Hajj is one of the central religious duties of Islam; drawing millions of Muslims from around the world to Saudi Arabia. The occurrence of meningococcal disease outbreaks during Hajj has been noted in previous studies. The surveillance system in Makkah, Madinah and Jeddah detected successive cases of meningococcal disease among Hajj pilgrims as well as Saudi residents during Hajj 1420 H. We report the extent of this meningococcal disease outbreak and the epidemiologic characteristics of meningococcal disease cases.
Methodology
We reviewed the case investigation forms of all confirmed cases of meningococcal disease at Makkah, Madinah and Jeddah Health Directorates. Then we reviewed the medical records of all bacteriologically confirmed cases of meningococcal disease admitted to Makkah, Madinah and Jeddah hospitals between l7 Shawwal 1420 to 28 Safar 1421H.
Results
There were 264 cases of meningococcal disease diagnosed at Makkah, Madinah and Jeddah cities. This outbreak is unique insofar as it was composed of two concurrent outbreaks: one serogroup A and one serogroup W135. Of these, 253 (96%) were laboratory confirmed. l6l cases (64%) had serogroup identification: 93 cases (37%) of total disease were caused by serogroup W135 and 60 (24%) by serogroup A. Serogroup A and serogroup W135 attack rates were estimated at 6 and 9 cases/100,000 population, respectively.
Conclusion
The magnitude of the 1420 serogroup A outbreak was less than one-tenth that of the 1407 outbreak, which could be attributed to meningococcal vaccination (bivalent serogroup A/C polysaccharide vaccine) that was made mandatory for all Hajj attendees by the government of Saudi Arabia since 1988. In contrast, the 1420 serogroup W135 outbreak is the largest yet reported worldwide, which could be explained by low vaccination coverage against serogroup W135. Mandatory vaccination of pilgrims and Saudi residents with the Quadrivalent meningococcal vaccine (A/C/Y/W135) is imperative to prevent further outbreaks.