HIV, AIDS, and Tuberculosis
HIV and the Types of Tuberculosis Infection
There are two types of tuberculosis infection, latent and active.
- If you have a latent infection, the germs remain in your body, but don't cause symptoms.
- If your immune system is weak, the germs can multiply and become active, causing symptoms and disease.
Active disease is more likely if you have HIV, especially if your CD4 count is under 200. (CD4 cells are a type of immune system cell.) However, active tuberculosis can happen no matter what your CD4 level is. If you are infected with both HIV and TB, you are at least 10 times more likely to develop active TB than someone without HIV. If you have both infections, you have AIDS (acquired immunodeficiency syndrome), a more advanced stage of HIV.
These are other factors that can increase your risk for active tuberculosis:
- Poor nutrition
- Alcohol or injection drug use
- Being young (less than 5 years old), old (older than 65)
- Being a person of color
HIV and the Symptoms of Tuberculosis
These are common signs and symptoms of tuberculosis:
Diagnosing Tuberculosis With HIV
As soon as you know you have HIV, get a tuberculin skin test (TST). The test involves injecting a small amount of fluid with a TB protein under the skin on your arm. After two or three days, a health care provider checks for swelling at the site of the injection, which is a sign of tuberculosis infection. An alternative is to have one of two approved blood tests collectively called interferon-gamma release assays or IGRAs.
It can be difficult to diagnose tuberculosis for these reasons:
- If you've recently been infected with tuberculosis or if your immune system is very damaged, you may not test positive but still be infected.
- You may test positive, but have a related bacterial infection, not tuberculosis. You may need to have other tests to confirm whether you have active TB.