Latent TB Testing

Latent tuberculosis (TB) means someone has TB bacteria in their body, but the bacteria are “asleep”. They do not feel unwell, do not have symptoms, and cannot pass TB to other people while it is latent. However, latent TB can sometimes become active TB, especially if someone’s immune system becomes weaker. Active TB can make people seriously unwell and can spread to others.

Latent TB testing is usually a simple blood test. It checks whether someone has been infected with TB bacteria in the past. The test is important because latent TB cannot be detected by symptoms alone.

The NHS latent TB testing and treatment programme focuses on people who have recently entered the UK from countries with higher TB rates, particularly people aged 16 to 35 who were born in, or spent more than six months in, a high TB incidence country and entered the UK within the last five years.

Why testing matters?

Testing helps to:

• Find TB early, before it causes illness.
• Offer treatment to stop latent TB becoming active TB.
• Protect family, friends and the wider community by reducing future spread.
• Support people who may be at higher risk, including those who have lived in countries where TB is more common.

Latent TB testing is an important preventative health check. It helps protect your health and supports wider public health by reducing the risk of TB developing and spreading in the future.

If your GP practice offers you a latent TB test, please book and attend your appointment.

What happens if the test is positive?

A positive test does not mean someone has active TB. Further checks may be needed to make sure there is no active infection. If it is latent TB, treatment is usually offered with antibiotics to greatly reduce the risk of it becoming active TB in the future.