Tuberculosis (TB)

What is tuberculosis (TB)?

Tuberculosis (TB) is a bacterial infectious disease cause by infection with Mycobacterium tuberculosis complex (M. tuberculosis, M. africanum or M. bovis). TB is transmitted through inhaling tiny droplets from sneezes or coughs of an infected person. TB mainly affects the lungs, but can affect other parts of the body, including the lymph nodes (glands), kidneys, tummy (abdomen), gut, bones, nervous system and, rarely, the brain.

There are two types of TB-related conditions: latent TB infection (LTBI) and TB disease. People with latent TB infection are infected with M. Tuberculosis but do not have any symptoms of disease; the TB bacteria can remain inactive for a lifetime without causing TB disease. But in people with a weak immune system, the bacteria become active, multiply, and therefore cause TB disease.

For those with latent TB who are aged 65 or under, treatment with antibiotics is usually recommended. However, the antibiotics used to treat TB can cause liver damage in older adults. Although uncommon in the UK there are strains of TB that are resistant to two or more antibiotics. This is known as multidrug-resistant TB.

Find out more about TB on the NHS website.

Testing

Individuals may need to be tested for TB if they have been in close contact with someone known to have active TB disease or have recently spent time in a country where TB levels are high. People who have just moved to a country where TB is common should be given information and advice about the need for testing.

Prevention

The BCG vaccination protects against TB and is recommended on the NHS for babies who are at high risk, following SCID screening. Children and adults under the age of 35 years who are considered to be at-risk of catching TB or have been exposed to TB are offered the BCG vaccination.

To see who is eligible for the BCG vaccination, refer to 'Tuberculosis: the green book, chapter 32' on GOV.UK website.

Page last updated: 30 January 2023