Tuberculosis (TB) in children

Tuberculosis (TB) is a serious bacterial infection. This page has information on tuberculosis in children.


What is tuberculosis (TB)?

Tuberculosis (TB) is a serious bacterial infection. You can catch it from other people by breathing in tiny infectious particles of TB bacteria. Children usually catch it from close contact with an adult who is coughing and infectious.

TB usually affects the lungs, but it can affect other parts of the body too. Other parts of the body tuberculosis may affect include the

  • bones (such as the spine)
  • brain
  • lymph glands
  • abdomen.

What causes tuberculosis (TB)?

TB is caused by breathing in TB bacteria, called Mycobacterium tuberculosis. Usually, the immune system can fight off these bacteria, but sometimes they make people ill.

Active TB and latent TB

When people get ill from infection with TB bacteria, this is called active TB.

For most people, when they breathe in TB bacteria, the germs enter the body and stay there. This is called latent TB. There are no symptoms, and a person with latent TB is not infectious. That’s because the immune system can control the infection.

Over time the bacteria can sometimes escape the control of the immune system. The latent TB then becomes active TB.


Who is at risk of tuberculosis (TB)?

There are two different sorts of risk for TB:

  • risk of getting infected
  • risk of getting ill.

To get infected with TB bacteria, you would need to be in close contact with someone who has active TB. TB is rare in the UK, so the risk of getting infected is quite low. There are some countries where it’s more common, and the risk of infection is higher in these countries.

The risk of getting ill from TB infection depends on how well your immune system works. Babies, toddlers and young children are more at risk of getting ill from TB than healthy adults. This is probably because their immune systems are not fully developed.

BCG vaccination

The BCG vaccination offers some protection against TB, but it’s not given routinely on the NHS. It’s only offered to people at higher risk of developing TB.

Babies born in the UK may be offered BCG vaccination if:

  • they live in an area with high rates of TB
  • they have a parent or grandparent from a country with high rates of TB.

What are the symptoms of tuberculosis (TB) in children?

Children with latent TB will have no symptoms.

In the early stage of active TB, children may also have no symptoms. Symptoms of active TB in children may include:

  • a cough that does not get better after 3 weeks
  • fever (high temperature) that cannot be explained by other causes
  • weight loss, or difficulty putting weight on
  • feeling generally unwell
  • night sweats.

Other symptoms may affect the parts of the body where the TB infection has spread. For example, a child with TB affecting the brain may have symptoms of meningitis.


How is tuberculosis (TB) diagnosed?

It can be difficult to diagnose TB in children. This is because children develop a different type of TB from adults.

In children, there are far fewer TB bacteria than in adults. It’s also harder for children to cough up mucus. That means it’s difficult to detect the bacteria in a sample from the lungs or stomach.  

TB is now rare in children and lots of the signs of TB can also be signs of other diseases.  

TB in the lungs

If the doctor thinks your child may have TB in their lungs, they will have tests. Your child may be referred to a TB specialist to do these tests. Tests for TB in the lungs may include:

  • a chest X-ray
  • a blood test
  • a skin test
  • collecting samples from the lungs or stomach

TB outside the lungs

Sometimes, TB bacteria can spread to other parts of the body. If the doctor thinks your child may have TB in another part of their body, tests may include:

  • a blood test
  • scans in that part of the body
  • taking samples of fluid from the body with a needle, and testing them for TB bacteria
  • biopsy. A surgeon makes a small cut and removes some tissue under general anaesthetic. The tissue is tested for TB bacteria.

Latent TB

If your child has been in contact with people who have TB, doctors might test them for latent TB. Latent TB isn’t usually infectious and doesn’t usually cause any symptoms. But in some cases, latent TB can become active.

Tests for latent TB may include:

  • a skin test
  • a blood test
  • a chest X-ray.

How is tuberculosis (TB) treated in children?

TB is treated with a combination of antibiotics, to kill the TB bacteria. Your child will see specialist TB doctors and nurses.

If your child has active TB, they will need to take antibiotics for at least 6 months. It is very important to make sure they take the full course of antibiotics, even if they seem to get better. Stopping treatment early could allow the TB bacteria to come back.

If your child has latent TB, they will still need antibiotics, but they may take a lower dose for a shorter time.


Preventing the spread of infection

Children diagnosed with active TB are usually not infectious. However, they should stay away from school or nursery until a health care professional says they are definitely not infectious. This is usually after 2 weeks of antibiotic treatment for TB.

Parents and family members can prevent the spread of infection by:

  • encouraging everyone to wash their hands regularly
  • disposing of used tissues in a sealed plastic bag
  • keeping the windows open at home, where possible.

Adults with active TB in the lungs can spread it easily. Children usually catch TB from an infectious adult.

Let doctors know if someone in your close family has been unwell for some time, especially if they are coughing and losing weight. They will need to have tests to diagnose TB. Before TB is diagnosed, they should not visit children in hospital or go with them to outpatient appointments.  If TB is confirmed, they should wait until their own specialist TB doctors and nurses say they are no longer infectious.


Where can I find more information and support?

We have more information about tuberculosis in adults.

The TB Action Group is run by the charity TB Alert. It provides support for people affected by TB in the UK.

We use your comments to improve our information. We cannot reply to comments left on this form. If you have health concerns or need clinical advice, call our helpline on 03000 030 555 between 9am and 5pm on a weekday or email them.

Last medically reviewed: September 2019. Due for review: September 2022

This information uses the best available medical evidence and was produced with the support of people living with lung conditions. Find out how we produce our information. If you’d like to see our references get in touch.