The California Department of Public Health has closed Tomales Bay to oyster harvesting due to a norovirus outbreak associated with the oysters.
Dr. Matt Willis, Marin County’s public health officer, said the closure was issued on Jan. 3. and on the following day the state health department issued a recall order on Tomales Bay oysters that had been sold to 34 restaurants by Hog Island Oyster Co., based in Marshall.
“There were 44 confirmed cases of norovirus between Dec. 29 and Jan. 5 across the Bay Area,” Willis said. “Only seven of those 44 cases were Marin cases.”
Willis said there is no concern in this case that the outbreak is related to food handling, cultivation or harvesting practices.
“It’s likely this represents contamination of the water itself,” he said. “The water testing showed high levels of bacterial and viral contamination, which is normal following high rainfall over a long interval.”
Willis said it is unusual for a norovirus outbreak to be linked to oysters. He said there are typically about 20 norovirus outbreaks every year in Marin County, and they usually occur in places where people congregate in close quarters such as schools or nursing homes.
There are plenty of Norovirus-related raw oyster outbreaks throughout the world weekly.
Maybe not in Marin County, Matt, but globally, yes.