Federal agencies have closed some areas of British Columbia to commercial shellfish harvesting, including parts of Baynes Sound, west of Denman Island, while the cases of a norovirus-like illness are being investigated.

Health officials say at least 64 people have become sick after eating raw oysters from restaurants and retail locations.

A statement from the B.C. Centre for Disease Control and the provincial health authority says the 鈥渘orovirus-like鈥� gastrointestinal illnesses have been reported since Nov. 1 in the Vancouver Coastal Health, Fraser Health and Island Health regions.

Authorities say some people went to emergency departments with symptoms of diarrhea, vomiting, or stomach pain, but there have been no hospital admissions reported.

The statement says norovirus is common during the winter months, and can cause intense symptoms, including dehydration which can be a serious problem for older adults or those who are very young.

Norovirus spreads very easily from person to person but can also be caused by consuming contaminated food or water.

The statement says food contaminated with noroviruses may look, smell and taste normal, and that to kill the virus oysters can be cooked to an internal temperature of 90 C for 90 seconds before eating.

鈥淥ysters can become contaminated with norovirus that may be present in the marine environment where they are grown and harvested,鈥� the statement says.

鈥淭he B.C. Centre for Disease Control and regional health authorities are reminding the public of risks associated with consuming raw or undercooked oysters, especially those who may be at higher risk of severe illness such as children, older adults or people who may be immunocompromised.鈥�