October 21, 2011
Dear Mayo Clinic:
The stories about meningitis I hear in the news sound pretty scary. What causes meningitis? How can I protect myself and my kids against it?
Meningitis is inflammation of the membranes around the brain and spinal cord. Usually, it results from an infection. Rarely, meningitis may be caused by medications or autoimmune conditions such as systemic lupus erythematosus. The steps you take to prevent other infections — such as washing your hands before eating and covering your mouth when coughing — can help prevent meningitis. But the best protection against meningitis is to stay up-to-date with immunizations.
Many cases of meningitis are caused by viral infections. A number of different viruses can cause meningitis, but most are from a group known as enteroviruses. Viral meningitis is usually mild and goes away on its own without treatment. Generally, viral meningitis is less severe than bacterial meningitis. Rest, extra fluids and over-the-counter pain medication are all most people need while recovering.
Meningitis is sometimes caused by infectious agents transmitted by mosquitoes and ticks, so wearing protective clothing and insect repellent in the spring and summer can also help reduce your chances of developing meningitis.
In contrast to viral meningitis, bacterial meningitis is a medical emergency. If left untreated, it can be life-threatening. The most common causes of bacterial meningitis are three main bacteria: Streptococcus pneumoniae, Haemophilus influenzae and Neisseriameningitidis.
Streptococcus pneumoniae often causes bacterial meningitis in infants, young children and adults. This bacterium can also cause pneumonia, ear infections and sinus infections. Haemophilus influenzae was once the leading cause of bacterial meningitis in children. But today, the routine childhood immunization schedule in the United States includes a vaccine against this bacterium, greatly reducing the number of cases of this type of meningitis.
Meningitis caused by Neisseria meningitidis often occurs when bacteria from an upper respiratory infection enter the bloodstream. This infection is highly contagious and frequently affects teenagers and young adults. Neisseria meningitidis sometimes causes outbreaks of meningitis at college dormitories, boarding schools, military bases and other places where people live in close quarters. Likely, the cases of meningitis you've heard about in the news are due to this form of bacterial meningitis.
Bacterial meningitis often requires hospitalization and treatment with antibiotics for one to two weeks. Although this infection is very serious, many patients can make a full recovery if it's treated right away.
Common symptoms of meningitis in adults, teens and children older than 2 can include severe headache, a stiff neck, fever above 101 degrees Fahrenheit, confusion or difficulty concentrating, sensitivity to bright light, vomiting, and sleepiness or difficulty waking up. For newborns and infants, symptoms may include high fever, constant crying, excessive sleepiness or irritability, inactivity or sluggishness, poor feeding, a bulge in the soft spot (fontanelle) on top of the baby's head, stiffness in the baby's body and neck, or seizures. Bacterial meningitis symptoms are usually more severe than those from viral meningitis.
In general, cases of bacterial meningitis have decreased significantly over the past several decades because vaccines that protect against several of the bacterial forms of meningitis have been added to the immunizations children and teens typically receive. Making sure your children get their immunizations on time is the most important step you can take to lower their chances of developing bacterial meningitis.
If you suspect meningitis — particularly if flulike symptoms seem more severe than usual or are accompanied by neck stiffness or confusion — seek medical care right away. The earlier treatment for bacterial meningitis starts, the better the outcome is likely to be.
— Ritu Banerjee, M.D., Ph.D., Pediatric Infectious Diseases, Mayo Clinic, Rochester, Minn.