In the UK, it's one of the most common AIDS-defining illnesses. With the right treatment and care, however, it can be cured.
Will TB make me ill?
Some people become ill soon after they are infected with TB. This is called active TB.
However, people can also have latent TB. This is sometimes called dormant TB and it means that TB is present in the body but not causing illness. It can become active again at a later stage. Sometimes, people don’t develop symptoms until many years after infection with TB.
Usually, people have TB in their lungs (called pulmonary TB), but it can affect other parts of the body, such as the bones or kidneys.
You could be at greater risk of developing TB if you come from a part of the world where TB is more common (parts of Africa and Asia, for example), if you spend a lot of time with someone with active TB, or if you’re in poor health.
How can I avoid getting TB?
There is a vaccine against TB, called a BCG. HIV positive people should not be given this as it’s a live vaccine – meaning it uses a weakened form of the bacteria, and can cause a TB-like illness.
If you’re HIV positive and have latent TB, your clinic may recommend a course of TB prophylaxis to reduce the risk that you’ll develop active TB.
The best ways to prevent TB if you have HIV is to:
- Avoid contact with people who have active lung TB until they’re no longer infectious.
- See your doctor as soon as possible if you’re exposed to someone with TB.
- Ensure you have a strong immune system by having a healthy balanced diet, getting enough sleep and not taking recreational drugs or too much alcohol
- Maintain your immune system by taking your HIV medication.
What are the symptoms of TB?
TB usually affects the lungs. A common symptom of TB is a cough that lasts several weeks or longer and that produces phlegm (mucus or sputum), which can be bloody. Other symptoms include:
- high temperature
- night sweats
- weight loss
- shortness of breath
- chest pain.
The standard test to determine if the symptoms are a TB infection is a chest X-ray. Samples of sputum will also be tested to determine if the TB is active and the carrier is infectious.
If doctors are having difficulty finding out the cause of the illness, they may do a bronchoscopy (putting a tube with a camera through the nose into the lungs) or a biopsy (taking a sample of tissue from the lungs). These procedures are performed under an anaesthetic.
In some cases, TB can spread into other parts of the body: lymph nodes, the gut, the spine, the liver or even the brain. This is more common in people whose immune system is very weakened.
There are also tests for latent TB, which is more likely to develop from active TB in people who also have HIV, especially if they have a low CD4 count or are not on HIV treatment.
How is TB transmitted?
TB is normally passed on to other people when someone with active TB coughs or sneezes, in the same way a cold is spread. However, TB is not as easily passed on as a cold. You need to spend a lot of time with the infected person to be at risk of getting TB – for example, living in the same house with them.
People with latent TB who are not sick are not infectious. Only people with active TB in their lungs or throat are infectious.
If you’re HIV positive and have latent TB, your doctor may recommend a course of treatment to reduce the risk that you’ll develop active TB. This is often called TB prophylaxis.
TB that is causing illness is treated with a combination of antibiotics. Treatment usually lasts for six months, but can take longer. Researchers are looking for new combinations and doses of TB drugs to find ones that could make the course of treatment shorter.
Seek medical advice urgently if you develop:
- jaundice (yellowing of the skin or eyes)
- nausea or vomiting (feeling or being sick)
- a skin rash
- tingling in your hands or feet
- a fever or changes to your vision.
Most people are no longer infectious after two weeks of TB treatment and start to feel better after a few weeks or months.
It’s very important to take TB treatment as prescribed, even as it takes effect and you start to feel better. Otherwise TB can become resistant to the drugs that were used to treat it and this means the drugs will stop working. It can also mean the TB will come back.
Resistant TB is harder to treat and is much more serious. If TB is resistant to two or more of the main TB drugs, it’s called multidrug-resistant tuberculosis (MDR-TB). This can usually be treated successfully, but doctors will have to work out which drugs will work.
Some TB is resistant to many of the TB drugs available. This is called extensively drug-resistant TB (XDR-TB). Many of these cases seen in the UK have been in people with HIV.
Can TB and HIV be treated at the same time?
It can be difficult to treat TB and HIV at the same time. This is because some anti-HIV drugs can interact with anti-TB drugs.
In addition, taking HIV treatment when you have active TB can cause a condition called immune reconstitution inflammatory syndrome (IRIS). Find out more about HIV drug interactions.
If your CD4 cell count is below 100 you should start HIV treatment as soon as possible after starting anti-TB drugs.
If your CD4 cell count is over 100, it’s recommended that you start HIV treatment as soon as possible, but you can wait up to two months after starting TB treatment if you and your doctor think it would be useful. This could be to help you get used to one treatment before starting the other.