Until 2005, school children in the UK and most other European countries were given a vaccination against TB, called BCG. However, this vaccination does not offer complete protection against TB, and there have been cases of people who received the BCG vaccination as a child developing TB. Since 2005, the UK has had a policy of targeting use of this vaccine. Those recommended for vaccination include:

• All children living in areas where there is a lot of TB.
• Children whose parents or grandparents were born in countries where there is a lot of TB.
• Recent immigrants from countries where there is a lot of TB.

People with HIV should not be given the BCG injection as it is a live vaccine and can cause a TB-like illness.

One of the best ways of preventing TB in people with HIV is to improve the immune system. Treatment with combinations of effective anti-HIV drugs boosts the immune system, enabling it to fight TB and other infections.

People with latent TB are sometimes given an anti-TB drug or drugs to prevent the TB becoming active. People who have been in close contact with people who have TB may also be given an anti-TB drug to prevent them becoming infected.

The drug normally used is called isoniazid, which is given for at least six months. Sometimes a combination of another drug, rifampicin, with isoniazid can be given for four months. It is recommended that HIV-positive people who come from communities that have high levels of TB, including people from Africa and those from the Indian sub-continent, are given this prophylactic treatment if their Mantoux test was positive. It is also recommended that HIV-positive people who have been in close contact with people who have active TB should receive this treatment.  Talk to your doctor or someone else at your HIV clinic if you are concerned this might apply to you.

Isoniazid can cause side-effects and interact with some anti-HIV medicines, particularly ddI (didanosine, Videx) and d4T (stavudine, Zerit). You will need to discuss your HIV treatment with your doctor if you are on either of these drugs.

Isoniazid can also be harmful to the liver, and you will have your liver's function monitored closely as long as you are taking isoniazid.

Eating well, getting an adequate amount of sleep and living in dry, well-ventilated housing will help you avoid infection with TB or stay well if you have been exposed to it or have latent TB. The booklet Nutrition, which is also produced by NAM in this series, gives some tips on healthy eating.

If you cannot afford to eat properly or have housing problems, it is important that you find help and advice.  Talk to your doctor or someone else at your clinic, or if you have a social worker or an advice worker, ask them to help you.  If you are not sure who to talk to, you can contact THT Direct on 0845 12 21 200, which is a helpline for people living with HIV.  They can help you look at your options and put you in contact with somebody who can provide you with support and help.

If you come into contact with somebody with TB, such as a family member, housemate or friend, then you should go to your HIV clinic as soon as possible for tests to see if you have been infected.