On Saturday 11th February 2012, the department of preventive medicine in Taif Directorate of Health Affairs reported 25 cases (out of 50 participants) complaining of gastrointestinal symptoms after eating a meal in a house of one of their relatives on Thursday, 09th February 2012 in Taif. The aim of this study is to identify the causative food and agent responsible for this outbreak.
Methodology
A case control study was conducted. An interview-based questionnaire was used to extract relevant information from cases and controls. A case was defined as any person who ate the lunch meal on 09th February, 2012 and developed one or more of the following gastrointestinal symptoms: abdominal pain, diarrhea, nausea, vomiting. Any personwho ate the same meal at the same time and did not develop any gastrointestinal symptoms was considered as a control. Environmental investigation was done and samples for laboratory investigations were obtained.
Results
A total of 50 persons (25 cases and 25 controls) were interviewed. 23 (92.0%) of the cases developed abdominal pain, 24 (96.0 %) developed nausea, 22 (88.0%) developed vomiting, while diarrhea appeared in 22 (88.0%) of the cases. A strong association between consuming unpasteurized animal milk and the appearance of symptoms was revealed (Odds Ratio = 36.4; 95% Confidence Interval = 6.57 - 201.7); laboratory results showed the presence of Staphylococcus aureus in the milk samples. Other food items did not show growth of any organism. Laboratory investigations of the patients(blood, stool and vomitus)were done for all patients and all were negative. The milk was extracted directly from goats, unpasteurized and kept at room temperature for one day.
Conclusion
Unpasteurized animal milk was the most likely implicated food item behind occurrence of this foodborne outbreak, and most likely Staphylococcus aureus was the responsible microbial organism.