TB meningitis is caused by the bacterium Mycobacterium tuberculosis. Infection usually begins elsewhere in the body, often the lungs, but in about 2% of cases the bacteria travel via the bloodstream to the meninges and cause TB meningitis.
Unlike other types of meningitis that develop quickly, e.g. meningococcal or pneumococcal, TB meningitis usually develops slowly with vague symptoms such as tiredness and headaches. These can last for several weeks before the more specific symptoms of meningitis occur. This slow progression makes the disease difficult to diagnose and it is often advanced before treatment begins.
There is a vaccine to protect against TB meningitis. It is given to those who are at greatest risk.
Although many people will make a good recovery, some will be left with life-changing after-effects and some will die.
The facts
- TB meningitis usually develops slowly
- Anyone can get TB and therefore TB meningitis, but it is more likely to affect those living in poor conditions, such as the homeless and those with other illnesses - especially HIV infection
- TB infection usually begins in the lungs and in about 1 - 2% of cases the infection can progress to TB meningitis
- At least 20% will suffer long-term after-effects. These are often severe and may include severe brain damage, epilepsy, paralysis and hearing loss
- Tragically, between 15-30% of patients will die, despite receiving treatment and care
Download our TB meningitis fact sheet.
Symptoms of TB meningitis
- TB meningitis can initially display vague symptoms such as aches and pains, loss of appetite and tiredness, usually with a persistent headache
- These vague symptoms can last for several weeks before more specific symptoms of meningitis, such as severe headache, dislike of bright lights and neck stiffness occur
- The slow progression of the disease makes it difficult to diagnose and it is often advanced before treatment begins
How is TB meningitis caused?
Tuberculosis bacteria enter the body by droplet inhalation i.e. breathing in bacteria from the coughing/sneezing of an infected person.
- The bacteria multiply within the lungs, pass into the bloodstream and are able to travel to other areas of the body
- If the bacteria travel to the meninges (protective layers that protect the brain) and brain tissue, small abscesses (tubercles/microtubercles) are formed
- These abscesses can burst and cause TB meningitis. This can happen immediately, or several months or years after the initial infection
- The infectious process causes a rise in pressure within the skull, resulting in nerve and brain tissue damage, which is often severe
Areas of the world with a high incidence of TB
- Africa
- South East Asia
- Eastern Mediterranean
- Western Pacific
- Russia
- China
- South America
People working or travelling in these areas should seek advice about BCG vaccination. In areas of the world where the incidence of TB is high, TB meningitis is most common in children under five. Where the incidence of TB is low, most TB meningitis cases are in adults.
How is TB meningitis treated?
Due to the slow progression and non-specific early symptoms of TB meningitis, diagnosis can be difficult. However, research has shown that early diagnosis and treatment can significantly improve the outcome of the disease.
- If treatment is started early, most people will make a good recovery provided that the treatment course is completed
- TB meningitis requires admission to hospital and close monitoring to assess the progression of the disease
- Each patient will be individually assessed and their care planned accordingly. All patients will be given a combination of antibiotics to treat the infection
- In the UK, isoniazid, rifampicin, pyrazinamide and a fourth drug (e.g. ethambutol) are usually given for the first two months, followed by isoniazid and rifampicin for the next ten months. This combination is given to reduce the risk of antibiotic resistance developing
- Treatment may vary according to the response of the individual patient
- Drug resistant TB meningitis may require long schedules of treatment with a variety of alternative antibiotics. A steroid (e.g. prednisolone) is also often recommended for the first few weeks of treatment
- It is essential that the full course of treatment is completed. This will reduce the risk of the disease returning and of the bacteria becoming resistant to the antibiotics
What happens when there is a case of TB meningitis?
In order to develop TB meningitis, a person will have acquired the bacteria via the lungs and may therefore have active TB in areas of the body other than the brain.
- Contacts of the person with TB meningitis will be offered testing and, where appropriate, antibiotic treatment and/or BCG vaccination
- It is possible for a person to be infected with the TB bacteria, but not develop TB disease. This is known as latent TB because the TB bacteria are not active in the body. The person is usually well and cannot pass the bacteria to other people
- However, there is a risk that latent TB may develop into active TB and, for this reason, latent TB is still treated with antibiotics, but for a shorter length of time
Can TB meningitis be prevented?
Yes, there is a vaccine known as BCG. This vaccine is effective in babies and young children. It gives good protection against the more severe forms of TB, such as TB meningitis.
- BCG vaccine used to be offered to all children at secondary school in the UK. Due to changes in the distribution and occurrence of TB in the UK, the vaccine is now offered to those individuals who are at greatest risk
- The current programme of vaccination targets babies, children and young people who are most likely to catch the disease
- The vaccine is also recommended for healthcare workers who may be exposed to TB
For more information about the BCG vaccine visit the NHS website.
