TB

Tuberculosis (TB) is a contagious disease. Like the common cold, it spreads through the air. Only people who are sick with TB in the lungs is contagious. When infectious people cough, sneeze, talk or spit, they propel TB germs, known as bacilli, into the air. A person needs only to inhale a few of these to be infected.

Left untreated, each person with active TB disease infect on average between 10 and 15 people each year. But people infected with TB bacilli will not necessarily become sick with the disease. The immune system "walls off" the TB bacilli, which is protected by a thick waxy coat, can lie dormant for years. When the immune system is weakened, the chances of getting sick are greater.