Amanda Cohn, Michael L. Jackson

Infectious Agent

• The infectious agent is a gram-negative diplococci, Neisseria meningitidis. Meningococci are classified into serogroups on the basis of the composition of the capsular polysaccharide.
• The five major meningococcal serogroups associated with disease are A, B, C, Y, and W-135.

Mode of Transmission

Person-to-person transmission occurs by close contact with respiratory secretions or saliva.

Occurrence

• Neisseria meningitidis is found worldwide. At any time, 5%–10% of the population may be carriers of N. meningitidis.
• Invasive disease is much rarer, occurring at a rate of 0.5–10 cases per 100,000 population in nonepidemic areas and up to 1,000 cases per 100,000 population in epidemic regions.
• The incidence of meningococcal disease is highest in the “meningitis belt” of sub-Saharan Africa (Map 2-6). The incidence of meningococcal disease is several times higher in the meningitis belt than in the United States, with periodic epidemics during the dry season (December–June). During nonepidemic 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 population.
• Serogroup A predominates in the meningitis belt, although serogroups C, X, and W-135 are also found.
• Young children have the highest risk for meningococcal disease.

Risk for Travelers

• Travelers to the meningitis belt may be at risk for meningococcal disease, particularly during the dry season.
• Risk is likely highest in travelers who will have prolonged contact with local populations in the meningitis belt during an epidemic.
• The incidence of meningococcal disease in international travelers who acquire sporadic disease is very low, estimated at 0.4 per 100,000 in one retrospective study.
• The Hajj pilgrimage to Saudi Arabia has been associated with outbreaks of meningococcal disease in returning pilgrims and their contacts.

Clinical Presentation

• Meningococcal disease generally occurs 1–14 days after exposure.
• Meningococcal disease presents as meningitis in 50% or more of cases. Meningococcal meningitis is characterized by sudden onset of headache, fever, and stiffness of the neck, sometimes accompanied by nausea, vomiting, photophobia, and/or altered mental status.
• Up to 20% of persons with meningococcal disease present with meningococcal sepsis. Meningococcal sepsis is characterized by an abrupt onset of fever and a petechial or purpuric rash. The rash may progress to purpura fulminans. Meningococcal sepsis may often involve hypotension, acute adrenal hemorrhage, and multiorgan failure.
• Among infants and children <2 years of age, meningococcal disease may have nonspecific symptoms. Neck stiffness may be absent.

Diagnosis

• 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 isolating N. meningitidis from blood or CSF, by detecting meningococcal antigen in CSF by latex agglutination, or by evidence of N. meningitidis DNA by polymerase chain reaction.
• The signs and symptoms of meningococcal meningitis are similar to those of other causes of bacterial meningitis, such as Haemophilus influenzae and Streptococcus pneumoniae. Identification of the causative organism is important for selecting the correct antibiotics for treatment and prophylaxis.

Treatment

• Invasive 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, chloramphenicol, cefotaxime, and benzylpenicillin.

Preventive Measures for Travelers

Vaccine

• ACIP recommends vaccination against meningococcal disease to persons who travel to or reside in countries where N. meningitidis is hyperendemic or epidemic, particularly if contact with the local population will be prolonged.
• Vaccination is advised for persons traveling to the meningitis belt of Africa during the dry season (December through June).
• Advisories for travelers to other countries will be issued when epidemics of meningococcal disease caused by vaccine-preventable serogroups are recognized (see the CDC Travelers’ Health website at www.cdc.gov/travel).
• Quadrivalent meningococcal polysaccharide–protein conjugate vaccine (MCV4) is licensed for use among persons 2–55 years of age.
• Quadrivalent meningococcal polysaccharide vaccine (MPVS4) is licensed for use among persons 2 years of age or older.
• Both vaccines protect against meningococcal disease caused by serogroups A, C, Y, and W-135. Approximately 7–10 days are required following vaccination for development of protective antibody levels.
• MCV4 is the preferred vaccine for persons 2–55 years of age; MPSV4 should be used for persons >55 years of age. There is no licensed vaccine for persons <2 years old, but MPSV4 is safe to give to children <2 years of age who require vaccination before traveling to Mecca for the Hajj pilgrimage.
• ACIP recommends that children previously vaccinated with MCV4 or MPVS4 at ages 2–6 years who remain at an increased risk for meningococcal disease should receive an additional dose of MCV4 three years after their previous meningococcal vaccine and every five years thereafter, if at continued risk. Likewise, persons who were previously vaccinated with MCV4 or MPVS4 at ages 7–55 years and who remain at an increased risk for meningococcal disease should receive an additional dose of MCV4 five years after their previous dose and every five years thereafter, if at continued risk.

Requirement for Travel

Proof of quadrivalent vaccination against meningococcal disease is required for persons traveling to Mecca during the annual Hajj and Umrah pilgrimage.

(This section has been updated as of October 15, 2009.)

Antibiotic chemoprophylaxis

• Antibiotic chemoprophylaxis among close contacts of a patient with invasive meningococcal disease is recommended for prevention of secondary cases in the United States and most industrialized countries.
• Antibiotic regimens for prophylaxis include rifampin, ciprofloxacin, and ceftriaxone. Ceftriaxone is recommended for pregnant women.

References

1. Raghunathan PL, Bernhardt SA, Rosenstein NE. Opportunities for control of meningococcal disease in the United States. Ann Rev Med. 2004;55:333–53.
2. Rosenstein NE, Perkins BA, Stephens DS, et al. Meningococcal disease. N Engl J Med. 2001;344(18):1378–88.
3. Greenwood B. Manson Lecture. Meningococcal meningitis in Africa. Trans R Soc Trop Med Hyg. 1999;93(4):341–53.
4. Stephens DS, Greenwood B, Brandtzaeg P. Epidemic meningitis, meningococcaemia, and Neisseria meningitidis. Lancet. 2007;369(9580):2196–210
5. American Academy of Pediatrics. Meningococcal infections. In: Pickering LK, ed. Red book: 2003 Report of the Committee on Infectious Disease. 26th ed. Elk Grove Village, IL: American Academy of Pediatrics; 2003. p. 430–6.
6. CDC. Prevention and control of meningococcal disease: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2005;54(RR07):1–21.
7. Koch S, Steffen R. Meningococcal disease in travelers: vaccination recommendations. J Travel Med. 1994;1(1):4–7.
8. Wilder-Smith A. Meningococcal disease: risk for international travellers and vaccine strategies. Travel Med Infect Dis. 2008;6(4):182–6.
9. CDC. Updated Recommendation from the Advisory Committee on Immunization Practices (ACIP) for revaccination of persons at prolonged increased risk for meningococcal disease. MMWR 2009;58:1042–3.