Bacterial meningitis is a contagious and potentially lethal infection. Recent cases at Princeton and Drexel universities and the infection of an 8-year-old Collegeville elementary school student have raised concerns about the disease across the area. I hope to provide anxious parents with some understanding of the nature of this disease and its spread.
Historically, three species of bacteria accounted for the vast majority of cases of childhood bacterial meningitis: Hemophilus influenzae type b, Streptococcus pneumoniae, and Neisseria meningitides. The advent of modern vaccines has eliminated the disease caused by the first two bacteria for the most part. Neisseria meningitides remains as the most common cause of disease among healthy children and adolescents in the United States.
The disease is spread by respiratory secretions. While the disease is contagious, the attack rate is relatively low. Among household contacts of individuals with meningococcal disease, secondary cases appear at a rate of 2 to 4 in 1,000 household contacts. Children under 5, adolescents and young adults, and the elderly are the groups at highest risk for infection. Most cases occur as single instances, but outbreaks of the disease do occur, often on college campuses or in military barracks.
Infected individuals or individuals who harbor the organism without symptoms spread the disease through coughing and sneezing. The organism gains access to the respiratory tract of a susceptible individual, spreads to the bloodstream, and ultimately lodges in the meninges, the lining of the brain. Here, the organism causes inflammation and swelling which ultimately damages the underlying brain.
The onset of symptoms is rapid: fever, headache and malaise are followed by neck stiffness, decreased awareness of the surroundings and coma. This progression of symptoms usually occurs over hours. The diagnosis is made by examining the spinal fluid and treatment includes the administration of antibiotics. Neisseria meningitides is not a particularly hearty nor drug-resistant bacterium and is easily killed by conventional drugs. Unfortunately, the tempo of the disease is such that irrevocable damage may be done before the patient reaches medical attention.
There are five strains of Neisseria meningitides that cause disease in humans. Infection by 4 of these strains can be prevented by routine immunization. Protection against infection by the fifth strain, type B, is not currently available although an investigational vaccine against this strain was made available to students at Princeton.
So what should parents do to protect their children against meningitis?
- Make sure your child is fully vaccinated. HIB vaccine and pneumococcal conjugate vaccines are recommended for infants beginning at 2 months of age and will prevent meningitis due to these organisms in young children.
- Meningococcal vaccine (active against 4 strains) is recommended for all children aged 11 to 18 years with the first dose administered between 11 and 12 years and the second dose at 16 years of age. Selected individuals may require additional booster doses every 5 years. Children with certain medical conditions may be vaccinated as early as 2 months of age and children travelling to high risk areas may be vaccinated at 9 years of age.
- The prophylactic or preventative use of antibiotics is recommended for certain individuals who have had close contact with someone with meningococcal meningitis. These individuals include:
- Household contacts, particularly children less than 2 years of age;
- Individuals who attend childcare or daycare and had contact within 7 days of the onset of illness;
- Any individual who had direct contact with the patient’s respiratory secretions (e.g. kissing, mouth to mouth resuscitation, sharing a toothbrush) during the 7 days prior to the onset of illness;
- Individuals who frequently slept in the same dwelling as the patient during the 7 days prior to the onset of illness;
- Passengers seated next to the patient during any flight of 8 hours or longer.
- Secondary cases of meningococcal meningitis usually appear within 1 week of the first case. If your child had contact with such an individual and develops a fever, regardless of antibiotic prophylaxis, seek medical attention immediately.