Frequentl y asked questions about Tuberculosis and HI V What i s tuberculosis (TB)? Tuberculosis is a bac t er ial disea se caused b y Mycobacterium tuberculosis. TB disease usually attacks the lungs, however it can also affect almost any part of the body. One third of the world’s population is infected with Mycobacterium tuberculosis but very few of these people actually dev elop tuber culosis disease. Tu b er cu lo u s i n f ec t io n occurs when a person breathes in the tubercle bacilli and it lives dormant ly in t he lung. P eople with tuberculous infection do not usually feel ill as a result of their infection—and such cases are known as silent or latent infections. When TB infection becomes active, usually as a result of something that weakens the body’s immune system, such as malnutrition, HIV or excessive alcohol consumption, the symptoms can be a cough that lasts for more than two or three weeks, weight loss, loss of appetite, fever, night sweats and coughing up blood. Mycobacterium tuberculosis is also known as tubercle bacilli (because they cause lesions called tubercles). How is TB spread? TB is sp r ea d f r om an in f ec t io us person w h o is coug h in g, t o an ot h er person t h roug h t he air. Like the common cold, TB is spread through aerosolized droplets after infected people cough, sneeze or even speak. People nearby, if exposed long enough, may breathe in bacteria in t he droplets and become infected. People with TB disease of the lungs are most likely to spread bacteria to those with whom they spend time every day— including family members, friends and colleagues. After a person with a healthy immune system breathes in TB bacteria, he or she will have 10% lifetime chance of developing TB (compared to a person living with HIV who has a 10% chance of developing TB each year). If a person's immune system is compromised or becomes compromised, however, the bacteria will begin to multiply. From the lungs, bacteria can move through the blood to other parts of the body, such as the kidney, spine and brain. Is TB tr eatable? Yes. TB can be cu r ed, includin g in people li v ing with HIV . The t reatmen t uses a combination of powerful antibiotics over a long period (at least six months) to attack the bacteria and ensure their eradication. It is important that people who have the disease are identified at the earliest possible stage, so that they can receive proper treatment, contacts can be traced for investigation of TB, and measures can be taken to minimize the risk to others. It is very important that the complete course of all prescribed medicines is completed otherwise there is a risk that the TB bacteria become resistant to the drugs. Some strains of TB bacteria have now acquired resistance to one or more of the antibiotics commonly used to treat them; these are known as drug-resistant strains. Tr ea t ment for t hese in f e ct ions is much longer and much more expensive.
