A suspected Clostridium perfringens outbreak affected 30 people in Greece in 2021, according to a study.

In May 2021, several gastroenteritis cases were reported among students and staff of a high school on a Greek island. Daily hot lunches were delivered by a catering company and consumed in classrooms.

In late May, the Hellenic National Public Health Organization was informed by a regional unit of the Hellenic Food Authority (EFET) about a cluster of gastroenteritis cases among 12 to 18-year-old students and teachers. The school is in a small town on a remote north-eastern Aegean Greek island, which had limited capacity for specific laboratory testing.

Patient and food sampling
Based on a questionnaire, researchers received 129 responses from students and staff and 30 patients were identified, of which four were teachers. Sixty percent of cases were women, and the median age was 13 with a range of 12 to 40 years old.

Most sick people had abdominal pain and diarrhea, while 19 reported fatigue. The median duration of symptoms was a day, with a maximum of three days, and no one was hospitalized. 

Of 11 significant food items in the analysis, the consumption of spaghetti with the ground (minced) meat was associated with the onset of gastroenteritis, as found in the study published in the journal Foodborne Pathogens and Disease.

Clostridium perfringens were detected in two of three students’ stool samples. Six samples from spaghetti with ground meat were positive for Clostridium perfringens and four also tested positive for Bacillus cereus. The whole intact prepacked meals were found in the school’s refrigerator and were part of the meal offered the previous day, just before the occurrence of cases.

Investigation of Clostridium perfringens toxins in clinical and food samples was not performed due to a lack of laboratory capacity, so the pathogen behind the outbreak was not confirmed.

Food sampling and further inspection of the two involved facilities were conducted by the EFET-Regional Directorate of the North Aegean Sea. The first was the school where meals were delivered and the second was the establishment where food was previously produced.

Investigations at the school and caterer
Deficiencies in the reception and distribution of meals, by the catering company and the receiving committee at the school, were identified. The mass caterer did not accurately describe the type of lunch dishes in the delivery notes and the temperature of the meals was not checked on the receipt.

It was not specified whether the time elapsed between the preparation and consumption of lunch meals at the school was under two hours.

Environmental investigation revealed non-compliance around food personnel training and Hazard Analysis and Critical Control Points (HACCP) plan implementation in the food establishment. 

Raw ground meat was supplied, marinated, blanched, and frozen in a blast freezer until further cooking five days later. Then, the spaghetti was cooked and mixed with ground meat, transported, and served at the school.

After being cooked, meals were packed in individual portions and put into a hot holding chamber. They were temporarily stored until all portions were ready to be loaded in the transport vehicles and placed in isothermal boxes.

Although the temperature of the chamber was meant to be 75 degrees C (167 degrees F), during the investigation it was around 55 degrees C (131 degrees F).

No other outbreaks were linked to the catering company. Part of the same ground meat batch was prepared and served a few days later elsewhere, with no issues reported, suggesting there was mishandling during the production of the meals or their distribution to the school, found the study.

Changes to reception and distribution of meals in the school were applied. Recommendations to the catering establishment covered adequate employee training and HACCP issues, especially regarding temperature/time controls during all production, handling, and distribution stages.

Lab capacity to detect bacterial toxins in the country and implementation of food safety measures in school settings should be strengthened, said researchers.

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