There are two types of meningitis: bacterial and viral. When diagnosing meningitis, it important to find out which of the two forms it is. This is because there are differences in the seriousness of the illness, as well as the treatment needed. Bacterial meningitis is very serious. Severe bacterial meningitis can result in brain damage and even death. Viral (aseptic) meningitis is usually mild and clears up within a week or two without specific treatment.

Bacterial meningitis is much more serious than viral meningitis. It can cause severe brain damage and even death. Bacterial meningitis is a serious infection of cerebrospinal fluid surrounding the brain and spinal cord. It is most commonly caused by one of three types of bacteria: haemophilus influenzae type B, neisseria meningitidis, and streptococcus pneumoniae. The bacteria are spread by direct contact with the discharges from the nose or throat of an infected person. This form of meningitis can be treated with antibiotics. Its prevention depends on use of vaccines, rapid diagnosis, and prompt treatment of infected people.

Viral meningitis is caused by many different viruses. In fact, about half of the cases in the United States are caused by common intestinal viruses. Mosquito-borne viruses also cause some cases. In many cases, a specific virus cannot be identified. Cases occurring in summer and fall are usually caused by mosquito-borne viruses. The disease is usually spread by person-to-person contact; other cases are spread by insects. Symptoms include fever, headache, stiff neck, tiredness, rash, sore throat, and vomiting, and generally appear within 1 week of exposure. The Illness usually lasts no more than 10 days, and the recovery is usually complete. Viral meningitis is diagnosed by blood tests. No treatment is available for viral meningitis since antibiotics do not work against viruses. Infection can be prevented by washing the hands and avoiding mosquitoes as much as possible.