Purpose - An outbreak of food poisoning had occurred in Health Institute A on 1st June 2010 which involved twenty four staffs. Six of them were hospitalized and eighteen received outpatient treatment. A case control study was done to describe the epidemiological characteristics of the outbreak and to determine the source of infection.
Design/methodology/approach - Food samples, rectal swab from cases, environmental and hand swab from the food handlers were also taken and sent for microbiological analysis.
Finding- The outbreak was explosive, and the prominent clinical features were abdominal pain (62.2%), fever (51.4%), and diarrhea (56.8%). The onset time was between 9-24 hours and the median incubation period was at 15 hours. The possible source of the outbreak was durian gravy (OR= 14.00,95%CI: 2.72-92.55, p<0.001, food attack rate: 100%) and rotijala (OR= 6.69, 95%CI: LB5-24.23, p<0.001, food attack rate: 95%), The microbiological investigation revealed that various microorganisms including Salmonella spp, The food was supplied by the same food supplier from Caterer B since 2006 and the assessment of the kitchen showed that the cleanliness rate was only 54,3% with positive results of Coliform in all utensils and areas investigated in the kitchen.
Conclusion- In conclusion, the most probable causative organism based on signs and symptoms, epidemiological analysis and microbiological results was Salmonella spp. from contaminated food seryed during the ceremony. Education on food safety and food hygiene especially personal hygiene and hand washing should be emphasized continuously for prevention of future outbreak,