What is Meningitis?
Meningitis is not caused by just one organism; there is bacterial meningitis, viral meningitis, and meningitis caused by other organisms. This article is about bacterial meningitis, and particularly meningococcal meningitis, because it is currently the most common type of meningitis that causes serious disease and can produce outbreaks. Viral meningitis is more common overall, but it does not usually cause serious disease and most patients recover completely at home.The most common cause of bacterial meningitis is a bacteria called Neiseria meningitidis. This bug is also called meningococcus. There are other types of bacterial meningitis, too; the most notable ones are Haemophilus influenza type B (Hib) and Streptococcus pnuemoniae.
Is Bacterial Meningitis Serious?
Meningitis can cause hearing damage, brain damage, amputation of limbs and death, but it can begin with mild symptoms that may initially go by unnoticed. Infants are at high risk for getting meningitis, but vulnerability increases again for adolescents and young adults as well as people with underlying diseases that affect the immune system.Ten to 15% of meningitis cases are fatal within 24 to 48 hours, and of those who recover, 11 to 19% have permanent hearing loss, mental retardation, loss of limbs, or other serious complications.
How Can You Get Meningococcal Meningitis?
The bacteria are passed from person to person through droplets of respiratory or throat secretions, like those thrown out when sneezing or coughing. Close, long-term contact spreads the disease, as does kissing, sneezing and coughing, living together with many other people, and sharing eating or drinking utensils.The average time between catching the bacteria and getting the disease is 4 days, but can be as short as 2 days and as long as 10 days. Meningitis cases peak during the winter and spring in Europe and North America, but it's the dry season when Africa sees a spike in meningitis cases. People with weakened immune systems are susceptible to getting meningococcal meningitis, but healthy individuals also get struck down with the disease.
Symptoms of Meningitis
Meningitis symptoms vary depending on the age of the patient and the severity of the disease.Diagnosis of Meningococcal Meningitis
The diagnosis of meningococcal meningitis is based on symptoms and an examination of cerbrospinal fluid taken by a lumbar puncture, also called a spinal tap.The diagnosis is confirmed by growing the bacteria from samples of the spinal fluid. Only specialized laboratories can identify the serogroups of the bacteria or test for drug resistance.
There are 2 different kinds of rapid diagnostic tests for meningitis, but they need to be done by lab technicians after a lumbar puncture.
How is it Treated
Meningococcal disease can be fatal and is considered a medical emergency. The infected individual must be admitted to the hospital at once and isolation may be necessary. Treatment with antibiotics should be started immediately after a lumbar puncture has been done. The reason antibiotics are started after the puncture and not before is that antibiotics make growing the bacteria in the spinal fluid difficult, complicating diagnosis and treatment. If the lumbar puncture is delayed, however, treatment may be started anyway, because each minute that goes by without treatment is a matter of life and death. Steroids may also be given.There are several different antibiotics that your doctor may use to treat meningitis: penicillin, ampicillin, chloramphenicol, ceftriaxone and vancomycin.
During meningitis epidemics in Africa, oily chloramphenicol is the drug of choice in areas with limited health facilities because only a single dose of this long-acting formulation is needed.
According to the CDC, the risk of dying from meningitis is less than 15% if antibiotic treatment is begun immediately. For the elderly, the risk of death is higher.
How Is Meningitis Prevented?
- Meningitis vaccines can prevent many types of meningitis.
- Meningitis is caused by different bacteria that attack people of different ages and health conditions. Read about meningitis prevention for:
- If someone close to you has had meningitis, ask your doctor about receiving antibiotics to prevent getting meningitis.
Meningococcal Meningitis Information for Travelers
Bacterial and viral meningitis are found in every country in the world. The World Health Organization reports meningococcal meningitis outbreaks around the world. Meningococcal meningitis is divided into 4 types called serogroups A, B, C, and W135. Don't get bogged down by the letters and numbers; they are just there to distinguish the different types of the same bacteria, Neiseria meningitidis, sometimes shortened to N. meningitidis.N. Meningitidis serogroups B and C together account for most cases in Europe and the Americas. Several local outbreaks due to N. meningitidis serogroup C have been reported in Canada and the United States (1992-93) and in Spain (1995-97). In the last 10 years, New Zealand has seen an increase in meningitis; an average of 500 cases a year, mostly due to serogroup B.
In Africa, serogroups A and C are usually the cause of meningitis, whereas serogroup A is the main culprit of meningitis in Asia. Most large outbreaks have occurred in Africa, but Mongolia also had a large epidemic in 1994-5.
A bacteria on the rise in the meningitis world is N. meningitidis serogroup W135 which has been the cause of large meningitis outbreaks. Hundreds of Muslims attending the sacred Hajj pilgrimage in 2000 and 2001 were struck with this type of meningitis. In 2002, the same serogroup caused meningitis in Burkina Faso infecting 13,000 people and killing 1,500. The CDC's website for Traveler's Health has more information on the meningitis vaccination requirement for travelers to Mecca and Medina.