World Tuberculosis Day- March 24

World Tuberculosis Day, falling on March 24 each year, is designed to build public awareness about the global epidemic of tuberculosis and efforts to eliminate the disease. Today tuberculosis causes the deaths of about 1.7 million people each year, mostly in the Third World.

March 24 commemorates the day in 1882 when Dr Robert Koch astounded the scientific community by announcing that he had discovered the cause of tuberculosis, the TB bacillus. At the time of Koch's announcement in Berlin, TB was raging through Europe  and the Americas, causing the death of one out of every seven people. Koch's discovery opened the way toward diagnosing and curing tuberculosis.

Tuberculosis (TB) is one of the most common infections in the world. About 2 billion people are infected with TB and nearly 3 million people are killed by it each year. In Canada, there are about 1,600 new cases of TB every year.

The bacterium that causes TB is called Mycobacterium tuberculosis. Someone can become infected and yet not have any symptoms of the active disease - this is called inactive TB.

For someone with a healthy immune system, there's only a 10% lifetime chance of the TB bacteria reactivating and causing the active symptoms of TB. If the immune system has been weakened because of HIV (human immunodeficiency virus) or other illnesses, the risk of moving from an inactive infection to an active symptomatic disease increases to 10% per year.

Babies, preschool children, and seniors are also at greater risk due to weaker immune systems.

Causes of Tuberculosis

Only people who have active TB infections can spread the TB bacteria. Coughing, sneezing, even talking can release the bacteria into the surrounding air, and people breathing this air can then become infected. This is more likely to happen if you're living in close quarters with someone who has TB or if a room isn't well ventilated.

Once a person is infected, the bacteria will settle in the air sacs and passages of the lungs and, in most cases, will be contained by the immune system.