Meningitis

Meningitis is an inflammation of the linings of the brain and spinal cord caused by either viruses or bacteria.

Viral meningitis is more common than bacterial meningitis and usually occurs in late spring and summer. Signs and symptoms of viral meningitis may include stiff neck, headache, nausea, vomiting and rash. Most cases of viral meningitis run a short, uneventful course. Since the causative agent is a virus, antibiotics are not effective. Persons who have had contact with an individual with viral meningitis do not require treatment.

Bacterial meningitis occurs rarely and sporadically throughout the year, although outbreaks tend to occur in late winter and early spring. Bacterial meningitis in college-aged students is most likely caused by Neisseria meningitidis (meningococcal meningitis) or Streptococcus pneumoniae. Because meningococcal meningitis can cause grave illness and rapidly progress to death, it requires early diagnosis and treatment. In contrast to viral meningitis, persons who have had intimate contact with a case require prophylactic therapy. Untreated meningococcal disease can be fatal.

Approximately 10 percent of the general population carry meningococcal bacteria in the nose and throat in a harmless state. This carrier state may last for days or months before spontaneously disappearing, and it seems to give persons who harbor the bacteria in their upper respiratory tracts some protection from developing meningococcal disease.

During meningococcal disease outbreaks, the percentage of people carrying the bacterium may approach 95 percent, yet the percentage of people who develop meningococcal disease is less than 1 percent. This low occurrence of disease following exposure suggests that a person’s own immune system, in addition to bacterial factors, plays a key role in disease development.

Meningococcal bacteria cannot usually live for more than a few minutes outside the body. As a result, they are not easily transmitted in water supplies, swimming pools or by routine contact with an infected person in a classroom, dining room, bar, restroom, etc.

Roommates, friends, spouses and children who have had intimate contact with the oral secretions of a person diagnosed with meningococcal disease are at risk for contracting the disease and should receive prophylactic medication immediately. Examples of such contact include kissing, sharing eating utensils or beverages and being exposed to droplet contamination from the nose or throat.

The incidence of meningococcal disease has declined steadily in the U.S. since a peak of reported disease in the late 1990s. Even before routine use of a meningococcal conjugate vaccine (MenACWY) in adolescents was recommended in 2005, the overall annual incidence of meningococcal disease had decreased 64 percent, from 1.1 cases per 100,000 population in 1996 to 0.4 cases per 100,000 population in 2005. In 2018, the rate of meningococcal disease in the U.S. reached a historic low of 0.1 cases per 100,000 population. Incidence of disease caused by serogroup B, a serogroup not included in the routinely recommended MenACWY vaccine, also has declined for reasons that are not known.

From 2015 to 2018, an estimated 360 cases of meningococcal disease occurred annually in the United States, representing an average annual incidence of 0.11 cases per 100,000 population. Of those with known serogroup in 2018 (N=302), 39 percent were serogroup B and 51 percent were serogroups C, Y or W- 135. The incidence of disease is highest in infants 1 year old and under, and adolescents age 16 to 20 years old.

Meningococcal disease is potentially dangerous because it is relatively rare and can be mistaken for other conditions. The possibility of having meningitis may not be considered by someone who feels ill, and early signs and symptoms may be ignored. A person may have symptoms suggestive of a minor cold or flu for a few days before experiencing a rapid progression to severe meningococcal disease.

Understanding the characteristic signs and symptoms of meningococcal disease is critical and possibly lifesaving. Common early symptoms of meningococcal meningitis include fever, severe sudden headache accompanied by mental changes (e.g. malaise, lethargy) and neck stiffness. A rash may begin as a flat, red eruption, mainly on the arms and legs. It may then evolve into a rash of small dots that do not change with pressure (petechiae). New petechiae can form rapidly, even while the patient is being examined.

Meningococcal disease can be rapidly progressive. However, with early diagnosis and treatment, the likelihood of a full recovery is increased. Early recognition, performance of a lumbar puncture (spinal tap) and prompt initiation of antimicrobial therapy are crucial. For chemoprophylaxis, the use of such prophylactic antibiotics as ciprofloxacin or rifampin is recommended for those who may have been exposed to a person diagnosed with meningococcal disease. Anyone who suspects possible exposure should consult a practitioner immediately.

The Advisory Committee on Immunization Practices (ACIP) to the Centers for Disease Control and Prevention (CDC) recommends routine vaccination for first-year college students living in residence halls. The University of Delaware requires meningitis ACWY vaccination for all incoming students living in campus residence halls and recommends meningitis B vaccine.

The vaccines for meningococcal serogroups A, C, W and Y (MenACWY; Menactra, Sanofi Pasteur; Menveo, GlaxoSmithKline [GSK]; MenQuadfi, Sanofi Pasteur) contain meningococcal conjugate in which the surface polysaccharide is chemically bonded (“conjugated”) to a protein to produce a robust immune response to the polysaccharide. Although each of the three MenACWY vaccine products uses a different protein conjugate, the products are considered interchangeable; the same vaccine product is recommended, but not required, for all doses.

Since late 2014, vaccines have become available that offer protection from meningococcal serogroup B disease (MenB; Bexsero, GSK; Trumenba, Pfizer). These vaccines are composed of proteins found on the surface of the bacteria. These vaccine products are not interchangeable; the same vaccine product is required for all doses.

MenACWY vaccines provide no protection against serogroup B disease, and meningococcal serogroup B vaccines (MenB) provide no protection against serogroup A, C, W or Y disease. For protection against all five serogroups of meningococcus, it is necessary to receive both MenACWY and MenB.