Introduction

Tuberculosis (TB), a chronic bacterial infection, causes more deaths worldwide than any other infectious disease. During the 19th Century, up to 25 per cent of deaths in Europe were caused by this disease. The death toll began to fall as living standards improved at the start of the 20th Century, and from the 1940s effective medicines were developed. However, there are now more people in the world with TB than there were in 1950. The disease is more common in areas of the world where poverty, malnutrition, poor general health and social disruption are present. TB is spread through the air and usually infects the lungs, although other organs are sometimes involved. Some 2 billion people - one-third of the world's population - are infected with the TB organism, mycobacterium tuberculosis, and three million individuals will die this year from this disease - mainly in less developed countries. Each year, 8 million people worldwide develop active TB and 3 million die.

The number of TB cases is again rising in the UK. People with HIV, alcoholics, some recent immigrants and healthcare workers are at increased risk. The disease is most frequently found in places such as hostels for the homeless, prisons, and centres for immigrants arriving from areas with high rates of HIV infection or insufficient health provision.