 Tuberculosis
(abbreviated as TB for Tubercle Bacillus) is a common
and deadly infectious disease caused by the bacterium
Mycobacterium tuberculosis, which most commonly affects
the lungs (pulmonary TB) but can also affect the central
nervous system, lymphatic system, circulatory system,
genitourinary system, bones and joints.
Tuberculosis is one of the deadliest and common major
infectious diseases. As of 2004, 14.6 million
people have active TB disease with nine
million new cases of the disease and nearly
two million deaths, mostly in developing
countries. However, developing countries are not the
only places with tuberculosis. There is a rising number
of people in the developed world who contract tuberculosis
because they have compromised immune systems, typically
as a result of immunosupressive drugs or HIV/AIDS. These
people are at particular risk of tuberculosis infection
and active tuberculosis disease.
Most of those infected (90%) have asymptomatic latent
TB infection (LTBI). There is a 10% lifetime chance
that LTBI will progress to TB disease which, if left
untreated, will kill more than 50% of its victims. TB
is one of the top four infectious killing diseases in
the world: TB kills 1.7 million, and malaria
kills 2-3 million. |
