Norovirus sickens hundreds in Sweden

Officials in a Swedish region have received more than 300 reports of suspected food poisoning after eating at local restaurants.

Authorities in Lerum said the outbreak can be traced to two Gobi Sushi restaurants in Floda and Lerum. The outlets have been closed at the request of authorities since April 21.

Norovirus is the cause of symptoms, but the source of infection has not been identified.

“We will take more samples of unopened packages in the restaurants to see if we can find the source of the norovirus,” said Anna Engström, from the environmental unit in Lerum.

The environmental unit is still awaiting several conclusive results from previous sampling in the restaurants.

The investigation also involves the Swedish Food Agency (Livsmedelsverket) and Smittskydd Västra Götaland, an agency that tries to prevent and reduce the spread of infectious diseases to and between people.

Restaurant reaction
In a statement on Facebook, Gobi Sushi said it changed suppliers of fish about a month ago.

“Since then, we have mainly bought fresh salmon, tuna, white fish and crab products from a supplier that delivers from Stockholm every week. After receiving, we freeze the products and then bring out the amount needed for each working day for thawing according to our routines.”

In some samples, aerobic microorganisms and bacteria within the group Enterobacteriaceae have been identified. Results were not at a level that directly cause illness. However, findings show that routines for storage, the cold chain, handling, and hygiene should be improved.

“The exact source of the infection and which food might have been the source are not yet fully determined. What we can do, and have already done, is to take full responsibility for our own routines,” according to the statement.  

“We have reviewed our working methods with all staff and had clear briefings of how raw materials should be received, frozen, defrosted, refrigerated, marked with date and time, separated and handled with clean equipment. We have also gone through hand hygiene, cleaning, disinfection and how to keep the workplace clean and safe every day. We take the situation very seriously and do everything we can to improve, clarify and strengthen our routines so that something like this does not happen again.”

About norovirus infections
Food and beverages contaminated with norovirus may not look or smell bad, but it can cause severe illness.

Symptoms of norovirus infection may include vomiting and/or diarrhea, nausea, muscle aches, fever, and headache, according to the Centers for Disease Control and Prevention. Symptoms typically start 12 to 48 hours after exposure and can last for one to three days. Most people recover without treatment, however some may need medical attention for dehydration. People with norovirus infections can spread the infection easily to others. The virus can live on surfaces for long periods of time. 

To prevent others from getting sick always wash hands carefully with soap and warm water after using the bathroom or changing diapers. Use soap and water to clean toilets or other areas that may be soiled with stool or vomit.