Point Reyes Light - November 4, 2004
State issues warning against bacteria in raw seafood
By Jacob Resneck
Citing a threefold increase in upset stomachs caused by naturally occurring bacteria, California Department of Health Services last week cautioned the public not to eat raw oysters, ceviche, and sushi, along with other forms of raw fish.
"Generally over the last six to eight weeks, we have seen a dramatic increase in illnesses reported to the department," Michael Hernandez, the Health Department’s chief of seafood safety in Sacramento told The Light. "This is not intended to restrict the sale of raw oysters in any way. It is just reminding people that [illness] can occur."
Causing upset stomachs are bacteria known as Vibrio parahaemolyticus which thrives in warmer waters and can grow inside live oysters that aren’t kept below 41 degrees, Hernandez said. While last year his department received less than 15 complaints, this year there have been 49 confirmed illnesses related to the bacteria statewide, he said. Infections from the bacteria can cause diarrhea, abdominal cramps, headache, fever, and chills, though most people recover within a few days without medical treatment because the bacteria is self-limiting.
Only 4 cases in Marin & Sonoma
Hernandez said that only four confirmed cases have been reported in Marin and Sonoma counties combined. Most of the 45 cases were reported in other Bay Area counties and the Los Angeles area.
Dr. Fred Schwartz of Marin County Public Health said his agency has received few, if any, complaints about raw oysters but that the state advisory was prudent.
"It’s just another reason [why] people who decide to eat raw oysters ... need to be aware of certain risks," Schwartz said, noting that people at high-risk, such as individuals with cancer, liver disease, or immune disorders such as AIDS, should avoid eating any form of raw fish as the consequences can be dangerous.
A sign of global warming?
Owner John Finger at Marshall-based Hog Island Oyster Company said that oyster growers are aware of the risks from Vibrio parahaemolyticus but that most cases, to his knowledge, were occurring further north in Washington State.
"We’ve been monitoring this pretty closely, and in confirmed cases, it’s only been in single digits," Finger told The Light. "We’re lucky here. With all of the growers put together, we’ve not seen more than a smattering of cases all summer."
Finger noted that outbreaks in Washington State are curious because further north waters are usually colder further north. He speculated the proliferation of Vibrio parahaemolyticus may point to warming waters due to climate change. "It is an intriguing question whether this is a sign of global warming," Finger said, "because this was not an issue 10 years ago."
Hog Island Oyster Company sells 3 million oysters annually and has only heard of two cases of illness caused by the bacteria in the past summer, Finger said. He added that he finds the timing of the state’s advisory odd because the bacteria grow in warmer waters, and Tomales Bay is cooling off as winter approaches.
"We do testing for all of our products throughout the summer months, and we tell people in the summertime to keep their oysters on ice," he said. "But now it’s gotten colder. It won’t be an issue. With the end of the summer months, [the Department of Health] probably felt they just had to release something after those cases."