How do I know if I have latent TB?
Latent TB does not have any symptoms. The only way to find out if you have latent TB bacteria in your body is to have a blood test or skin test.
I have been invited for a TB test. What should I do?
You have been invited for a latent TB test because you are at increased risk of becoming ill with TB. There is no need to be worried. Latent TB can be treated before it can cause active TB, and all testing and treatment for TB is free and confidential for everyone.
Why might I need to be tested for latent TB?
There are some reasons why you may be more likely to have latent TB or have a higher risk of going on to develop active TB if you do already have latent TB:
If you know someone who has or has had TB
You may be asked to take a test for TB if you have spent a lot of time with someone who has TB – it could be a family member, friend or colleague. This is called contact tracing. Read our patient information leaflet on contact tracing for more information.
If you have settled in England in the last five years from a country where TB is more common
If you have settled in the UK in the last five years, and came from a country where TB is more common (in dark blue on the map), you may receive an invitation for latent TB testing through your GP surgery. You can also ask your GP for a test if you have not received an invitation. If you are not yet registered with a GP use the service finder on the NHS website.
This test is different to the x-ray that you may have had as part of your visa application process, which only looked for active TB. Having a test for latent TB in England does not affect you right to be in this country, whether or not the test shows you have latent TB or even if you have developed active TB since you arrived.
For occupations where the risks from TB are increased
It is likely that you will be offered a test for latent TB before starting work in a health or social care setting. This will check whether or not you have been in contact with TB before starting the job and you will be offered preventive treatment if you need it. You may also be tested routinely during your time in the post as you role may put you at increased risk of exposure to TB.
If you have a health condition or take medication that affects your immune system
You are more at risk of developing active TB if you have another health condition such as diabetes or HIV, or if you are taking medication which dampens your immune system. For this reason you may be offered a test to make sure you do not have any latent TB bacteria in your body. If you do, then you will be offered treatment which will prevent them becoming a problem.
What is my risk of developing active TB if I do have latent TB?
Without treatment for latent TB, there is about a 1 in 10 chance that you will develop active TB in your lifetime. You are more likely to develop active TB in the first five years after you breathe in TB bacteria, though you may not know when that happened.
Why should I be tested for TB if I do not feel ill?
Latent TB does not have any symptoms, but it has the potential to make you ill. Prevention is better than cure so it is a good idea to get tested for latent TB so that you can take treatment, if necessary, to protect your health in the future.
I have had the BCG vaccination. Surely I don’t need to worry about TB?
You can still develop latent or active TB after you have the BCG vaccination. This is because the vaccination offers limited protection and only for up to 15 years.
I have received a clear chest x-ray, does this mean I do not have latent TB?
TB chest x-rays can only detect active TB in the lungs. This means that you may have latent TB bacteria in your body, even if you have had a clear chest x-ray.
I’m worried that I may have latent TB. What can I do?
If you are worried that you may have latent TB for any reason, but you have not been invited for a test, phone your local chest clinic or GP. They will arrange an appointment for you if necessary. You can find out where your local GP is and how to register by visiting the NHS Choices website you may also find this leaflet useful for advice on accessing GP services in England.
