Meningitis types, causes and treatments
What is meningitis?
Meningitis is a serious but relatively rare medical condition. The symptoms of meningitis can come on quickly and need urgent medical attention.
Meningitis affects membranes covering the brain and spinal cord called the meninges.
Meningitis can be causes by bacteria or a virus. Fungal meningitis is a rare form and usually only affects people with weakened immune systems.
Around 3,400 people get bacterial meningitis and associated septicaemia each year in the UK.
Around 50% of meningitis cases in the UK are among under 5s, babies and toddlers.
University students are also at a higher risk of meningitis with 15-19 years two and a half times more like to carry olds carry a meningitis causing bacteria than adults.
What causes meningitis?
Meningitis is almost always caused by a bacterial or viral infection that began elsewhere in the body, such as in the ears, sinuses or upper respiratory tract. Less common causes of meningitis include fungal infection, immune system disorders and medications.
The bacterial form of meningitis is an extremely serious illness that requires immediate medical attention. If not treated quickly, it can lead to death within hours or to permanent brain damage.
Bacterial meningitis is caused by any one of several bacteria. Neisseria meningitidis, or “meningococcus”, is common in young adults, and Streptococcus pneumoniae or “pneumococcus” is the most common form in adults. Haemophilus influenza type b (Hib) was a common form in infants until the Hib vaccine was introduced for infants. Meningococcus and pneumococcus account for most of the bacterial meningitis cases in the UK.
Meningitis C vaccination is part of the NHS childhood vaccination programme with a booster jab now given to 12-13 year olds.
There is also a vaccine available for meningitis B, which is not yet part of routine childhood vaccination.
The bacteria can spread from person to person through coughing and sneezing. If you are around someone who has bacterial meningitis, seek medical advice to ask if you need to take steps so you don’t become infected. In many instances, bacterial meningitis develops when bacteria get into the bloodstream from the sinuses, ears or other part of the upper respiratory tract. The bacteria then travel through the bloodstream to the brain.
Viral meningitis is more common than the bacterial form and generally, but not always, less serious. It can be triggered by a number of viruses, including several that can cause diarrhoea. People with viral meningitis are much less likely to have permanent brain damage after the infection resolves. Most will recover completely.
Fungal meningitis is much less common than the other two infectious forms. Fungus-related meningitis is rare in healthy people. However, somebody who has an impaired immune system, such as a person with AIDS, is more likely to become infected with this form of meningitis.