On Tuesday 4th of September 2012, the department of preventive medicine in Najran Directorate of Health Affairs was informed about a foodborne outbreak after reporting about 28 cases complaining of gastrointestinal symptoms. Those cases were complaining of abdominal pain, diarrhea, vomiting, nausea and / or fever, it was found out that they all ate from one of the public cafeteria on evening of Monday 3rd of September between 7-11 pm. Field Epidemiology Training Program (FETP) team investigated this outbreak, place was visited, environmental investigation was done, food samples were taken, the food handlers and the patients who still at the hospitals were interviewed.
Methodology
A case-control study was conducted. A questionnaire was used to extract relevant information from cases: any individual who ate the dinner meal from the involved cafeteria and developed any of the following symptoms: abdominal pain, diarrhea, vomiting and /or fever at the evening of the 3rd of September 2012. Any person who ate from the same cafeteria at the same time and had not developed any gastrointestinal symptom considered as a control.
Results
A total of 56 participants were interviewed. 28 were cases and 28 were control. Among cases, 28(100%) developed abdominal pain, 27 (96.4%) diarrhea, 20 (71.9%) fever, 23 (82.1%) nausea, 19 (67.8%) and 12 (42.8%) developed headache. A strong association between eating local prepared mayonnaise and the appearance of symptoms was revealed (odds= 50.0, 95% CI= 10.1 - 247.2). Laboratory investigations (blood, stool and rectal swab)for 8 patients were positive for salmonella.
Conclusion
Locally prepared mayonnaise was the most likely implicated food item behind occurrence of this foodborne outbreak, and most likelysalmonella was the responsible microorganism. A set of recommendations to avoid such outbreaks were generated.