Bacterial meningitis is a medical emergency.
Untreated, it can be fatal in a few hours. Even survivors can have severe consequences including varying degrees of blindness, deafness, paralysis and mental retardation. Suspected cases of bacterial meningitis require immediate medical attention.
At least 50 different bacteria cause meningitis. Of the more than 1000 cases there are in Canada every year, most are caused by one of four bacteria: meningococcus (link to 4), Pneumococcus (link to 4), Group B Streptococcus (link to 4), or E. coli (link to 4).
Most cases (75%) of meningococcus infection are meningitis. Most of the rest (20%) are septicemia (severe blood poisoning). Other possible meningococcus infections include pneumonia and arthritis. It is important to note that septicemia is much more likely to be fatal than meningitis. Although the two diseases begin with similar symptoms there are marked differences and anyone with symptoms of septicemia must be give immediate medical attention. (Septicemia Symptoms link to 4) Vaccines are available to protect against meningococcus. (Vaccines link)
Pneumococcus causes many different infections including pneumonia, bronchitis, ear and sinus infections, blood infection and, less frequently, meningitis. Pneumococcal meningitis is rare in Canada. Children under 2 and people with compromised immune systems are most susceptible and there are vaccines available. (Vaccines link)
Group B Streptococcal (GBS) bacteria live in the throat, intestines and vagina of at least 30 per cent of the population, without causing any ill effects. Most GBS infections occur in babies less than 3 months at the rate of approximately 1 in 1000 births. Even if the mother does carry GBS, her baby will not likely become ill because of the antibodies the mother transfers to the baby during the last few weeks of pregnancy. Premature infants, born before the transfer of antibodies, are at a much greater risk. GBS infection results in pneumonia, septicemia, meningitis, or a combination of diseases.
E. coli bacteria live in the colon of all healthy people and most mammals. There are more than 150 different types. E. coli meningitis usually occurs in newborn babies and in the elderly. Premature and low birth-weight babies are at much higher risk than full term newborns.
Less common bacteria that do cause some meningitis in Canada are H flu b or Hib, Listeria, and tuberculosis or TB. Before 1992, Hib was the most common cause of bacterial meningitis, usually in children less than 5 years old. It is rare in Canada now because all infants are immunized with a very effective Hib vaccine.
Listeria meningitis occurs mainly in newborn babies, the elderly, and people whose immune systems are compromised. Only a few cases occur each year but almost one-third are fatal.
TB meningitis is uncommon in Canada. It can occur at any age but it is most frequent in infants. Diagnosis can be difficult because it usually takes a longer time to develop than other bacterial meningitis.
Symptoms, Prognosis, and Treatments of bacterial meningitis vary with the underlying cause of the disease. For more details, see the expanded information on the individual types.