Meningitis is an inflammation of the meninges, the membranes that cover the brain and spinal cord. Most cases are caused by bacteria or viruses, but some can be due to certain medications or illnesses.
Bacterial meningitis is rare, but is usually serious and can be life threatening if not treated right away. Viral meningitis (also called aseptic meningitis) is relatively common and far less serious. It often remains undiagnosed because its symptoms can be similar to those of the common flu.
People of any age can get meningitis, but because it can be easily spread among those living in close quarters, teens, college students, and boarding-school students are at higher risk for infection.
If dealt with promptly, meningitis can be treated successfully. So it's important to get routine vaccinations, know the signs of meningitis, and if you suspect that your child has the illness, seek medical care right away.
Causes of Meningitis
Many of the bacteria and viruses that cause meningitis are fairly common and associated with other routine illnesses. Bacteria and viruses that infect the skin, urinary system, or gastrointestinal and respiratory tract can spread by the bloodstream to the meninges through cerebrospinal fluid, the fluid that circulates in and around the spinal cord.
In some cases of bacterial meningitis, the bacteria spread to the meninges from a severe head trauma or a severe local infection, such as a serious ear infection (otitis media) or nasal sinus infection (sinusitis).
Bacterial and Viral Types
Many different types of bacteria can cause bacterial meningitis. In newborns, the most common causes are Group B streptococcus, Escherichia coli, and less commonly, Listeria monocytogenes. In older kids, Streptococcus pneumoniae (pneumococcus) and Neisseria meningitidis (meningococcus) are more often the causes.
Another bacteria, Haemophilus influenza type b (Hib), also can cause the illness but because of widespread childhood immunization, these cases are rarer.
Similarly, many different viruses can lead to viral meningitis, including enteroviruses (such as coxsackievirus and poliovirus) and the herpesvirus.
Meningitis symptoms vary, depending both on the age of the patient and the cause of the infection. The first symptoms of bacterial or viral meningitis can come on quickly or surface several days after someone has had a cold, diarrhea and vomiting, or other signs of an infection.
Common symptoms include:
lethargy (decreased consciousness)
photophobia (eye sensitivity to light)
Meningitis in Infants
Infants with meningitis may not have common symptoms. They might simply have extreme irritability, lethargy, or fever. They may be difficult to comfort, even when they are picked up and rocked.
Other symptoms of meningitis in infants can include:
jaundice (a yellowish tint to the skin)
stiffness of the body and neck
fever or lower-than-normal temperature
a weak suck
a high-pitched cry
bulging fontanelles (the soft spot at the top/front of the baby's skull)
Viral meningitis tends to cause flu-like symptoms, such as fever and headache, and may be so mild that the illness goes undiagnosed. Most cases of viral meningitis resolve completely within 7 to 10 days, without any complications or need for treatment.
Because bacterial meningitis can be so serious, if you think that your child has any form of meningitis, it's important to see the doctor right away.
If meningitis is suspected, the doctor will order laboratory tests to help make the diagnosis, probably including a lumbar puncture (spinal tap) to collect a sample of spinal fluid. This test will show any signs of inflammation and whether a virus or bacteria is causing the infection.
Someone with viral meningitis may be hospitalized, although some kids are allowed to recover at home if they are not too ill. Treatment aimed at relieving symptoms includes rest, fluids, and over-the-counter pain medication.
If bacterial meningitis is diagnosed — or even suspected — doctors will start intravenous (IV) antibiotics as soon as possible. Fluids may be given to replace those lost to fever, sweating, vomiting, and poor appetite.
Complications of bacterial meningitis might require additional treatment. For example, anticonvulsants might be given for seizures. If someone develops shock or low blood pressure, additional IV fluids and certain medications might be given to increase blood pressure. Some kids may need supplemental oxygen or mechanical ventilation if they have difficulty breathing.
Bacterial meningitis complications can be severe and include neurological problems such as hearing loss, visual impairment, seizures, and learning disabilities. Because impaired hearing is a common complication, those who've had bacterial meningitis should have a hearing test following their recovery.
The heart, kidneys, and adrenal glands also might be affected, depending on the cause of the infection. Although some kids develop long-lasting neurological problems, most who receive prompt diagnosis and treatment recover fully.
How Meningitis Spreads
Most cases of meningitis — both viral and bacterial — are due to infections that are contagious, spread via tiny drops of fluid from the throat and nose of someone who is infected. The drops may become airborne when the person coughs, laughs, talks, or sneezes. They then can infect others when people breathe them in or touch the drops and then touch their own noses or mouths.
Sharing food, drinking glasses, eating utensils, tissues, or towels all can transmit infection as well. Some infectious organisms can spread through a person's stool (poop), and someone who comes in contact with the stool — such as kids in daycare — may develop the infection.
Infections most often spread between people who are in close contact, such as those who live together or people who are exposed by kissing or sharing eating utensils. Casual contact at school or work with someone who has one of these infections usually will not transmit the infectious agent.
Routine immunization can go a long way toward preventing meningitis. The vaccines against Hib, measles, mumps, polio, meningococcus, and pneumococcus can protect against meningitis caused by these microorganisms.
Doctors now recommend that kids get vaccinated for meningococcal disease when they're 11 years old, with a booster shot at age 16. The vaccine is called quadrivalent meningococcal vaccine, or MCV4. Kids who have not been vaccinated and are older than 11 also should be immunized, particularly if they're going to college, boarding school, camp, or other settings where they'll live in close quarters with others.
The vaccine also might be recommended for kids between 6 weeks and 10 years old who have certain high-risk medical problems, and for people traveling to countries where meningitis is more common.
Many of the bacteria and viruses responsible for meningitis are fairly common, so good hygiene is an important way to prevent infection. Encourage kids to wash their hands thoroughly and often, particularly before eating and after using the bathroom. Avoiding close contact with someone who is obviously ill and not sharing food, drinks, or eating utensils can help halt the spread of germs as well.
In certain cases, doctors may give antibiotics to anyone who has been in close contact with a person who has bacterial meningitis to help prevent additional infections.
When to Call the Doctor
Seek medical attention immediately if you suspect your child has meningitis or has symptoms such as vomiting, headache, lethargy or confusion, neck stiffness, rash, and fever. Infants who have fever, irritability, poor feeding, and lethargy should also be assessed by a doctor right away.
If your child has had contact with someone who has meningitis (for example, in a childcare center or a college dorm), call your doctor to ask whether preventive medication is recommended.