In April 8, 2000, Samta General Hospital received 13 cases from two families showing symptoms of gastroenteritis. They gave a history of eating common food at Aldagarir restaurant that located on the main road 10 km away from Samta Hospital. They were complaining of abdominal pain, nausea, vomiting and diarrhea. All the cases were admitted to the hospital, received treatment, improved and discharged on the next few days.
Methodology
A case control study was conducted. A case was defined as any individual who ate from Aldagarir restaurant on April 8, 2000 and had developed abdominal pain, and/ or diarrhea and vomiting. The cases were interviewed and every food items consumed was determined. Odds ratio were calculated along with 95% confidence interval for each food item. Stool samples and vomitus of the admitted patients were cultured. Restaurant workers were interviewed to obtain information on the food menu, and methods of food storage and handling at the restaurant.
Results
The cases belonged to 2 different families; most of them were small children. Four additional cases were found, yielding a total of 17 cases; 6 males (35.3%) and 11 females (64.7%). Cases were between 1 to 41 years of age, 11(64.7%) were below 10 years old (median age =9). They developed symptoms within 2 to 3 hours of eating the meal. Symptoms were abdominal pain 100%, vomiting 82%, Nausea 76%, diarrhea 76%, fever 35%. The food item they reported eating were chicken, rice, salad, mosagaa, marsa. The only food item incriminated as a cause of the outbreak was chicken (odds ratio 10.96, 95% CI 1.84-84.79, P-value < 0.001). Stool and vomitus culture showed that 5 cases were positive for Yersinia entercolitica. Furthermore, the stool cultures of the restaurant workers were positive for salmonella.
Conclusion
This outbreak is probably due to poor storage and handling of chicken at the restaurant. Although stool and vomitus culture of the cases were positive for Yersinia entercolitica in 5 cases, the clinical presentation and the epidemiological investigation were not compatible with this diagnosis. We therefore believe that the cause of this outbreak was either Staphylococcus aureus or Bacillus cerius, both of which could not be proved by laboratory investigation.