Infected food handlers continued working in a large norovirus outbreak in Spain in 2021, according to a study. 

In the summer of 2021, an outbreak of norovirus affected 163 patients, including 15 norovirus-confirmed food handlers, in a hotel in Murcia, southeast Spain. A similar norovirus outbreak occurred at the same hotel in 2019.

The epidemiological investigation of the latest incident revealed that norovirus transmission might have been initiated through an infected food handler. A food safety inspection found that some symptomatic food handlers continued working during illness.

In July and August 2021, an outbreak was reported in a hotel in Murcia. A rare norovirus strain was identified as the cause. The regional public health department and food safety authority investigated to identify the source and implement control measures.

In total, 163 cases were reported: 156 clients and seven food handlers. The age range of patients was 2 to 74 years old while more women were sick than men.

No patients were hospitalized. All but one had full board; meaning they were living and having meals inside the hotel, according to the study published in the journal Microbiology Spectrum.

The first infections occurred in July and involved a probable symptomatic client and a symptomatic laboratory-confirmed food handler. The next day, five food handlers reported gastrointestinal symptoms, supporting the hypothesis that they could have contributed to the initial spread of the virus.

The outbreak might have been further spread by person-to-person contact and direct contact with contaminated surfaces, said researchers.

Importance of not working when sick
A few days after it was found that some staff continued working during illness, all food handlers were stopped temporarily from their duties. In early August, the hotel closed the kitchen and all food and drink services but two weeks later additional cases were reported.

A study looking at food items served at the hotel’s restaurant was conducted to identify the source of infection. It included 65 probable primary cases and 14 controls who completed the questionnaire, but no specific food was associated with illness.

A total of 17 stool samples from symptomatic and asymptomatic food handlers and symptomatic clients were positive for norovirus.

“Although the specific source of this outbreak remains unclear, based on the epidemiological investigation, norovirus transmission might have been initiated through food that had been manually handled by an infected food handler,” said researchers.

“This emphasizes the importance of the immediate exclusion of symptomatic food handlers, adherence of symptomatic food handlers to work exclusion rules, strict hand hygiene practices, and decontamination of environmental surfaces to prevent contamination of food items.”

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