On Saturday April 8, 2000, twenty one people presented at two hospitals in Hail, King Khalid and Hail General Hospitals with complains of abdominal pain, nausea, vomiting, and diarrhea after eating from a bakery. All the patients gave a history of eating food from "Kaream bakery and confectionary" in the commercial area of Hail city. The investigation aimed to identify the source of the outbreak and recommend control measures for prevention of a similar situation in the future.
Methodology
A case was defined as any person who ate food from "Kaream bakery and confectionary" on Friday April 7, 2000, and developed one or more of the following symptoms: nausea, vomiting, diarrhea, abdominal pain, fever, between Friday April 7 2000 and Saturday April 8 2000. All the cases were interviewed and asked about food history and symptoms through a questionnaire. Laboratory results of samples collected from patients, bakery workers and food items were obtained. A case-control study was conducted to implicate food items, the odds ratios (OR), 95% confidence interval (CI) and P-value were calculated.
Results
A total of 50 people were interviewed; 25 cases and 25 controls. Four cases were further identified through active case finding. Ninety two percent of cases complained of vomiting, Eighty four percent complained of nausea and Eighty percent complained of abdominal pain and diarrhea. The falafel sandwich was implicated (OR 9.33, P value < 0.02). The illness developed between 6 and 8 hours after eating. Staphylococcus aureus was isolated from the workers responsible for preparation of falafel sandwiches and from the vomitus of 2 cases. It was found that the falafel sandwiches had been stored at room temperature and one of the two workers responsible for preparation of falafel sandwich had a healing abscess in his right finger of 4 days duration.
Conclusion
The clinical, epidemiological, and laboratory investigation of this gastroenteritis outbreak showed that the organism causing this problem was probably Staphylococcus aureus. Poor unsafe handling could have resulted in over growth of bacteria. It was recommended that food handlers with infected lesions should not handle food, and susceptible food items should be kept refrigerated at all times except during preparation and serving.