It is important to note that eating raw oysters is always a risk, even if not all oysters are contaminated. Oysters filter and collect norovirus from feces-contaminated water, which is a risk for human consumption. Rapid heating does not necessarily destroy the virus, as the virus is destroyed when the food is heated to +90 degrees for two minutes.
Restaurants cannot detect norovirus in oysters. Thus, if the oysters are contaminated with Norovirus, diners can get sick and the virus can spread easily in families and other contacts.
A report on the epidemic is submitted to the Food Agency and the Institute of Health and Welfare. All known patients will receive a written report of the incident.
If you suspect that you are sick after eating in a restaurant or buying from a store, fill out the electronic food poisoning form. If a customer reports food poisoning to a food industry operator, the operator has a legal obligation to notify the local food control authority immediately. Make a report at https://ilppa.fi.
Source: The Nordic Page