Makkah is the holiest city of Islamic religion. Each year ten million Muslims visit it for pilgrimage, hajj and umrah. During such mass gathering events, there is a higher risk of communicable diseases especially airborne and foodborne. Many food poisoning outbreak incidents occurred in Makkah during hajj and umrah seasons. Field Epidemiology Training Program (FETP) sent a team to investigate a possible food poisoning outbreak among Algerian pilgrims. the team decided to conduct a case-control study to identify the extents of the incident and to specify the main cause of food poisoning.
Methodology
Case-control study using a self- administered questionnaire among Algerian umrah pilgrims staying at Nukhbat Almuabedah hotel, Makkah at the date of the incident, 8th of Ramadan 1437 H. After data collection, entry and cleaning, descriptive analysis was done to measure means, standard deviations and frequencies. Attack rates and odd's ratio of each food's item has been calculated and epidemic curve has been drawn.
Results
The number of those who ate the breakfast meal served inside the hotel in 8th of Ramadan 1437 H reached 133 persons. the total number of cases to 104 while the controls were 29 persons with an attack rate of 78.2%. The mean age (STD) of the study population was 49.3 (18.1) years. Most of the study population had their meal at 7:00-8:00 pm. The peak of the cases was at 4:00 am-12:00 pm, next day. The most common symptoms among cases were diarrhea (99.0%), abdominal pain (85.6%) and fever (80.0%). Among the food's items, chicken with potatoes, which was eaten by 95.2% of the cases, has the highest attack rate (79.8%) and the highest odd's ratio (3.2) with almost significant p-value (0.06).
Conclusion
Epidemic curve showed that the incubation period is 9-17 hours. Results showed that chicken with potatoes has the highest attack rate and odd's ratio among the other food's items with almost significant p-value (0.06) due to low number of controls in comparing to cases. However, results still suggest its contamination and being the possible cause of the food poisoning outbreak. Contamination of eggs, which were used to prepare the sauce of chicken with potatoes, has been identified as one of the major causes of foodborne Salmonella. Moreover, three stool cultures came with positive results to Salmonella.
The food's preparation process, the findings of the case-control study and the laboratory's results suggest that the Salmonella-contaminated chicken with potatoes is the possible cause of this food poisoning outbreak.