Once the TB bacteria reach the lungs, one of three things occurs3, 4:
- The patient may completely clear the bacteria, and no infection develops
- The patient may develop an active infection, primary TB
- The body’s immune system may contain the TB bacteria, causing a chronic infection that shows no symptoms, latent TB
Latent TB is the most common of these three possibilities in the U.S.3,4 Approximately 5-10% of the people who have latent TB will eventually develop active TB.4 In areas where TB is common in the community and healthcare resources are poor, primary TB is prevalent.
Primary TB happens in about 5% of all cases of infection. It typically happens to children and people with a compromised immune system. Children who are <1 year of age have approximately a 50% chance of developing primary TB, and because of the immature immune system, infants and children are quite susceptible to TB spreading to other body systems.
Tuberculosis infections, latent and primary, can be easily treated. TB can develop to be multidrug-resistant tuberculosis. This means that bacteria can no longer be killed by the common drugs used to treat TB.
The immune system does not produce long-lasting immunity against TB. Another infection and active disease can occur even if the bacteria from a previous infection were cleared.
Tuberculosis can spread through other body systems and cause non-pulmonary infections. This is more likely in children and people who are infected with HIV. Non-pulmonary TB infections occur in 10%-40% of patients. Non-pulmonary TB infections may involve the following body systems3:
- Lymph nodes
- Genito-urinary tract
- Bones and joints
There may be questions on forms you complete to help the RN assess the patient. One question may be, “have you been out of the country recently?” Other questions are checking for the following common signs and symptoms of TB.
- Cough for longer than two to three weeks
- Night sweats
- Weight loss
These symptoms can be caused by many infections or medical conditions. A patient with TB may not have these symptoms or only mild symptoms.