What is TB? How does it spread?
Q: What is TB? How does it spread? How is it treated?
A: Tuberculosis (TB) is a contagious lung disease that spreads through the air. When people with the disease cough, sneeze, talk or spit, they propel TB germs, known as bacilli, into the air. Only a small number of the bacilli need to be inhaled to cause an infection. However, not all people infected with TB bacilli will become sick. The immune system either kills the germs, or "walls off" the TB bacilli where they can lie dormant for years. Failure of the immune system to control infection with TB bacilli leads to active disease, when TB bacilli multiply and cause damage in the body. Left untreated, each person with infectious TB will spread the germs to about 10 to 15 people every year.
- Someone in the world is newly infected with TB bacilli every second.
- Overall, one third of the world's population is currently infected with TB.
- 5% to 10% of people who are infected with TB become actively sick.
When a person with infectious TB is identified (using a microscope to look for bacilli in a sample of a person's sputum), a full course of the correct dosage of anti-TB medicines should be started, with support of health and community workers or trained volunteers. The most common anti-TB medicines are isoniazid, rifampicin, pyrazinamide and ethambutol.
Supervised treatment helps to ensure that an infected person completes the course of medicine to cure TB and prevent its further spread. Treatment must be continued regularly and uninterrupted for six to eight months. The internationally recommended approach to TB control is DOTS, which is a cost-effective public health strategy to identify and cure TB patients. The approach will prevent millions of TB cases and deaths over the coming decade.