Monday, June 24, 2024

Recent death from shellfish bacteria shows difficulty in tracing contamination in diversified market

The DEQ found that North Carolina oysters, pictured here, were not consumed by the Cary man who died from the bacteria. (Port City Daily photo/Mark Darrough)
The DEQ found that North Carolina oysters, pictured here, were not consumed by the Cary man who died from the bacteria. (Port City Daily photo/Mark Darrough)

After a man died after eating raw oysters and clams in a Wilmington restaurant, state agencies could not determine the exact source of the contamination due to a market that has diversified over the past two decades.

WILMINGTON — In mid-September, a man from the Raleigh area consumed both raw oysters and raw clams at a restaurant in Wilmington. The man became contaminated by Vibrio vulnificus — a bacteria found in coastal waters, often during warmer months — then died at the WakeMed hospital in Raleigh. 

New Hanover County Health Department staff visited the restaurant and found all equipment was in working order and that proper procedures for handling raw shellfish were being followed, according to Jim Jones, a spokesperson for the state’s Department of Health and Human Services (DHHS). 

RELATED: Bringing back North Carolina oysters after Hurricane Florence

Although he was unable to provide further medical details of the victim’s death because of health privacy laws, he said people with liver insufficiencies or compromised immune systems are more likely to contract Vibrio when eating raw or undercooked shellfish. He noted that there is no prohibition or embargo of oysters related to this case.

The N.C. Division of Marine Fisheries (DMF) worked with DHHS to determine the source of the shellfish, according to Jones, which were found to come from multiple areas outside of North Carolina waters. 

Shannon Jenkins, a section chief at DMF’s Morehead City office, said multiple dealers had delivered shellfish from multiple water sources to the restaurant in question, so it was not possible to determine the specific provider or source. Furthermore, although it was previously reported that only raw oysters were consumed by the man, because he had also consumed raw clams it was even more difficult to determine the exact source of the contaminated shellfish.

A diversifying supply chain

Jenkins said the shellfish industry has changed much in the past two decades. Specifically, it is more difficult today to trace the source of contaminated shellfish because restaurants commonly gather from a variety of dealers and sources, often in the same time period.

“It’s changed a lot with more boutique oysters and sampler platters and things like that,” Jenkins said. “You might go to a restaurant and get oysters from six different states on the same platter. You don’t know which one might have been the one that made you ill.”

Long gone are the days when most restaurants served oysters and other shellfish from one farm or from one region, he said.

Jenkins also said he didn’t know which states the Wilmington restaurant’s oysters and clams came from, and if he did, whether he could release that information. But he said all states are required to meet the minimum guidelines established by the National Shellfish Sanitation Program, a federal and state cooperative that sets procedures to minimize the risk of a bacteria that is naturally occurring and not related to pollution.

During the warm months between May to August, North Carolina requires harvesters to deliver shellfish to a certified dealer, where it must be refrigerated, within five hours from the time they’ve pulled a batch from the water, according to Jenkins.

“That’s the main preventative measure that is taken, to minimize the time that it’s out of water and in the hot sun,” Jenkins said. “Because that Vibrio bacteria can grow very fast until you get it down to 50 degrees or less. So it’s important to get it refrigerated in the minimum amount of time possible.” 

Proper refrigeration must also continue through the delivery process and at the restaurant or other retail location. There, procedures must be followed to minimize the time shellfish are outside of refrigerators. Each bag must be tagged, identifying the dealer and growing area so its origin can be traced. Additionally, DHHS rules require a consumer advisory, usually printed in the restaurant’s menu, providing notice to consumers that consuming raw or undercooked shellfish may increase your risk of contracting a foodborne illness. 

He said oysters at one location during a specific time period can now come from five to ten areas in other states or even from Canadian waters.

“So you might find the tags, but you don’t know which ones they ate unless the restaurant or the individual knew,” Jenkins said.

In this case, the DMF notified each state where the restaurant had supplied its shellfish from so they could follow their own procedures following a contamination, in order to “follow it back through the chain to make sure everything was done properly,” according to Jenkins.

Both Jones and Jenkins advised anyone with a compromised immune system or liver insufficiency to eat only fully cooked shellfish.

According to the Center for Disease Control (CDC), all strains of Vibriosis cause an estimated 80,000 illnesses and 100 deaths in the United States per year. Most people contract a mild form of the bacteria and recover within three days with no lasting effects. But Vibrio vulnificus can cause serious illness, limb amputation, and death. According to the CDC, approximately one in five people infected with Vibrio vulnificus die, sometimes within two days of becoming ill.

In comparison, the E. coli bacteria commonly found in meats causes approximately 265,000 hospitalizations and 30 deaths in the United States annually, according to the CDC.

Mark Darrough can be reached at or (970) 413-3815

Related Articles