HIV and tuberculosis (TB) epidemics are closely connected. The two diseases fuel one another in countries like South Africa, where large percentages of people are infected with HIV. Worldwide, about one in three HIV-positive people are also infected (or co-infected) with TB, and TB is the leading killer of people with HIV.
TB is spread by germs travelling through the air, usually when a person with TB disease coughs or sneezes. You can be infected with TB without having any symptoms – this is called latent TB. People with latent TB are not physically sick and cannot transmit the disease. If you develop TB symptoms, it means you now experience the TB disease (also called active TB) and can infect other people with TB. If left untreated, the TB disease can lead to death.
Anyone can be infected with TB, and in fact about one-third of the world’s population has latent TB. But TB is especially dangerous for people with weak immune systems, including those infected with HIV.
People co-infected with HIV and TB are much more likely to develop active tuberculosis – and to become sick more quickly – than those infected with TB only. This means that TB spreads faster in parts of the world where HIV is prevalent. TB is also more difficult to diagnose in people infected with HIV.
Unlike HIV, TB disease is almost always curable. Treatment usually consists of a combination of drugs and must be taken every day for several months. You must take the medication properly and consistently, without missing any doses. Otherwise the disease may become resistant to treatment.