Are raw oysters safe to eat? A seafood expert has answers

Two people recently died in Louisiana after eating raw Gulf oysters contaminated with the flesh-eating bacteria Vibrio vulnificus. Now that we have returned to the “r” months of autumn, a period historically considered safer to consume the mollusks on the half shell, seafood lovers are rightfully on edge about enjoying what many consider a saltwater delicacy.

Evelyn Watts, a seafood extension specialist with the LSU AgCenter and Louisiana Sea Grant, has spent the better part of her adult life working with the seafood industry on the best ways to process and work through regulations about their catches. She wants to set the record straight about the safety of eating Gulf oysters throughout the year.

According to the U.S. Centers for Disease Control and Prevention, vibrio is a type of bacteria that thrives in warm, brackish waters, especially between May and October. Watts said that while Louisiana is observing some above-average cases, it is important to remember that vibrio is a seasonal pathogen with most infection cases linked to wound exposure or ingestion.

On July 31, the Louisiana Department of Health reported four deaths and 17 hospitalizations from vibrio infections this year. The number of hospitalizations had risen to 22 as of the last week of August.

Watts emphasized safe handling and cooking of all Louisiana seafood. Thoroughly cooking oysters and other shellfish eliminates any vibrio risk, she said.

“The Louisiana seafood industry follows strict safety protocols, including cold-chain management and traceability systems, which includes the use of tags,” she said. “The tag color indicates if harvest refrigeration times have been followed.”

Watts said white-tagged oysters may be consumed raw while those with green tags must be sold for processing and cannot be purchased for raw consumption.

“Restaurants are required to post consumer advisories about raw shellfish risks, especially for those with liver disease or weakened immune systems,” she said. “Consumers may purchase oysters either as shellstock — live molluscan shellfish still in the shell — or shucked, where the meat has been removed from the shell.”

Watts explained that if consumers intend to purchase shellstock oysters for raw consumption, they must look for the white tag, which confirms the product has followed proper refrigeration protocols. This tag includes key information such as the harvester’s name, the dealer’s name and address, certification number, date of harvest and harvest location.

Conversely, pre-shucked oysters or half-shell oysters sold in tubs, bags or trays — whether refrigerated or frozen — are not intended for raw consumption unless the label explicitly states otherwise.

“While vibrio is more common in warmer months, it’s important to remember that it can be present year-round," Watts said. "The good news is that by staying informed and choosing properly cooked oysters, consumers can enjoy seafood safely in any season.”

According to LSU AgCenter and Louisiana Sea Grant economist Rex Caffey, oysters are the third-most lucrative seafood commodity in the state, behind shrimp and crab. Thus, the recent uptick in illnesses could adversely affect the state’s economy if the public isn’t properly informed on how to mitigate potential infections.

“Louisiana is the national leader in oyster production and accounts for more than 75% of Gulf oyster landings,” Caffey said. “The value of Louisiana’s oyster crop has varied in recent years, with an average of $65 million annually from 2022 to 2024.”

For additional information about oysters as it relates to handling and production, Watts suggests visiting https://louisianadirectseafood.com/oyster/.

Article originally posted here