Religious visitors to Makkah, Saudi Arabia, have to be vaccinated against meningococcal disease (MCD). However, in 1997, the surveillance system in Makkah detected successive cases of MCD among religious visitors during Ramadan, a holy month for Muslims. We report the extent of the MCD outbreak, the epidemiologic characteristics of MCD cases, and the vaccination coverage with meningococcal vaccine (MCV) among the population of Makkah.
Methodology
We reviewed the medical records of all bacteriologically confirmed cases of MCD admitted to Makkah hospitals. We divided Makkah into three geographical zones: immediately around the Haram (the Holy Mosque) within 500 meters, 500 meters to 4 kilometers away from Haram, and more than 4 kilometers from the Haram. A total of 32 clusters were randomly selected, and seven neighboring houses or apartments were selected following a random start of the first house. Up to 10 people were interviewed to ascertain their vaccination histories.
Results
There were 51 confirmed cases of MCD from 15 countries (40% were Pakistani). Mean age was 48 years (range 6-83). Of patients, 70.6% were religious visitors, 25.5% were non-Saudi residents of Makkah and 3.9% were Saudis. The case-fatality rate (CFR) was 27.5%, and the CFR did not differ with the residency status. Pakistanis accounted for 50% of deaths. The survey (sample size = 707 persons) showed that the overall coverage with MCV within the last three years was 74.8% (95% CI 71.4%-78.0%) compared with 29.4% among cases. The MCV vaccine efficacy was 84% (95% CI 70%-93%). The vaccination coverage percent was 87.1% (95% CI 78.6%-92.7%) for religious visitors, 76.4% (95% CI 72.0%-80.4%) for non-Saudi residents, 69.9% (95% CI 61.6%-77.2%) for Saudi citizens, and 48.9% (95% CI 34.3%-63.7%) for illegal aliens. The highest vaccination coverage was found in sub-Saharan Africans (79.5%; 95% CI 69.3%-87.1%) and the lowest among Southeast Asians (56.9%; 95% CI 42.3%-70.4%). The vaccination coverage percent for the three geographical zones around the Haram decreased from 79.4% (95% CI 73.8%-84.1%) in the area that lies within 500 meters from Haram to 69.4% (95% CI 62.1%-75.8%) in the areas four kilometers or more from Haram. The reasons for not being vaccinated included not knowing about the disease (42.5%), being too busy to go to a health center (24.9%), considering vaccination as not important (6.2%), and being told that vaccinations would be given in Saudi Arabia (1.5%); 24.9% gave no reason.
Conclusion
The moderately high efficacy of MCV makes it a powerful tool against MCD. Although all visitors to Makkah need to be educated about the seriousness of the disease, certain nationalities probably require special additional efforts.