The role of infected food handlers in two norovirus outbreaks in Spain has recently been highlighted by researchers.
In 2018, two cases of gastroenteritis occurred one week apart at the same facility in Lleida, Spain. The most frequent symptoms were abdominal pain, vomiting, and nausea.
The first outbreak was associated with the consumption of a salad, and the second with a cheese omelet.
Norovirus was found to have been detected by RT-PCR and sequenced in both the student group and the food handlers preparing the meals. journal scientific report.
First occurrence details
In April 2018, the Epidemiological Surveillance Department of Lleida, Alto Pirineu and Aran received a report of a possible outbreak of acute gastroenteritis in a group of students from a high school in Lleida who were attending a holiday camp house. A week later, a second outbreak was reported at the same facility, affecting a different group at the same school.
The first outbreak with 19 patients was reported 2 days after arrival on scene. The second outbreak reported 12 cases. There were two people in charge of meals at the camp house.
In the first outbreak, 29 studies involving 32 group members were analyzed, with 26 developing symptoms. The students were 12 and 13 years old, and the three teachers were between 43 and 53 years old.
When the exposure time point was fixed at the time of salad consumption, the incubation period for the 22 cases was calculated as a median of 31 hours and a range of 27 to 46 hours. Virological analysis detected norovirus in five fecal samples taken from patients. A sample of the salad was analyzed and came back negative.
The first teacher presented with symptoms of acute gastroenteritis the day before the first school group arrived, and the second teacher presented with symptoms of acute gastroenteritis the day after arrival. Fecal samples from both were negative.
Discovery of second outbreak
In the second outbreak, 23 investigations were analyzed and 16 people became ill. The ages of the respondents were 12 and 13 years old.
When the source of exposure was omelet consumption, the incubation period for the 15 patients was a median of 28 hours, with a range of 16 to 49 hours. Norovirus was detected in four stool samples from the patient. It was not possible to analyze the cheese omelet.
Fecal samples from both food handlers tested positive for norovirus. An inspection after the second outbreak found that, like the previous visit, there were no soap dispensers or paper towels in the bathroom sink or in the kitchen hand-washing area. They also failed to follow guidelines for disinfectants used to clean surfaces, and were asked to come into the office to disinfect the kitchen and restrooms.
Researchers said food handlers with symptoms of gastroenteritis should not return to work for up to 48 hours after symptoms have subsided to avoid consecutive outbreaks within the same facility.
“It is also necessary that appropriate equipment for proper hand washing (soap dispensers and hand dryers) be available everywhere. “This highlights the importance of proper handwashing and access to appropriate mechanisms for cleaning surfaces,” the researchers added.
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