Two seafood companies, OM Seafood and Oregon Oyster Farms Inc., have issued recalls of oyster products harvested in Yaquina Bay, Oregon, between February 1 and 24 due to potential norovirus contamination.

The first recall, issued by Oregon Oyster Farms in late February, occurred after eight people in the Newport, OR area developed gastrointestinal symptoms consistent with norovirus. The second recall was issued Tuesday by OM Seafood, who receives its oysters from Oregon Oyster Farms. 

At this point, the source of the virus is a mystery, as norovirus-associated illnesses from oysters typically originate in warm-water environments.

“We don’t know if it came from a sewage spill or what,” a spokesman from Oregon Department of Agriculture said.

Health officials have not ruled out the possibility that the virus originated in a restaurant where Yaquina Bay oysters were handled. A spokesperson from the Oregon Public Health Division said the agencies were asked to recall all of the oysters sold this month out of “an abundance of caution.” The two companies have stopped selling and distributing oyster products as well.

The Health Department has since tested the water in Yaquina Bay and is waiting on the results as it tries to narrow down the source of the contamination. Until then, Yaquina Bay will remain closed.

Oyster meat recalled includes all half-pint, pint, half-gallon and 4 gallon buckets. Oysters in the shell include all large, medium, small, extra-small, and petite Pacific oysters, Kumamoto oysters, and Yaquina native oysters.

Yaquina Bay oysters have been distributed in five Oregon counties – Lincoln, Lane, Linn, Marion, and Multnomah – as well as to individual restaurants in New York, Boston, Texas, Mississippi, and Virginia.

Consumption of these products may cause nausea, vomiting, diarrhea, malaise, abdominal pain, headache, and fever.