Description

Meningococcal disease is an acute bacterial disease characterized by sudden onset with fever; intense headache; nausea and often vomiting; stiff neck; and, frequently, a petechial rash with pink macules. Formerly, case-fatality rates exceeded 50% but, with early diagnosis, modern therapy, and

supportive measures, the case-fatality rate is now from 5% to 15%. Up to 10% of populations in countries with endemic disease might be asymptomatic carriers.

Occurrence

In sub-Saharan Africa, epidemics of serogroup A or C meningococcal disease occur frequently during the dry season (December through June), particularly in the savannah areas extending from Mali eastward to Ethiopia, known as the "meningitis belt" (see Map 3-5).

Risk for Travelers

Meningococcal disease in Americans traveling in sub-Saharan Africa is rare. However, because of the lack of established surveillance and timely reporting from many of these countries, travelers to the meningitis belt during the dry season should be advised to receive meningococcal vaccine, especially if prolonged contact with the local population is likely.

Preventive Measures

Vaccine

Vaccination against meningococcal disease is not a requirement for entry into any country, except to Mecca, Saudi Arabia, for travelers during the annual Hajj. Vaccination is indicated for travelers to countries recognized as having epidemic meningococcal disease caused by a vaccine-preventable serogroup (that is, A, C, Y, and W-135). Advisories for travelers to other countries will be issued when epidemics of meningococcal disease caused by vaccine-preventable serogroups are recognized. (See the Centers for Disease Control and Prevention [CDC] Travelers' Health website http://www.cdc.gov/travel.)

Serogroup A is the most common cause of epidemics outside the United States, but serogroup C and serogroup B can also cause epidemic disease. One formulation of meningococcal polysaccharide vaccine is currently available in the United States: quadrivalent A, C, Y, and W-135 vaccine (Table 3-11). The vaccine is available in single- and multiple-dose vials, and is distributed in the United States by Aventis Pasteur. No vaccine is yet available to offer protection against serogroup B. Meningococcal vaccines are chemically defined antigens consisting of purified bacterial capsular polysaccharides, each inducing serogroup-specific immunity. Serogroup A vaccine has not been shown to be effective in infants younger than 3 months of age and can be less than fully effective in infants 3 through 11 months of age. Serogroup C vaccine has not been shown to be effective in infants younger than 2 years of age. The group Y and W-135 polysaccharides have been shown to be safe and immunogenic in adults; the response of infants to these polysaccharides is unknown.

Table 3-11.--Meningococcal Vaccine. Type of Vaccine Dose Comments
Quadrivalent A,C,Y,W-135 0.5 milliliter Duration of immunity is unknown, but appears to be at least 3 years in those 4 years of age or older. Revaccination after 2 to 3 years should be considered for children first vaccinated before 4 years of age who continue to be at high risk.
For subcutaneous injection.

Adverse Reactions

Adverse reactions to meningococcal vaccine are infrequent and mild, consisting principally of localized erythema that lasts 1 to 2 days. Up to 2% of infants develop fever transiently after vaccination.

Precautions and Contraindications

Studies of vaccination during pregnancy have not documented adverse effects among either women or neonates (1 month of age or younger). Based on data from studies involving the use of meningococcal vaccines and other polysaccharide vaccines administered during pregnancy, altering meningococcal vaccination recommendations during pregnancy is unnecessary.

© Center for Disease Control

Credits: National Center of Infectious Diseases