A disease of the past?

Tuberculosis (TB) is caused by a  bacterium called Mycobacterium tuberculosis and has been causing illness and death in people for thousands of years. Symptoms of TB include cough, fever, night sweats, and rapid weight loss – the disease used to be called "consumption" because of this. TB is still one of the most common causes of death worldwide, mainly affecting the poor, young adults, the elderly, and people who have been weakened by other diseases or by not having enough to eat.

The number of cases of TB fell dramatically in countries like the UK in the middle of the 20^th century thanks to improved standards of living, better general health, effective anti-TB drugs, and TB vaccination programmes. In fact, progress against the disease was so successful that, by the 1980s, many countries such as the UK and USA became confident that they could eradicate TB.

But this was too optimistic, and the number of cases of TB has increased worldwide, partly because of HIV. TB and HIV are seen as the major threats to world health in the 21st century.

TB is an AIDS-defining illness. Worldwide, TB is now the most common cause of death among people with HIV and is the most common AIDS-defining illness in the UK.