Raw Oysters Linked to Deaths From Rare Bacteria

Los Angeles County public health officials are warning people with certain chronic diseases to avoid raw shellfish after two deaths this month linked to a rare bacterium.

Three other people in the county have been hospitalized with the Vibrio vulnificus infection since late June. All of the five patients were Latino men ages 44 to 56 with liver disease.

The bacterium is typically found in raw oysters from the Gulf of Mexico and affects people with diseases including cirrhosis, hepatitis, cancer, diabetes and AIDS.

Public health officials speculate that Latinos are more likely to purchase Gulf Coast oysters and therefore are more likely to be exposed to the infection. Latinos also were disproportionately affected by a 1985 listeria outbreak that killed 48 and was linked to contaminated Mexican cheese.

Two of the hospitalized patients purchased oysters from pushcarts, one of them as part of a marinade called campechana. Two others, including the man who died Aug. 2, bought oysters from restaurants, one in ceviche. Officials do not know how the fifth man, who died Tuesday, developed the infection because they found him unconscious.

The Vibrio vulnificus infection is fatal in 50% of cases after it enters the bloodstream, experts say. It causes septic shock, blistering skin lesions and gangrene that often requires the amputation of limbs.

By comparison, the common food bacterium salmonella causes death in fewer than 1% of known infections, according to the state Department of Health Services.

Vibrio vulnificus bacteria are naturally present in marine settings, and they thrive in high temperatures and when ocean water has a high level of salt. For people with healthy immune systems, infection can cause diarrhea, abdominal pain and vomiting, but not death.

For those with chronic diseases, symptoms typically begin within 24 hours of eating contaminated shellfish. Death can occur within two to three days.

“Even though it’s a rare disease, it’s a highly fatal disease,” said Dr. David Dassey, deputy chief of acute communicable disease control in the county’s public health department.

The number of infections this year is the highest since five people died within three weeks in 1996, Dassey said. Because the infection is much more likely in the summer, officials worry that this year’s tally may increase.

“It is such an evil disease,” said Linda Andrews, a food scientist with the Coastal Research and Extension Center of Mississippi State University. “It’s almost like an Ebola virus the way it affects the body. It’s horrible.”

One problem, Andrews said, is that many people don’t know that they have liver disease. As a result, she encourages people not to eat raw oysters from the Gulf Coast in the summer unless the oysters have been treated.

Raw shellfish from other regions, such as the Pacific Northwest and Northeast, generally do not trigger infection because water temperatures in those areas are lower.

State health officials say they have considered imposing a summer ban on oysters from the Gulf Coast, but they have never done so. Since 1991, the state has required all facilities selling Gulf Coast oysters to post warning labels.

The state typically records five to eight Vibrio vulnificus illnesses each year in Latino men, said James Waddell, acting chief of the food safety section of the California Department of Health Services.

Short of an outright ban, his department is encouraging oyster companies to pasteurize or freeze products, which eliminates the bacteria.

Treated products cost 50% more than untreated oysters, but some oyster companies say the cost is worthwhile.

“The industry would be well advised to step up to the plate and do whatever they can to prevent these types of occurrences from happening,” said John Tesvich, a Louisiana businessman whose companies sell both treated and untreated oysters.

“The illnesses hurt the image of the shellfish industry as a whole and the Gulf in particular.”