Federal and state officials are tracking an outbreak of norovirus from raw oysters. The oysters were distributed to 17 states, Washington D.C., and Canada.

The Food and Drug Administration reported that the oysters were harvested in Nova Scotia. The agency did not report whether the oysters were frozen at the time of distribution. Food contaminated with norovirus does not have an unusual appearance or smell.

Although the information about the outbreak was reported to the U.S. Centers for Disease Control and Prevention on June 30 by the Minnesota Department of Health, the federal agency did not immediately release information about the outbreak. The Food and Drug Administration reported on July 14 that nine people were confirmed as part of the outbreak.

The outbreak investigation is ongoing, according to a notice from the FDA.

In the notice, the FDA warns consumers and restaurants to not use Fortune brand oysters harvested from NS 10, an oyster harvest area in Nova Scotia, Canada, on June 9. The implicated oysters and were distributed by Bill and Stanley Oyster Co. of Nova Scotia. Oyster containers include the harvest area information and original shipper certification number NS 6024 SS WS on the attached product tag.

The company sent the oysters to distributors in the District of Columbia, California, Colorado, Connecticut, Delaware, Florida, Georgia, Indiana, Massachusetts, Maryland, Michigan, Minnesota, New Jersey, New York, Ohio, Pennsylvania, Texas and Wisconsin. The FDA is working to obtain additional information on distribution of the oysters. The FDA did not report wher in Canada the oysters were sold.

“Consumers, especially those who are or could become pregnant, the elderly, and persons with weakened immune systems, who have recently consumed raw oysters and suspect they have food poisoning should seek medical care immediately,” according to the FDA notice.

Symptoms of norovirus

People of all ages can get infected and sick with norovirus. The most common symptoms of norovirus are diarrhea, vomiting, nausea, and stomach pain. Other symptoms include fever, headache, and body aches.

A person usually develops symptoms 12 to 48 hours after being exposed to norovirus. Most people with norovirus illness get better within 1 to 3 days.

If you have norovirus illness, you can feel extremely ill, and vomit or have diarrhea many times a day. This can lead to dehydration, especially in young children, older adults, and people with other illnesses. 

Symptoms of dehydration include decrease in urination, dry mouth and throat, and feeling dizzy when standing up. Children who are dehydrated may cry with few or no tears and be unusually sleepy or fussy.

If you think you or someone you are caring for is severely dehydrated, call your healthcare provider.