On Monday 14 may 2007 at about 10:00P.M. About 70 persons attended a reconciliation banquet in a house in Riyadh city. Next day, 50 of them started to complain of diarrhea, abdominal pain, fever, nausea, vomiting, chills, and headache with some variations in symptoms and severity. 25 of them visited emergency departments in different hospitals in Riyadh city. This was notified to the on-call center which was the northern PHCC in Al-naseem district. An investigation was initiated to identify the source, mode of transmission and etiologic agent standing behind this outbreak.
Methodology
A retrospective cohort study was conducted. The data was collected via telephone calls with some cases and non-cases to inquire about food items they had, symptoms they experienced, either hospitalized or not, the management they received and the laboratory results if available. Anyone of the attendees developed one or more of the following symptoms (diarrhea, vomiting, abdominal pain and/or fever) within two days of the banquet was considered as a case.
Results
A total of 29 individuals were contacted,18 developed gastroenteritis manifested by diarrhea (100%), abdominal pain (88.9%), fever (88.9%) and vomiting (77.8%). All were Saudis; (62%) males and (38%) females. The median incubation period was 10.30 hours. The most probable implicated food items are aum ali (sweet) and green salad from the restaurant. Regarding aum ali(sweet) (R.R=1.93) with 95% C.I=1.06-3.53. Regarding green salad (R.R=1.85) with 95% C.I =1.28-2.67. salmonella-D was isolated from 5 cases belonging to family of banquet host.
Conclusion
Salmonella-D was considered the causative agent whereas aum ali (sweet) and green salad from the restaurant were the most likely incriminated food items. The source of infection is likely family of banquet host.