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During late March and early April 2000, four cases of meningococcal disease caused by Neisseria meningitidis serogroup W-135 were identified among U.S. pilgrims returning from the Hajj in Saudi Arabia, their close contacts, and communities.1 These cases occurred as part of a larger epidemic in which approximately 400 cases caused by a similar and unusual strain were identified worldwide.2 The Hajj, an annual pilgrimage to the major holy places of Islam, is attended by approximately two million persons from approximately 140 countries, including an estimated 15,000 from the United States.
After an outbreak of serogroup A meningococcal disease in 1987 associated with the Hajj, CDC recommended that U.S. pilgrims receive the quadrivalent meningococcal polysaccharide vaccine.3 This vaccine provides protection against disease caused by serogroups A, C, Y, and W-135; however, the vaccine may not affect asymptomatic pharyngeal carriage or a person's ability to transmit disease. To assess the risk for meningococcal disease in 2001 among U.S. pilgrims, CDC conducted a study of pharyngeal carriage of N. meningitidis in departing pilgrims traveling to Saudi Arabia and of passengers returning from Saudi Arabia after the Hajj 1-2 weeks later.
After informed consent was obtained, pilgrims departing from John F. Kennedy International Airport (JFK), New York, on seven consecutive direct flights to Saudi Arabia during February 16-27, 2001, were asked to complete a questionnaire and provide an oropharyngeal swab for culture. During March 9-16, all disembarking passengers (i.e., pilgrims and nonpilgrims) on five consecutive direct flights from Saudi Arabia to JFK were similarly approached; 451 pilgrims were enrolled in the departing portion of the study and 869 passengers, including 727 pilgrims, were enrolled in the returning portion. Of the 27 N. meningitidis isolates recovered from1320 passengers, 17 (63%) were nongroupable (i.e., a typically nonpathogenic strain); seven (26%) were serogroup W-135. Returning pilgrims were more likely to be carriers than departing pilgrims (2.6% versus 0.9%; p = 0.04). None of the departing pilgrims carried serogroup W-135; however, six (0.8%) returning pilgrims were serogroup W-135 carriers (p = 0.06). Among returning passengers, carriage of serogroup W-135 was similar among pilgrims and nonpilgrims (0.8% versus 0.9%; p = 0.98).
Many returning passengers reported upper respiratory symptoms; 63% reported cough, 58% had sore throat, and 24% had fever during the 2 weeks before their return. Antibiotic use was reported by 396 (49%) of 811 returning passengers and was associated with decreased (although not significantly [2.1% versus 4.2%; p = 0.09]) N. meningitidis carriage. The cause of this illness is not known; severe illness requiring hospitalization was not reported.
Because of the low rate of N. meningitidis serogroup W-135 carriage, antimicrobial chemoprophylaxis for all pilgrims returning to the United States is not recommended. Although overall carriage was low, the high proportion of serogroup W-135 carriage suggests continuing transmission in Saudi Arabia. Evidence of this transmission, combined with reports of cases of invasive disease among pilgrims returning to the United Kingdom who received only bivalent vaccine against serogroup A and C, suggests that U.S. pilgrims should continue to receive quadrivalent meningococcal polysaccharide vaccine before travel to the Hajj.
Div of Applied Public Health Training, Epidemiology Program Office; Meningitis and Special Pathogens Br, Div of Bacterial and Mycotic Diseases; Surveillance and Epidemiology Br, Div of Quarantine, National Center for Infectious Diseases; and EIS officers, CDC.
Update: Assessment of Risk for Meningococcal Disease Associated With the Hajj 2001. JAMA. 2001;285(15):1956. doi:10.1001/jama.285.15.1956-JWR0418-3-1