MANAGING OF THE OUTBREAK OF STAPHYLOCOCCAL FOOD POISONING IN PRIMARY SCHOOL

Background: In October 2010 an outbreak of staphylococcal food poisoning occurred in an elementary school with a kindergarten in Gorenjska. Methods: Using a questionnaire we performed a retrospective cohortanalytical epidemiological study. We calculated attack rate (AR) and relative risk for each food item. In patients we cultivated stools and vomit. We performed an onsite audit where the food samples, environmental samples, and swabs of the hands of the cooks were taken. We performed medical examination of those employed in the kitchen where specimens were taken for microbiological examination. Staphylococcal enterotoxins were detected with agglutination test SET RPLA (Oxoid) and genotypes determined by the pulsed-field gel electrophoresis (PFGE). Results: Out of 374 exposed 73 subjects got ill. Attack rate in the outbreak was 19,5 %. The most frequent symptoms were vomiting (87,7 %), stomach ache (75,3 %), diarrhea (64,2 %) and nausea (59,3 %). The highest relative risk (RR) were found for the meatloaf (RR=24,2 (95 % CI 12,1-48,5; p<0,001)) and potato salad (RR= 19,4 (95 % CI 10,7 - 35,2; p<0,001)). Enterotoxin A producing S. aureus was isolated from hand of a cook, from potato salad and meatlof, from vomit and stools of patients. These strains had the same antibiotic sensitivity and were genetically closely related (96,3 %). Conclusions: In the article an optimal team approaches of a community epidemiologist and microbiologist in the occasion of outbreak are described. We confirmed epidemiologically related isolates and determined the importance of individual methods.