Cases have occurred at 19 restaurants or outlets. The oyster samples have been analysed and norovirus has been discovered in some of the samples. Norovirus has also been found in patient samples.
The persons who have had oysters have been in active contact with Helsinki’s Environmental Services. Further cases have not been reported, which we believe indicates an end to this outbreak.
The city will prepare an outbreak report for the Food Authority and the Institute of Health and Welfare. Everyone that fell ill will receive a written report of the matter.
If you think you have fallen ill after dining at a restaurant or eating a food product you purchased in a store, you can contact Environmental Services with our electronic food poisoning form. If a food business operator receives a food poisoning report from a customer, the operator is legally required to report it to their local food authority without delay. Reports are submitted at https://ilppa.fi(Link leads to external service).
Oysters are a risky food product
There are oyster-related food poisoning cases every year. Eating raw oysters always carries a risk, even though not all oysters are contaminated. Oysters can take in noroviruses if they live in water that is contaminated with human faeces. Flash heating may not be sufficient to eliminate norovirus. Heating to 90 degrees Celsius for two minutes is the requirement to eliminate a norovirus strain.
Restaurants are not capable of detecting the norovirus in an oyster. If the oysters have been contaminated with a norovirus, there is a risk that diners fall ill. The virus also spreads easily within families and other contacts.
