Pharyngeal carriage of serogroup W135 Neisseria meningitidis in Hajjees and their family contacts in Morocco, Oman and Sudan
In 2000 the global outbreak that began in Saudi Arabia was caused by a W135:2a:P1.5,2 strain of Neisseria meningitidis belonging to the ET-37 complex and to ST-11. There was concern that introduction of this epidemic clone (EC) might lead to a wave of outbreaks in the African meningitis belt. The WHO therefore initiated studies of meningococcal carriage among pilgrims and their family contacts in Morocco, Oman and Sudan, 3 to 12 months after the Hajj 2000. In Morocco, 1186 persons were swabbed 3 times. Ninety-five meningococcal strains were isolated from 2.7% of the specimens. Pulsed-field gel electrophoresis showed that 32 (33.6%) were identical with the EC. In Sudan, 5 strains identical with the EC were obtained after sampling 285 persons. In Oman, among 18 meningococcal strains isolated from 399 subjects, 11 (61.1%) belonged to the EC. The important pharyngeal carriage of W135 (EC) and its role in the 2001–2002 outbreaks in Burkina Faso argues for the necessity of reinforcing surveillance, and adapting and planning responses in Africa and the Middle East using the most appropriate vaccine.
Keywords: Neisseria meningitides; clonal complex; meningococcal meningitis; meningococcus; molecular epidemiology; multilocus sequence typing; pulsed-field gel electrophoresis; sequence type; serogroup W135
Document Type: Research Article
Affiliations: 1: Institut National d'Hygiène, Rabat, Morocco 2: Department of Surveillance & Disease Control and 3: Central Public Health Laboratory, Muscat, Oman 4: National Health Laboratory, Khartoum, Sudan 5: Epidemiologie et lutte contre les maladies, Ministère de la Santé, Rabat, Morocco 6: National Reference Laboratory for Pathogenic Neisseria, University Hospital, Örebro, Sweden 7: WHO Collaborating Centre for Reference and Research on Meningococci, Norwegian Institute of Public Health, Oslo, Norway 8: Communicable Diseases Surveillance and Response, WHO, Geneva, Switzerland
Publication date: 01 March 2005