In 1993, the World Health Organization (WHO) declared
tuberculosis a global emergency. Tuberculosis (TB) is
responsible for more deaths than any other infectious
disease. Every year around 8 million people are infected with
TB around the world, and 3 million people die from
TB.
TB is a disease caused by an infection with a
bacterium called Mycobacterium tuberculosis. TB most
commonly affects the lungs. But it can spread via blood from
the lungs to all organs in the body. This means that TB can
develop in the covering of the lungs (the pleura), lymph nodes,
brain, skin, bones, urinary tract, sexual organs and the
intestines.
TB is more common in areas of the world where poverty,
malnutrition, poor general health and social disruption are
present. It is also seen in people whose immunity is reduced,
for example in people with HIV infection. TB is especially
common in sub-Saharan Africa, where the proportion of people who
are HIV positive is exceptionally high.
In the UK, the number of TB cases is
rising. People who are alcoholics, HIV positive, have
recently settled in the UK and healthcare workers are at increased
risk.
Today, treatment involves three or four
different kinds of antituberculous drugs given in combination over
six to nine months.
The MRC Clinical Trials Unit is participating
in two multi-centre international clinical trials, REMoxTB and
RIFAQUIN, which are both investigating the possibility of
shortening chemotherapy from 6 to 4 months. Study C which was
completed recently addressed the question whether giving a combined
formulation of drugs is as effective as giving the drugs
separately. Planning is under way for STREAM, a trial in MDR-TB
(multi-drug resistant TB).
