S&M Shellfish Co., a US shellfish supplier based in San Francisco, California, has issued an urgent recall for oysters harvested in the Canadian province of British Columbia following multiple confirmed illnesses due to norovirus.

The recalled oysters were harvested by Pacific Northwest Shellfish and Union Bay Seafood between Dec. 1 and Dec. 9, 2024, and sent to distributors and retailers throughout the US, according to the recall notice. Products could have a certification number of BC 740 SP and BC 6001 SP.

"This product needs to be IMMEDIATELY STOPPED from consumption, distribution of any kind," the notice reads. 

The recall notice from S&M Shellfish comes shortly after Shelton, Washington-based Rudy's Shellfish recalled its oysters and Manila clams due to a norovirus outbreak, as reported by Undercurrent News. Rudy's distributed the oysters and clams to restaurants and food retailers in Arizona, California, Florida, Massachusetts, Michigan, New York and Washington.

Norovirus is a highly contagious foodborne illness with symptoms like diarrhea, vomiting, nausea and stomach pain, reports the US Food and Drug Administration. Shellfish often become contaminated with the virus when untreated human sewage enters the marine environment. While any bivalve shellfish can be contaminated with norovirus, norovirus outbreaks are generally more often linked to oysters as they are often consumed raw.