SACRAMENTO, Calif. (CBSNewYork/AP) — Officials say about 100 people in California have contracted norovirus in the past week after eating raw oysters from British Columbia, Canada.

The California Department of Health issued a warning Wednesday about the possible risk of illness from consuming oysters harvested in south and central Baynes Sound.

Canada has reported more than 170 cases of gastrointestinal illness linked to consumption of raw oysters.

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The U.S. Food and Drug Administration says the oysters were also distributed to Alaska, Illinois, Massachusetts, New York, and Washington State.

Officials say the number of new illnesses is declining but the investigation is ongoing.

Four oyster farms in British Columbia’s Baynes Sound that were linked to illnesses remain closed.

Norovirus is contagious and causes inflammation of the stomach and intestines. Symptoms include vomiting, diarrhea and fever.

For more information, visit the FDA’s WEBSITE.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)