What is tuberculosis?

Tuberculosis – or TB – is a disease caused by a germ called the tubercle bacterium or Mycobacterium tuberculosis.

It usually affects the lungs but can affect other parts of the body. Only some people infected with the TB germ go on to develop TB disease.

TB is curable with a full course of treatment.

How do you catch it?

The TB germ is usually spread in the air. It is caught from another person who has TB of the lungs. The germ gets into the air when that person coughs or sneezes.

Only some people with TB in the lungs are infectious to other people. These cases are called sputum smear positive or open TB. Even then, you need close and prolonged contact with the infectious person to be at risk of being infected. Sputum smear positive cases stop being infectious after treatment lasting a couple of weeks.

Can anyone get it?

Anyone can get TB but it is difficult to catch. You are most at risk if someone living in the same house as you catches the disease or a close friend has the disease.

What are the symptoms?

TB disease develops slowly in the body and usually takes several months for symptoms to appear.

Any of these symptoms may suggest TB disease:

• fever and night sweats
• persistent cough lasting more than four weeks
• losing weight without dieting
• blood in the sputum (phlegm or spit).

How is it treated?

TB can be cured by taking a course of antibiotics for about six months.

What should I do if I think I might have TB?

Visit your GP or contact us.

What is the difference between being infected with the TB germ and having TB disease?

The majority of exposed people will kill off inhaled TB germs. Sometimes, not all of the germs are destroyed and the person can become infected. However, in most infected people, the body is able to contain the infection and stop the germs from growing. The germs become inactive, but they remain alive in the body and can become active later.

Most people who have been infected with the TB germ will never develop TB disease. In these people, the TB bacteria remain inactive for a lifetime without causing disease but in other people the bacteria may become active and cause TB disease later.

People infected by the TB germ without TB disease:

• have no symptoms
• don’t feel sick
• cannot spread TB to others
• usually have a positive skin test reaction
• can develop TB disease later in life.

What is done after exposure to someone with TB?

When someone is diagnosed with TB, a team of specialist healthcare professionals will assess the risk of infection to others and contact tracing will be used to identify others who may have been infected.

If you are identified as a contact at risk from TB, you will routinely be invited for screening. Tests used for screening include an interferon gamma release assay (IGRA) blood test, Mantoux skin test or chest x-ray.

People who have evidence of TB infection, found from any of these tests, or those who are unwell, will be referred to a specialist for further assessment and possible treatment.

Can TB be prevented?

Yes it can. Most important is early detection, especially of infectious cases, and complete treatment of those cases to prevent spread. In some high-risk groups, BCG vaccination can offer some protection against TB but overall BCG vaccination plays a limited role in TB control.

What is the interferon gamma release assay test (IGRA)?

This is a blood test that can be used to help the diagnosis of TB. It may be used in the diagnosis of TB infection or TB disease.

The IGRA test can be more accurate than the Mantoux skin test and will help determine whether you have been infected with TB and may need treatment. The test involves taking a single specimen of blood. Results will be available one-to-three weeks later.

A positive result means infection with TB is likely. A negative result means infection with TB is unlikely.

There are no significant risks associated with the test, apart from the minor discomfort of a blood test.