The objective of this study is to find the proportion of locally acquired malaria cases among religious pilgrims to Makkah (Hajjees).
Methodology
A Cohort study (surveillance data) was conducted in Makkah Holy City, which population is usually about 600,000 people, and there is a fourfold increase during the Hajj (pilgrimage) season. Hajjees come from more than 140 countries. Participants in the study were all laboratory confirmed malaria cases diagnosed in Makkah Holy City during the Hajj season (February-March, 1998) identified by a special surveillance system. Recent travel history of case-patients was probed during face-to-face interviews. Intensive, environmental, malaria-control efforts were instituted in Makkah Holy City just before the Hajj season. The main Outcome Measure was identification of the most probable place for acquiring malaria.
Results
Out of 178 cases of malaria diagnosed during the Hajj season, 123 (69.1%) were due to Plasmodium falciparum, 49 (27.5%) P. vivax and 6 (3.4%) were due to mixed P. falciparum and P. vivax infections. Of all cases, 15 (8.4%) occurred among Hajjees. The onset of symptoms of 48 (27%) malaria patients started at or before arrival to Makkah. None of the cases could be attributed to local transmission of malaria inside Makkah Holy City. Case-patients included 126 (70.8%) Saudis who came to Makkah from other regions of Saudi Arabia where malaria transmission existed, including villages near Makkah (58 cases, 32.6%). However, 21 (11.7%) of the case-patients were diagnosed among recent arrivals from the Indian Subcontinent, 16 (9.0%) from East Africa, 13 (7.3%) from Yemen, and 2 (1.2%) from other countries.
Conclusion
Diagnosis of malaria cases among Hajjees during Hajj season does not imply local transmission of malaria in Makkah Holy City. Despite successful efforts made to interrupt local malaria transmission during Hajj season, the continuous influx of religious visitors and expatriate workers remains a potential source for introduction of malaria to the city of Makkah.