Health officials are warning the public of a norovirus outbreak linked to raw oysters from Canada that were distributed to restaurants and retailers in various U.S. states, including Hawaii, where several cases have been confirmed.

The Hawaii Department of Health said as of Tuesday, there have been four suspect cases of norovirus associated with raw oysters reported in the state.

Three of the four suspect cases consumed raw oysters in Hawaii County, and one consumed raw oysters in Honolulu County, between March 8 and 22.

Cases are considered suspect when no clinical testing is conducted, but epidemiological investigations indicate the customers consumed raw oysters harvested from the implicated locations and experienced symptoms consistent with norovirus.

All of the suspected cases in Hawaii have since recovered. One case, however, required hospitalization.

DOH and the U.S. Food and Drug Administration continue to investigate a multi-state outbreak of norovirus linked to the potentially contaminated raw oysters harvested in the south and central parts of Baynes Sound, British Columbia, Canada.

The oysters were distributed to restaurants and retailers in more than a dozen states, including California, Washington and Hawaii.

The DOH Food Safety Branch is conducting investigation and traceback to determine the distributors and restaurants that may have had contaminated products.

Retailers should not serve or sell raw oysters harvested from the following locations (or landfiles) within Baynes Sound: #1407063, #1411206, #278737 in BC 14-8 and #1400036, in BC 14-15, the FDA warned. “Baynes Sound” will show on product tags as “14-8” and/or “DEEP BAY”, or “14-15.”

Symptoms of norovirus include diarrhea, vomiting, nausea and stomach pain, but can also 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 one to three days, but can feel extremely ill, vomit or have diarrhea many times a day, which can lead to dehydration, especially in young children, kupuna and people with other illnesses.

The FDA warned that food contaminated with norovirus may look, smell and taste normal. Noroviruses are also relatively resistant to heat and can survive temperatures as high as 145 degrees Fahrenheit.

Oysters can cause illness if eaten raw, the FDA said, particularly in people with compromised immune systems.

Restaurants and retailers should throw any potentially contaminated oyster products in the garbage or return them to their distributor for disposal.

The FDA also warned restaurants and retailers to be aware of the potential for cross-contamination of food processing equipment, cutting surfaces and utensils that will need to be cleaned and sanitized.

Consumers who think they might have become ill from eating possibly contaminated raw oysters should contact their health care providers.

Anyone in the state who has consumed raw oysters and experienced symptoms consistent with norovirus should contact the DOH Disease Investigation Branch through the Disease Reporting Line at 808-586-4586.