted to having impressive symptomatic relief from the joint pains and the feverish condition. A week after conducting genotyping, she was started on tenofovir, lamivudine, and lopinavir/ritonavir. Rolia was then referred to an HIV adherence monitoring center in her hometown for therapy monitoring. A quarterly visit to the HIV therapy center in the metropolis was also scheduled to better evaluate Rolia's response to therapy and any drug side effects.
The global distribution of HIV cases, regardless of region and cultural affiliation, seems to follow a common pattern.
On a global scale, the healthcare burden of HIV was at 36.9 million cases in 2019, a count corresponding to an estimated 0.5% of the world's population (Govender et al., 2021). Cluster analysis showed that the global burden as of 2019 translates to about 476 cases per every 100,000 group in the population. Epidemiological estimates for new cases and cases under treatment peaked in 2005 and steadily declined for the next five years; this trend has been attributed to the wide circulation of antiretroviral (ART) therapy regimens and their efficacy in the human population. Since 2010, however, the incidence rate has reportedly been increasing steadily. As of 2021, the highest prevalence rates were recorded in South Africa, Portugal, the United States, Mexico, Brazil, Peru, Spain, and Germany. Portugal reported a very high prevalence rate, with an estimated increase from 86 per 100,000 people to 370 per 100,000. However, between 1999 and 2019, South Africa reported a significantly increased prevalence rate from 354 per 100,000 people to 14,251 per 100,000. In sub-Saharan Africa, regional epidemiological studies showed that new cases are particularly concentrated in Lesotho, Mozambique, South Africa, Zimbabwe, and Namibia.
Prevalence of HIV-AIDS in Africa
Trends in the age distribution of new cases show an irregular distribution, with the most peaks appearing in infancy and young adulthood. Infancy peaks correspond to increased perinatal transmission rates due to inadequate primary healthcare systems. In contrast, peaks at the adolescent stage correspond to an increase in adolescent risky behaviors, including needle sharing and drug abuse. Population clusters in the 20 – 39-year-old groups show the highest incidence rates. The Joint United Nations Programme on HIV/AIDS (UNAIDS) data on prevalence trends also attribute 500 in every 5,000 new cases to children. Young women residents in sub-Saharan Africa also appear to show a high level of susceptibility to the virus. Country-level epidemiological studies have identified the worst cases in Africa. Data from these studies identify South Africa as the worst affected country in the world today. In 2017 alone, about 7.9 million HIV cases across all age groups were reported, with the prevalence rate among men at 14.8% and 26.3% among the female population (Simbayi et al., 2019).
Referencing statistics published by the UNAIDS for 2022, the global burden of HIV was at 38.4 million in 2021, with 1.5 million new cases in the same year. The key at-risk population (gay men, sex workers, those who are transgender, and drug addicts) reportedly accounted for about 70% of all cases documented globally as of 2021. Regional distribution studies place 94% of new HIV infections outside of sub-Saharan Africa and 51% in sub-Saharan Africa. Risk estimates showed that the risk of new cases is 35 times higher in people who abuse injectable drugs, 30 times higher in female sex workers, 28 times higher among men who have sex with men, and 14 times higher in transgender women (Simbayi et al., 2019). Age-specific risk studies suggest a weekly count of about 4,900 young women aged 15-24 reporting new cases of infection. In sub-Saharan Africa, young women and girls aged between 15-24 years appear to be twice as likely to have an active HIV infection compared to men of the same age range.
Understanding the pathophysiology of HIV involves carefully examining the CD4 cells and their interaction with viral envelope proteins. The CD4+ helper T cells are key regulators of humans' innate and humoral immune response systems. These cells are prominently expressed on the surface of T-lymphocytes, monocytes, macrophages, and dendritic cells.
The HIV life cycle is complex, involving multiple series of carefully coordinated attacks on the host cell and an eventual hijacking of cell function. In the early life cycle phase, HIV virions attach to the cell surface and attempt cell entry. If successful, this phase usually ends with integrating proviral DNA into the host cell genome. In the late phase, viral replications start with the transcription of proviral particles and end with the release of virulent virions produced with the infrastructure of the host cell. Lasting between two to three days, viral invasion of healthy cells culminates in the death of infected host cells and other bystander cells. A widely studied phenomenon in this regard is the high virus cell variation rate. With a variation rate estimated at one mutation at every few complete replication cycles, HIV produces an extensive number of variants. However, the survival rates for each variant reportedly depend on the selective combined forces of the body's immune system and ART therapy. The combined forces of massive virion production (estimated as 2 x 109 virions per day) and the short generation time allow the virus to rapidly adapt to the host cell environment and survive against multiple odds. To properly capture the life cycle of HIV, this course will discuss the interaction between the host cell and the virus when discussing viral attachments, binding and fusion, viral entry, reverse transcriptions, uncoating and nuclear entry, integration, transcription, translation and assembly, maturation, and release.
Overview of the HIV Life Cycle Stages
In infected humans, HIV virions that are cell-free (yet to infect a cell) die out in about one hour. Cell-free virions must infect a healthy cell within a short time frame to survive. The process usually starts with recognizing and attaching to healthy cells with a CD4 receptor. The co-receptors C-C chemokine receptor type 5 (CCR5) and C-X-C motif chemokine receptor 4 (CXCR4) also play important roles in this early stage of infection.
As a rate-limiting step in viral infection, the pharmacological effects of agents that can lower the densities of the Env trimers or temporarily block the CD4 receptor sites have been extensively studied in infected individuals. To aid viral attachment, several receptors, including lectins and polyglycans, can also bind virions in an unspecific manner, ultimately increasing the viral infection rate. These additional receptors also appear as concentrated virions in the cells, aiding improved interaction between virions and cells with active CD4 receptors on their surfaces. Variant features may also determine the rate of viral attachment. For instance, individual virus strains with an envelope glycoprotein or gp120 variation express increased affinity for the co-receptors CCR5 and CXCR4.
Virion binding and fusion specifically initiate the infection cycle with the interaction of cell surface CD4 receptors with the external gp120 on the virion. The binding of the virion's external glycoprotein on the CD4 helper cells initiates a conformational cellular configuration in the Env trimer. The change in conformation further allows the secondary interaction of gp120 with either cofactors - CCR5 and CXCR4. Configurational changes of this nature do not end with the gp120-cofactor binding. Instead, cofactor binding further promotes a new type of binding that involves the gp41 transmembrane protein resident on the gp120 on the virion and the host cell membrane. Micro-imaging observations studying this interaction suggest that the gp41 inserts its hydrophobic fusion peptide apparatus into the host cell membrane in a final interaction that establishes transmembrane contact between the invading virion and the host cell environment (Bruxelle et al., 2021). Following this interaction, the gp41 complex forms a helical bundle that bridges the distance between the virion membrane and the cellular content – effectively pulling both environments together. The resulting complex is a fusion reaction as the virion's contents are released into the invaded cells. CCR5 receptor blockers and fusion inhibitors indicated for the management of HIV exert their pharmacological actions at this stage of infection.
After membrane fusion, reverse transcriptase interactions follow. The genetic components of the HIV genome, including its double-stranded RNA and nucleocapsid envelope, are fused with the host cell environment.
Following the successful generation of linear DNAs from the reverse transcription of viral double-stranded RNAs and its release into the cell nucleus, the viral genome is inserted into the cell genome; this is essential for cellular invasion, the expression of proteins, and the initiation of active viral infection.
Interrupting the integration or inhibiting the actions of integrase have been proposed as valid pharmacological methods of halting proviral cell survival. Drug compounds inhibiting integrase, integrase inhibitors – are currently used. The immediate effect of viral integrations may be delayed over time. For instance, in some T cells, the proviral genome may remain silent for many years, evading viral eradication and surviving within the host cell structure; this constitutes a major problem for viral eradication as these cells remain undetected. If ART is abruptly discontinued, silent proviral DNA in long-living T cells may become active and initiate active infection. The type and state of activation of the host cell and subsequent exogenous stimulation are factors that reportedly determine if a cell is productively infected or silently infected after viral fusion.
In actively infected host cells, the cellular polymerase II (Pol II) initiates the transcription of genomic RNA and viral messengers using the integrated provirus as a biological template. Although it takes a short time, proviral transcription includes a series of complex stages involving the viral promoter and multiple cellular transcription factors (Dutilleul et al., 2020). These factors, including nuclear factor kappa B (NF-kB), nuclear factor of activated T cells (NFAT), and the viral transactivator protein Tat, are essential in viral gene expression (Hokello et al., 2021). The influence of these factors on viral infectivity and transcription is still largely unknown. However, recent research studies suggest that Tat binds to a specific sequence of the TAR element. Model studies have reported increased transcription processivity directly linked to this binding and efficient synthesis of long-length HIV transcripts. Not only does Tat increase the success rate of viral transcription, but it also reportedly exerts huge roles in producing an estimated 25 different mRNAs by splicing. These mRNAs are classified into three size classes and include the following:
Rev, Nef, and Tat are essential in the translation and assembly stages. Tat significantly increases viral infectivity by boosting viral transcription and inducing RNA elongation. On the other hand, Rev moves the partially spliced and unspliced viral RNA to the cytoplasm. Nef down-modulates the surface receptors, making the cells more effective in producing infectious viral particles and, most importantly, making infected cells evade the host immune system. The Gag and Gag-Pol precursors initially produced from unspliced RNA are concentrated in lipid rafts of the plasma membrane and are finally processed into structural and enzymatic proteins. Following the interaction of the Env glycoproteins with the structural proteins, two different copies of genomic viral RNAs are recruited. The complex interaction between the different proteins at this stage of HIV infection ultimately results in the formation and assembly of membrane-coated spherical viral particles (Lerner et al., 2022).
HIV infections advance in stages, getting worse with time, especially in cases of poor management. Without adequate viral suppressant therapy or symptomatic management, HIV attains a stage of massive replication characterized by active protein synthesis and the symptoms. At first, the immune response produces a huge volume of antibodies in the initial stage of 'seroconversion.' The most important stages of symptomatic expression as clinical presentation of HIV are often categorized into three different stages – acute HIV infection, chronic HIV infection, and acquired immunodeficiency syndrome (AIDS).
Acute HIV infection is usually characterized by the presence of viremia and the lack of antibodies against the invading virus. In less than six months after infection, anti-HIV antibodies may become detectable, and the presence of viremia may be confirmed by a p24 antigen test or by an HIV RNA test.
Diarrhea, abdominal disturbances, emesis, and nausea constitute the most reported gastrointestinal symptoms at the acute infection stage. Myalgia, joint tenderness, and asymmetric joint swelling are the most reported impairments of the musculoskeletal system. At this stage of infection, the clinical presentation of symptoms may also closely mimic other infections of a viral origin. However, a few distinctive presentations may help medical professionals accurately suspect acute HIV infection. For instance, the first presentation of symptoms, including anemic pallor and lymphadenopathy, may resolve spontaneously without medical intervention. Maculopapular rashes on the proximal extremities (and/or on the trunk) dominate, and the overstressed lymph nodes become discrete and freely mobile. In this case, oral thrush presents as an erythematous mucosa with white exudates. Thrush presentations are commonly found on the soft palate and along the gingival border. In severe cases, thrush might extend to the esophagus, resulting in odynophagia and difficulty swallowing.
Studies aggregating symptomatic presentation at this stage of HIV infection have also independently reported oral hairy leukoplakia presenting as filamentous white lesions found along the lateral borders of the tongue. On the posterior oropharynx, shallow and painful aphthous ulcers may also be present. Oral, genital, and dermal presentation of lesions caused by the herpes simplex virus (HSV) may also be present. In severe cases, perianal and periungual presentation of these lesions may also be noticed. Skin manifestations are commonly reported in severe cases of viral infectivity. Reactivation of herpes zoster virus in previously infected individuals may occur with a general presentation of lesions that extend over several dermatomes. Cutaneous dissemination of lesions may occur. Thrombocytopenia occurring as bleeding gums and easy bruising may be reported, especially in infectious cases where platelet count rapidly falls below 10,000 cells/uL (Shi et al., 2023).
Photophobia, headache, and encephalitis are the common presentations of aseptic meningitis reported during acute infection stages. The involvement of cranial nerves, predominantly nerves V and VII, explains the host of neurologic manifestations reported in acute infection stages. Recent studies have also described acute inflammatory demyelinating polyneuropathy presentations at the early stages of HIV infection. Nerve lesions and myopathy characterized by muscle weakness and laryngeal palsy may also be reported (Shao et al., 2022).
At the chronic stages of HIV infection, the immune response to invading virus cells further depreciates as symptomatic manifestations worsen. Viral load count during this stage progresses slowly as the virus particles replicate slowly in the cellular environment. Depending on the level of viral infectivity, this stage of clinical latency may or may not present with a host of HIV-related symptoms (Ellwanger et al., 2023).
If ART is delayed or not started at this stage of HIV infection, the condition usually progresses to AIDS within ten years or longer. Patients on ART may remain at the chronic infection stage as viral count decreases significantly. A proper ART regimen may eliminate the risk of transmission by crashing the viral load count to a clinically undetectable level. At this level of viral latency, the HIV-positive patient carries no risk of sexual transmission of the virus to an HIV-negative individual.
Chronic HIV infection leads to AIDS in cases of a failed ART regimen or inadequate provision of ART.
AIDS significantly increases the risk of cardiovascular impairment in HIV-positive patients. Symptoms commonly presented in this regard include chest pain, fatigue, dyspnea, and unexplained palpitations (Choi et al., 2021). Clinicians can assess HIV-related cardiovascular complications by examining the jugular veins for distension, checking for peripheral edema, listening to heart murmurs, and checking for signs of pulmonary edema. In most cases, the presenting cardiovascular symptoms in AIDS patients include muffled heart sounds, heart murmurs, pericarditis, point distensions of the jugular veins, and cardiac tamponade secondary to a Mycobacterium tuberculosis infection.
In the pulmonary system, the clinical presentation of AIDS directly influences the rate and manner of airflow. A compromised immune system alters the biological defense of the pulmonary architecture, exposing the upper and lower respiratory tracts to opportunistic infections. Upper respiratory tract infections and bronchitis are the most reported pulmonary complications in these patients. Others of varied levels of expression in the AIDS patient population may include lung cancer, non-Hodgkin's sarcoma, Kaposi sarcoma, sarcoidosis, and emphysema. Clinical evaluations of these symptoms should be prioritized and scheduled daily. Clinicians may assess tripoding, posturing, and other signs of respiratory distress, cyanosis, and tachypnea. Focal adventitious lung sounds may be diagnosed using proper auscultation techniques.
AIDS-related symptoms of the gastrointestinal tract are secondary to opportunistic infections, biological complications, and adverse effects of ART. Lower CD4 counts have been linked to increased susceptibility of the hepatobiliary system, altering normal digestion and upsetting the mechanics of enzyme secretion and action. In addition to this, the daily dosage regimen of ART medications may cause multiple side effects, including steatosis, pancreatitis, and hepatotoxicity (Verma et al., 2022). Other commonly diagnosed gastrointestinal complications of AIDS include esophagitis, herpes simplex infection, and frequent, unexplained bouts of diarrhea secondary to Cryptosporidium infection.
In the central nervous system (CNS), AIDS complications directly impair memory, cognition, and social functioning. Meningitis, cerebral malignancies secondary to immunosuppression, and focal demyelinating lesions are the most commonly presented CNS complications of AIDS (Zenebe et al., 2022).
Depending on the recent CD4 cell count, complaints, as presented, may include frequent headaches, seizures, migraines, cognitive disability, slurred speech, and visual impairments. To properly track symptom development or response to additional symptomatic therapy, clinicians may document the time of symptom onset, severity scale, symptoms' daily frequency, and associated disorders. Reports can also include symptom details on other common CNS presentations, including fevers, neck pain, and any signs of neurologic impairment. Maculopapular rash, morbilliform rash, and oral ulcers are the common symptoms of the dermatologic system in AIDS infection. Others include Kaposi sarcoma, nodules, and vascular neoplasm. In severely immunocompromised patients, dermatologic dissemination of fungal skin infections may also be observed. Clinical observations of dermatological manifestation should prioritize inquiries such as the onset of symptoms, recent skin infections, medical history, allergy profile, and ART side effects (Ramaswami et al., 2021).
A transient reduction in the CD4 cell count is perhaps the most important hallmark of acute HIV infection. During this stage of primary infection, immune system compromise is noticed until the CD4 cell count rebounds to near-normal levels as the primary infection resolves. Although peripheral CD4+ T lymphocyte counts are the first to be impacted, recent research findings suggested a slow decline in circulating and tissue-cased CD4+ T lymphocytes. Based on further research findings, HIV replication and the resultant CD4 cell depletions occur primarily in the gut-associated lymphoid tissues. In these tissues, many memory T lymphocytes are also resident. With increased depletion of gut-associated CD4 cells, the intestinal lining becomes weak, permeable, and overly susceptible to opportunistic infections. Ultimately, the biological immune response is activated as rapid CD4 cell depletion occurs simultaneously in other body systems (Mazzuti et al., 2023).
Several theories have been proposed to explain the mechanics of HIV-related CD4 cell depletion. Many researchers hold that HIV replication may be primarily cytopathogenic – directly invading and destroying healthy cells of the immune system. HIV virion infections may also terminate biological cellular replication by generating incomplete reverse transcripts, leading to an inflammatory reaction and cell death. The HIV virion also negatively impacts the biological functions of the thymus and stem cells in a move to significantly impair the production of new CD4+ T cells (Luo et al., 2022).
The level of CD4 cell depletion has been linked to specific symptomatic presentations in people living with HIV; this explains how the continued suppression of the biological immune defense may precipitate different symptoms in these individuals. The sections below highlight the correlation between symptom presentation and CD4 cell count at different stages of HIV infection.
Mycobacterium tuberculosis
In acute CD4 cell suppression, Mycobacterium tuberculosis may attack the respiratory opportunistic infection documented in HIV-positive patients. The bacilli persist in the system for several years, impairing the alveoli function and causing latent tuberculosis infection. Epidemiological studies in this regard showed that up to 16% of untreated HIV cases have an increased annual risk of active tuberculosis disease; this is a sharp contrast to only 5% in HIV-negative individuals with latent tuberculosis (Gill et al., 2022). Symptom presentation may include fever, unexplained weight loss, chronic cough, dyspnea, fatigue, and spitting of blood. In severe cases of immune compromise, miliary tuberculosis is characterized by the dissemination of bacilli in the bloodstream and subsequent infections in many organ systems.
Coccidioidomycosis-related infection
Coccidioidomycosis-related infections at this level of CD4 depletion are mainly of two types – Coccidioides immitis and Coccidioides posadasii. These microorganisms are found in large deposits in the soil. Contamination with food or water sources may facilitate host-system infections in immunocompromised HIV patients. During infection, the most commonly reported symptomatic presentations include focal pneumonia characterized by fever, pleuritic chest pain, and cough; meningitis characterized by persistent headache, lethargy, and fatigue; positive serology test with no symptomatic presentation; and diffuse pneumonia characterized by hypoxemia, fever, and dyspnea (Agarwal et al., 2022).
Mucocutaneous candidiasis
Candida albicans are considered the causative organism of this infection. Oropharyngeal presentations of candidiasis at this level of CD4 depletion occur as plaque-like lesions with white, creamy appearances in the oral mucosa. Surface distribution of these lesions may extend to the soft palate, esophagus, gums, and tongue surface. In the esophagus, these lesions present with a particular burning sensation, resulting in painful swallowing and discomfort in mastication. Endoscopic examinations may reveal extensions of these white plaque-like presentations down the gut. In females living with HIV, candidiasis infections may precipitate vulvovaginal manifestations characterized by frequent urination, smelly discharges, itching, and mucosal burning sensations. Symptomatic therapy and ART may help relieve these manifestations.
Pneumocystis jiroveci pneumonia (PCP)
The PCP fungus is widely studied in connection to the symptomatic presentation of CD4 depletion in HIV-positive patients. Generally, the most commonly reported manifestations include high fever, dry cough, irregular breathing patterns, and hypoxemia. Chest examinations confirm pulmonary involvement with the development of bilateral, symmetrical infiltrates appearing in a ground glass pattern (Liebenberg et al., 2021).
Histoplasma capsulatum
At this stage of CD4 cell depletion, AIDS is diagnosed. Histoplasma capsulatum infections primarily affect the pulmonary system in conditions characterized by fever, dyspnea, headache, chills, and myalgia. In HIV-positive patients with an impressive response to ART, CD4 cell rebound may lead to a complete resolution of these symptoms. However, in chronic CD4 cell depletion, severe cases of histoplasmosis infections may develop; this is a common case in elderly HIV-positive patients with a rapidly depleting CD4 cell population. Disseminated histoplasmosis fungal clusters in different organ systems through the lymphatic and circulatory system may manifest as unexplained weight loss, fever, lymphadenopathy, ulcers and lesions of the oral and nasal cavity, hepatosplenomegaly, and ulcerative erosions of the gastrointestinal system.
Herpes simplex virus
Clinical examinations such as viral culture, HSV antigen tests, and HSV DNA polymerase chain reaction (PCR) are often recommended to confirm active HSV in HIV patients. These examinations detect even traces of HSV in the cells. Genital lesions are often recommended for typing to distinguish between active infections of both HSV-1 and HSV-2 viruses. If confirmed in HIV-positive patients, HSV infections at this stage of CD4 depletion manifest as oropharyngeal lesions, genital herpes, encephalitis, and eczema herpeticum. In male patients, HSV proctitis characterized by deep, non-healing ulcers is commonly reported.
Cryptosporidiosis
This infection is caused by a protozoon – Cryptosporidium; this microbe affects the cell population along the gastrointestinal tract and the small bowels. In the acute phases of the infection, Cryptosporidium causes several bouts of unexplained diarrhea and severe abdominal pains. Reports of nausea, gastrointestinal disturbance, and frequent vomiting are common. In people with continued CD4 depletion, Cryptosporidium may cause a severe case of extraintestinal cryptosporidiosis characterized by extensive gut ulcerations, perforations, and watery diarrhea. Clinical examinations that detect Cryptosporidium oocytes in the stool or gut tissue samples are required to confirm active Cryptosporidium infection. Active infection can also be confirmed by enzyme-linked immunosorbent assays (ELISA) and immunofluorescence.
Cryptococcus neoformans
A Cryptococcus neoformans infection may manifest as an acute presentation of meningitis or meningoencephalitis. The most common symptoms of these disease states include fever, malaise, headache, and vomiting. As a yeast characterized by a thick, usually drug-resistant capsule, eliminating Cryptococcus neoformans presents a peculiar difficulty in immunocompromised patients. In severe cases, the yeast causes pulmonary cryptococcosis, upsetting the pulmonary systems and prompting the development of symptoms such as dyspnea, chest pain, and cough. Testing from cryptococcal antigen in the cerebrospinal fluid is considered an accurate clinical examination to confirm an active infection; this is particularly important in patients with meningitis or meningoencephalitis. Blood cultures are also useful in the clinical diagnosis of Cryptococcus neoformans.
John Cunningham virus
Microsporidia
These organisms occur in nature as zoonotic or waterborne microbes, harmless in immunocompetent individuals but causing opportunistic infections in HIV-positive patients. Symptomatic manifestation of microsporidiosis depends solely on the causative organism. In active infection caused by Encephalitozoon intestinalis, the most commonly presented symptoms include diarrhea, vomiting, nausea episodes, and superficial keratoconjunctivitis. Encephalitozoon cuniculi causes impairment of the hepatobiliary system, with presenting symptoms ranging from hepatitis to encephalitis. Encephalitozoon hellem, on the other hand, causes sinusitis, breathing difficulties, and prostatic abscesses. As expected, these opportunistic infections are more pronounced in HIV-positive individuals with a pronounced depletion of CD4 cells. Microsporidiosis is detected by light microscopic methods employing stains such as Unitex 2B and Chromotrope CR. Sample collection for microscopy can be done with stool or small bowel biopsy in severe cases of infection.
Mycobacterium avium complex (MAC)
Toxoplasma gondii encephalitis
Toxoplasma gondii is a coccidian protozoan globally distributed in soil samples, water samples, or on the skin surfaces of soil-burrowing animals. This microbe is harmless in immunocompetent humans but constitutes a major health risk in people with a CD4 count of fewer than 50 cells/mm3. The most common clinical presentation of Toxoplasma gondii is focal encephalitis with other symptoms such as headache, altered mental state, motor weakness, muscle weakness, and fatigue. Clinical evaluation of Toxoplasma gondii infection involves the detection of anti-plasma immunoglobulin G antibodies. Imaging investigation may detect cluster lesions, and brain biopsy may provide a definitive biopsy.
Bartonellosis
In HIV-positive patients, Bartonella henselae and Bartonella quintana have been reported as the causative organisms of Bartonellosis. The infectious components from these organisms are spread through the blood, invading soft tissues and forming lesion masses in different tissue organs. Lesions may also appear on the skin as quiet breakouts that populate over time. Symptomatic observations may depend on the specific causative microbe. For instance, Bartonellosis caused by Bartonella quintana has osteomyelitis and endocarditis as its most common symptoms in advanced infection stages. On the other hand, bacillary peliosis hepatitis is considered the most common symptom of Bartonella henselae in the advanced stages of infection.
Pre- and post-exposure prophylaxis regimens are designed to significantly reduce the risk of active primary infection in individuals exposed to HIV. Pre-exposure prophylaxis is used before a potential exposure, and post-exposure prophylaxis provides substantive biological protection against the virus after a possible exposure.
Over the years, HIV testing algorithms have improved. The current recommendations are designed to increase the chances of viral load suppression and also reduce the chances of false positives. The CDC guideline on HIV testing recommends initial screening with an antigen-antibody assay. All positive assay results are further confirmed with a combination immunoassay to differentiate between HIV-1 and HIV-2 infection cases. Detection of a primary HIV infection is considered important to the disease's prognosis and patients' survival. According to the CDC guidelines on acute HIV infection diagnoses, the following scenarios must be considered by clinicians during HIV screening routines.
Rapid diagnosis can also be done using blood samples from a finger stick or from oral fluids; this option provides a testing result within 30 minutes. In cases when finger-stick tests are considered not accurate enough, the popular fourth-generation antigen/antibody tests or NATs are recommended. These tests show a high accuracy rate and can easily detect HIV virion in the acute infection stages. Globally, routine HIV testing campaigns are widely publicized to catch HIV infection cases in the early stages of infection and increase the reach of ART distribution. In Europe and Africa, these campaigns are targeted at population clusters with poor access to primary healthcare, including HIV prevention programs. Injection drug users, men who have sex with men, and prisoners are specifically targeted in these campaigns. In the United States, the United States Prevention Services Task Force (USPSTF) recommends quarterly HIV screening tests for individuals at high risk of contracting the virus and at least once for immunocompetent individuals. In the same vein, the WHO recommends HIV screening and testing for all children and adults presenting for medical care in areas of generalized HIV epidemics.
A complete blood cell count profile has also been incorporated into the HIV screening algorithm in different parts of the globe; this count helps clinicians quickly evaluate patients' risk of leukopenia, anemia, and thrombocytopenia. If the result suggests an active infection, viral and CD4 counts may be ordered. With a low absolute lymphocyte count, the CD4 count is likely low, and the risk of immunosuppression increases. Clinical surveys have consistently linked low lymphocytes and CD4 cell count to an increased risk of opportunistic infections. Confirmatory tests for HIV may be ordered, especially in cases when the differential diagnoses are many. Cardiac biomarkers and an electrocardiogram (EKG) may be ordered in patients with signs suggestive of a cardiac problem. Ultrasound and echocardiography may be ordered in patients with low lymphocyte counts and a strong differential for acute valvular pathology and pericarditis. Chest radiography may also be useful in those presenting with symptoms indicative of pulmonary infections. In patients presenting with metabolic anomalies as a side effect of pre-/post-exposure prophylaxis, a complete metabolic profile may be ordered to obtain baseline renal and hepatic function and also to evaluate the risk of acute HIV infection.
ARTs in this class interrupt viral replication by disrupting the integration of the HIV genome into the host genome. Dolutegravir, a popular ART in this class, has been found to exert superior viral suppression effects compared to other first-line ARTs. Administered once daily in individuals with a confirmed diagnosis of HIV infection, dolutegravir has shown an impressive safety profile and limited drug-drug or drug-food interactions. Raltegravir, another INSTI, has shown comparable efficacy to dolutegravir. Unlike dolutegravir, raltegravir is administered twice daily and also demonstrated an impressive safety profile in HIV-positive patients. Elvitegravir is another commonly prescribed member of this class.
Entry inhibitors exert pharmacological action against the HIV virion by directly disrupting how the virus invades healthy human cells. Drugs in this class of ART act on the cofactors and other entry apparatus explored by the virus. For instance, maraviroc, an entry inhibitor, directly antagonizes the R5 virus strain from binding to the outer membrane of healthy CD4 cells. Before maraviroc is recommended for use in HIV-positive patients, highly technical tests confirm the absence of virus strains using the CXCR4 cofactor for cellular binding. Enfuvirtide, another entry inhibitor, exerts pharmacological action by binding directly to HIV. Enfuvirtide is rarely used in the general population as it is expensive and must be administered parenterally twice daily (Orkin et al., 2022).
Protease enzymatically facilitates virion budding and maturation by cleaving long polypeptide chains from the virion, effectively turning it into an infectious functional protein. Protease inhibitors block virion cell budding and maturation by inhibiting the enzymatic actions of protease. Most guidelines on the use of protease inhibitors prescribe their co-administration with two nucleoside analogs; this combination is considered highly effective in progressively reducing the viral load, improving the survival of CD4-bearing cells. As with integrase strand inhibitors, the liver rapidly metabolizes protease inhibitors. Cobicistat is co-administered with protease inhibitors to inhibit the metabolic pathway for their increased elimination (Gandhi et al., 2023).
This class of ARTs disrupts the viral life cycle by blocking the actions of the reverse transcriptase enzyme. They are designed as analogs of natural nucleosides and nucleotides to be incorporated into viral DNA during transcription. On incorporation, the analogs terminate the further extension of the DNA genome, shutting down its transcription process. Today, NRTIs are included in many three-drug ART therapy regimens in combination with an ART from another class. Globally, only two first-line NRTI-based ART regimens are recommended for use in HIV-positive patients; they are abacavir and lamivudine or tenofovir and emtricitabine.
Zidovudine and stavudine are other nucleoside analogs not currently prescribed in the HIV population. Although these drugs demonstrate potent drug actions against the HIV virion, they have been linked with a few life-threatening side effects that significantly limit their clinical use. Some of the commonly reported side effects of these drugs include anemia, hepatic stenosis, lipoatrophy, lactic acidosis, and neuropathy. In regions of the world with low investment in ART programs, these drugs are still widely used as second-line regimens. Abacavir is another NRTI linked with life-threatening allergies in HIV-positive patients with the HLA-B*5701 allele. Epidemiological surveys have linked abacavir with a high risk of cardiovascular diseases, especially in HIV-positive patients with multiple comorbidities.
Similar to NRTIs, this class of ARTs also inhibits the action of the reverse transcriptase enzyme, although in a different manner. NNRTIs induce a conformational change in the enzyme by actively binding to a region near the active site of the enzyme; this conformational change inactivates the enzyme, truncating the transcription process and reducing viral load in HIV-positive patients. ARTs in this class are safe, potent, and cheaply produced. Efavirenz and nevirapine are perhaps the most widely prescribed ARTs in this class. Although considered safe and widely tolerated, NNRTIs have been linked to a few CNS toxicities (Patel & Zulfiqar, 2022).
Complementary and alternative medicine are care practices not generally considered conventional therapy in HIV management. In addition to the conventional practices of prescribing ARTs in HIV management, other alternative medicine systems are becoming popular in the HIV-positive global community. Herbal medications, osteopathy, homeopathy, acupuncture, and massage are considered the most widely prescribed alternative medicine in this regard (Yunihastuti et al., 2022). Unlike conventional ART regimens, complementary medical practices are designed to offer symptomatic relief and not to reduce viral load.
Homeopathic therapies and Chinese medicine practices, including acupuncture and acupressure, offer improved blood flow and reduce the severity of dyspnea, cardiovascular complications, and renal decline in HIV patients. Supplements such as melatonin, whey protein, and chondroitin help combat unexplained weight loss, bone degeneration, and insomnia. Reflexology also reportedly helps with improved joint movement, decreasing the risk of bone degeneration.
The management of HIV and AIDS is a lifelong process requiring optimum adherence to therapy and continued evaluation of therapy. Complementary medical practices can be combined with conventional clinical care to improve the outcome of therapy. Medical personnel collaboration is essential for tracking therapy outcomes and side effects. In the long run, the primary aim of HIV therapy is the reduction of viral load while improving the population of CD4-bearing cells.
CEUFast, Inc. is committed to furthering diversity, equity, and inclusion (DEI). While reflecting on this course content, CEUFast, Inc. would like you to consider your individual perspective and question your own biases. Remember, implicit bias is a form of bias that impacts our practice as healthcare professionals. Implicit bias occurs when we have automatic prejudices, judgments, and/or a general attitude towards a person or a group of people based on associated stereotypes we have formed over time. These automatic thoughts occur without our conscious knowledge and without our intentional desire to discriminate. The concern with implicit bias is that this can impact our actions and decisions with our workplace leadership, colleagues, and even our patients. While it is our universal goal to treat everyone equally, our implicit biases can influence our interactions, assessments, communication, prioritization, and decision-making concerning patients, which can ultimately adversely impact health outcomes. It is important to keep this in mind in order to intentionally work to self-identify our own risk areas where our implicit biases might influence our behaviors. Together, we can cease perpetuating stereotypes and remind each other to remain mindful to help avoid reacting according to biases that are contrary to our conscious beliefs and values.