Meningitis in Makkah, January-April 1997

The Makkah Health Directorate routinely vaccinates residents against meningococcal meningitis with meningococcal vaccine (MCV). Since 1988, all religious visitors for the Hajj, the annual Islamic pilgrimage, have been required to produce a certificate of vaccination against meningococcal disease (MCD) issued not more than three years and not less than 10 days before arrival in Saudi Arabia [1,2,3]. However, in 1997, the surveillance system in Makkah detected successive cases of MCD among religious visitors during Ramadan. a holy month for Muslims.

In addition to an activated surveillance system and prompt reporting, primary health care centers (PHCCs) in densely populated quarters of Makkah thought to be inadequately covered with MCV (for serogroups A and C) set up visible mobile vaccination teams that provided free MCV inoculations in their catchment areas. These districts were predominantly inhabited by residents and/or religious visitors from Sub-Saharan Africa (the "meningitis belt"), South Asia and Turkey. The employees of major governmental institutions were also vaccinated. Chemoprophylaxis (a single dose of ciprofloxacin 500mg) was given to all household contacts of MCD patients. Patients seen at the PHCCs and the outpatient departments at Makkah hospitals were advised to be vaccinated with bivalent MCV; and MCV against group A MCD was temporarily incorporated into the routine childhood vaccination program for children aged three months to two years. MCV was made a prerequisite for renewal of health certificates of food handlers, issuance of passports to Saudis, renewal of residency permit (iqama) of non-Saudis and for other transactions at the Immigration Department; vaccination teams were located at City Hall and the Immigration Department to facilitate this activity.

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.

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 four kilometers away from Haram, and more than four 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.

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°/0-78.0%) 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 not important (6.2%), and being told that vaccinations would be given in Saudi Arabia (1.5%); 24.9% gave no reason.

The occurrence of MCD outbreaks during the period between Ramadan and Hajj lunar months (a three-month interval) has been noted in previous studies [1].

Although the vaccination coverage with MCV was relatively higher among international religious visitors than domestic religious visitors, more than two-thirds of the MCD cases occurred among international religious visitors. This is because the total number of religious visitors was about triple the number of residents of Makkah during the Hajj season. Such vaccination coverage rates would make the number of unvaccinated international religious visitors more than double the number of unvaccinated domestic religious visitors. Unfortunately, we were not able to calculate nationality-specific attack rates due to lack of data needed for denominators (i.e., the number of pilgrims from each country).

The vaccination coverage with MCV could be increased by intensified health-education programs, as a sizable proportion of Makkah residents and religious visitors were ignorant about MCD, its serious complications and availability of a safe and efficacious vaccine. About one-fourth of those who were not vaccinated stated that they could not do so because they had no time to go to the nearest health center for vaccination against MCD. Accordingly, provision of vaccination services to the public through mobile vaccination teams would be beneficial.

The majority of MCD cases were Pakistani and Turkish religious visitors. Vaccination of international religious visitors who could not show a valid MCV certificate at airports and seaports is recommended and would be cost-effective. Religious visitors from certain nationalities, especially those from areas known to have been affected with outbreaks of MCD, would require some special additional efforts.