A Five Site Clostridium Perfringens Food-Borne Outbreak: A Retrospective Cohort Study.

INTRODUCTION: In May of 2012, we investigated a food-borne Clostridium perfringens outbreak in Slovenia involving a single kitchen and five venues, with 477 exposed persons. METHODS: In order to identify the causative agent, vehicle of infection and source of contamination, we conducted microbiological and environmental investigations and an analytical cohort study (n = 138). RESULTS: The case definition in the outbreak was met by 104 persons. Predominant symptoms were diarrhoea, nausea and abdominal cramps. Median incubation time and duration of illness were 12 and 22.5 hours respectively. Stool samples were collected from 18 persons and in 13 C. perfringens spores were present; enterotoxin was detected in 9 persons. PCR and PFGE analysis of isolates from a cook with earlier onset time, who did not consume the implicated food, and cases from four venues showed the same strain of C. perfringens type A (with cpe-gene), indistinguishable by PFGE analysis. No food samples could be obtained. An analytical study showed that one food item (French salad) was the most likely vehicle of infection (RR: 6.35; 95% CI: 1.62-24.90). CONCLUSIONS: This was the largest C. perfringens outbreak in Slovenia to date. Proper analytical study in combination with detailed laboratory investigation with genotypisation enabled us to identify a causative agent, vehicle of infection and possible source of contamination. Fast response and interdisciplinary collaboration led to timely implementation of control measures. These have led to the kitchen acquiring new equipment and improving staff knowledge of risks and processes, thus reducing the likelihood of future reoccurrences.

Cryptosporidiosis associated with animal contacts.

Transmission of Cryptosporidium sp. within the general public was studied. We were looking for a possible risk of infection associated with animal contacts. Investigation of the animal contacts of affected individuals led to the formulation of the hypothesis that animals are a source of cryptosporidiosis. The research was done in the Region of Ljubljana, an area with 587,000 inhabitants during a period of three years. Stool specimens of 338 persons with acute enteric diseases were positive for Cryptosporidium sp. Diagnosis was done with an immunofluorescence test and modified Ziel-Neelsen staining. Processing of statistical data was done with the medical software application EPI INFO 6. According to our questionnaire, direct contact with animals occurred in 49 of the 338 cases of cryptosporidiosis, and was more frequently registered in males (Odds ratio = 1.96). Subgenotyping analysis revealed the presence of two subgenotypes of Cryptosporidium parvum bovine (GPB and GPC) in humans. These data indicate that genetic heterogeneity in C. parvum bovine genotype exists in a localized area and that farm animals can be a source of infection.