Meningococcal Meningitis

(This information is not intended to be a substitute for the advice of a doctor or a recommendation for any particular treatment plan. Like any printed material, it may become out of date over time. It is important that you rely on the advice of a doctor for your specific condition.)

The infectious agent is a gram-negative diplococci, Neisseria meningitidis. The 5 major meningococcal sero-groups associated with disease are A, B, C, Y, and W-135. Person-to-person transmission occurs by close contact with respiratory secretions or saliva.

N. meningitidis is found worldwide. At any time, 5%–10% of the population may be carriers of N. meningitidis. The incidence of meningococcal disease is highest in the “meningitis belt” of sub-Saharan Africa, with periodic epidemics during the dry season (December–June). During non-epidemic periods, the rate of meningococcal disease is roughly 5–10 cases per 100,000 population per year. During epidemics, the rate can be as high as 1,000 cases per 100,000 populations. Young children have the highest risk for meningococcal disease, but 60% of cases occur in adolescents and adults. Risk is highest in travelers who have prolonged contact with local populations in the meningitis belt during an epidemic. The Hajj pilgrimage to Saudi Arabia has been associated with outbreaks of meningococcal disease in returning pilgrims and their contacts.

Meningococcal disease generally occurs 1–14 days after exposure. Meningococcal disease presents as meningitis in ≥50% of cases. Meningococcal meningitis is characterized by sudden onset of headache, fever, and stiffness of the neck, sometimes accompanied by nausea, vomiting, photophobia, or altered mental status. Up to 20% of people with meningococcal disease present with meningococcal sepsis, known as meningococcemia. Meningococcemia is characterized by an abrupt onset of fever and a petechial or purpuric rash. The rash may progress to purpura fulminans. Meningococcemia may often involve hypotension, acute adrenal hemorrhage, and multi-organ failure.

Early diagnosis and treatment are critical. If possible, a lumbar puncture should be done before starting antibiotic therapy to ensure that bacteria, if any, can be cultured from cerebrospinal fluid (CSF). Diagnosis is generally made by isolating N. meningitidis from blood or CSF, by detecting meningococcal antigen in CSF by latex agglutination, or by evidence of N. meningitidis DNA by PCR.

The signs and symptoms of meningococcal meningitis are similar to those of other causes of bacterial meningitis, such as Haemophilus influenzae and Streptococcus pneumoniae. The causative organism should be identified so that the correct antibiotics can be used for treatment and prophylaxis.

Meningococcal disease is potentially fatal and should always be viewed as a medical emergency. Antibiotic treatment must be started early in the course of the disease. Several antibiotic choices are available, including ceftriaxone, cefotaxime, chloramphenicol, and benzylpenicillin. Add rifampicin 600 mg every 12 hours for 2 days to patients in order to eliminate nasopharyngeal carriage.

In case the causative organism of meningitis or community-acquired pneumonia can not be differentiated among Neisseria meningitidis - Haemophilus influenzae - Streptococcus pneumoniae, cephalosporins of the third generation (such as cefotaxime and ceftriaxone) may be used in combination with fluoroquinolones (such as levofloxacin and moxifloxacin).

Vaccination against meningococcal disease is recommended to people who travel to or reside in countries where N. meningitidis is hyper-endemic or epidemic, particularly if contact with the local population will be prolonged. Hyper-endemic regions include the meningitis belt of Africa during the dry season (December–June). Note that proof of receipt of quadrivalent vaccination against meningococcal disease is required for people traveling to Mecca during the annual Hajj and Umrah pilgrimages.

There are two kinds of meningococcal vaccine: meningococcal conjugate vaccine and meningococcal polysaccharide vaccine. Both vaccines can protect against meningococcal disease caused by sero-groups A, C, Y, and W-135. Approximately 7–10 days are required after vaccination for development of protective antibody levels.

Travelers who were vaccinated previously and are living in or returning to the meningitis belt may need to be revaccinated, if it has been >5 years since their last meningococcal vaccine. Travelers to the Hajj must show proof of vaccination in the previous 3 years. Previously unvaccinated travelers who have a history of complement component deficiency (C3, properdin, factor D, or late component), functional or anatomic asplenia, or HIV should receive a two-dose primary series of meningococcal conjugate vaccine, 2 months apart, prior to travel if possible.

(Source: U.S. Centers for Disease Control and Prevention & National Foundation for Infectious Diseases)