Cause
An inflammation of the meninges, the membrane covering the brain and spinal cord, meningitis can be caused by bacteria, viruses, fungi, or parasites that enter into the cerebrospinal fluid from the blood. Streptococcus pneumoniae, Neisseria meningitidis, and Hemophilus influenzae type B are the most common bacteria causing the infection in children. Enteroviruses are the most frequent viral cause. Bacterial infections are generally more serious than viral defects of the meninges and are potentially life-threatening.
Symptoms
Symptoms may include fever, severe headache, stiff neck, nausea, vomiting, irritability, sensitivity to light, seizure, rash, bulging fontanel (soft spot on top of the head) in infant, rash or bruise marks, confusion, or coma (unconsciousness).
How It Spreads
The bacteria and viruses are usually spread by contact with infected feces or nose and throat drops. Typically, the infection begins in the respiratory system, but it can begin in other parts of the body, including the heart valves, bones, ears, nose, or teeth.
Incubation Period
This varies with the organism. For enteroviruses, the incubation period is 3 to 6 days; other viruses may range from 4 to 21 days. Once the infection has entered the spinal fluid, symptoms usually occur rapidly.
How Long Symptoms Last
The duration of symptoms varies according to cause. Once treatment begins, fever associated with bacterial infection usually resolves in 5 to 7 days, but fever longer than 10 days occurs in 10 percent of children. Viral infections usually are milder and symptoms last several days.
When to Call Your Child’s Doctor
Call your child’s doctor immediately if your child has any of these symptoms: persistent vomiting, severe headache, stiff neck, lethargy or confusion, rash, or fever. In infants, also look for a bulging soft spot, irritability, poor feeding, and lethargy. If your child has had contact with someone with meningitis, consult your child’s doctor.
How the Diagnosis Is Made
A lumbar puncture, or spinal tap, is performed to examine the spinal fluid. Blood and urine tests may also be done.
Treatment
Often antibiotics and intravenous fluids are given before the organism is identified, and the child is placed in isolation in the hospital. If the cause is a virus, the antibiotics will be stopped and the child may be given a pain reliever such as acetaminophen and, in some cases, intravenous fluids. If the cause is bacterial, antibiotics will be continued for up to several weeks; corticosteroids to relieve inflammation may also be given.
Prevention
The Hemophilus influenzae type B vaccine, given to infants beginning at two months, is 70 to 100 percent effective in protecting against this cause of meningitis. Children younger than two years and children with weakened immune systems should be vaccinated against Streptococcus pneumoniae. For children exposed to meningitis caused by certain bacteria, the doctor may prescribe the antibiotic rifampin to prevent infection.
Complications
Most children completely recover from viral meningitis. Severe cases can result in seizures and intellectual, motor, hearing, visual, and psychiatric problems. In bacterial infections, the mortality rate in infants (after the newborn period) and children is 1 to 8 percent. Significant neurological and developmental problems occur in 10 to 20 percent of patients surviving the infection, including hearing loss, mental retardation, seizures, delay in speaking, visual impairment, and behavioral problems.