Almost 40 people fell ill with norovirus in August in a region of Ireland. Authorities say some were sickened by contaminated food.

Data from the Health Protection Surveillance Centre’s (HPSC) weekly outbreak report shows 36 illnesses from noroviral infection in the Dublin East region for the notification period from Aug. 25-31.

The outbreak location is described as “other” and the source of some infections are foodborne while others have person-to-person transmission.

The Health Protection Surveillance Center is Ireland’s agency for the surveillance of communicable diseases and is part of the Health Service Executive (HSE).

Outbreak over

A spokeswoman for the HSE told Food Safety News the outbreak had ended and an investigation was progressing but no further information would be released.

“While the outbreak is over there is an investigation currently ongoing, therefore, there is no further information available at this time. However, it is expected that a report will be available on conclusion of the investigation,” she said.

The spokeswoman added she didn’t have an exact date for when this report would be available.

Noroviruses are one of the most common causes of gastroenteritis. There were 1,329 norovirus notifications in Ireland in 2017. Provisional data shows 18 outbreaks with 271 people ill in the first quarter of this year.

Foods commonly involved in norovirus outbreaks include leafy greens such as lettuce, fresh fruits, and shellfish such as oysters. The infectious dose is very small and noroviruses are shed for at least two weeks after gastroenteritis. There is usually a peak of infections in winter.

Norovirus is a highly contagious virus that frequently spreads person-to-person and is often associated with food. Typical symptoms of infection are quick onset of vomiting, watery, non-bloody diarrhea with abdominal cramps, nausea and dehydration, with the latter being the most common complication. Symptoms usually begin 24 to 48 hours after infection and last for 12 to 60 hours. No vaccine is available.

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