Illness Linked to Oysters Is on the Rise

Federal officials see little progress in curbing other food-borne illnesses.

(Photo: Chris Graythen/Getty Images)

Apr 22, 2014· 2 MIN READ
Clare Leschin-Hoar's stories on seafood and food politics have appeared in Scientific American, Eating Well and elsewhere.

Grim news for America’s oyster lovers: Vibrio infections, often linked to that beautiful plate of raw Atlantic brininess, were up a stunning 75 percent through 2013, according to the latest Food Safety Progress Report from federal authorities.

Compared with the Centers for Disease Control and Prevention’s 2006 to 2008 report, the vibrio increase was the biggest among the six pathogens tracked by the agency. Despite the sharp rise, the pathogen only accounted for 55 hospitalizations and two deaths in 2013—like many food-borne illnesses, vibrio typically causes diarrhea, which can be serious in the immune-compromised, the elderly, or children.

Overall, America’s food safety grades show that little progress has been made in the fight to keep our food safe from pathogens.

A tiny bright spot in the report shows a modest 9 percent decline in salmonella infections. But reading the numbers can get tricky; despite declining numbers, salmonella caused 2,003 hospitalizations and 27 deaths last year.

Then there’s E. coli. There was no significant change in the E. coli strains tracked, but the CDC was frank in its warning about the pathogen.

“We could be losing ground on past progress in E. coli reduction,” according to the report.

Overall in 2013, FoodNet, the collaboration between the CDC, 10 state health departments, the USDA’s Food Safety and Inspection Service, and the FDA found that more than 19,000 infections, 4,200 hospitalizations, and 80 deaths stemmed from the pathogens it tracks and that young children were often the most affected.

Those are just the reported numbers. For each pathogen, the CDC has to estimate the number of cases that go unreported. For example, for every yersinia case reported, 123 cases are not diagnosed. For every salmonella case, 29 go undiagnosed. For every vibrio case reported, 142 cases are not.

Even the CDC admits that most food-borne illnesses can be prevented. Why?

Urvashi Rangan, Ph.D., director of the Consumer Safety Group at Consumer Reports, says one reason is that the U.S. hasn’t made enough progress on standards for meat or on the use of antibiotics that can affect pathogen resistance. She points to last year’s Foster Farms outbreak as an example. The USDA’s lack of standards for chicken parts is part of the problem, Rangan said.

“We should have standards in place for all meat at this point and strengthen them over time to get a meaningful reduction in contamination,” Rangan said. “And we need to deal with the virulence and resistance of pathogens and stop teasing them with antibiotics used in agriculture.”

Dr. Robert Tauxe, deputy director of CDC’s Division of Foodborne, Waterborne and Environmental Diseases, pointed out another snag in the efforts to curb food-borne illnesses: changes in the diagnostic tests used by laboratories that allow health officials to trace food-borne outbreaks across state lines.

Laboratories are increasingly relying on less expensive, rapid nonculture tests. That means collecting stool samples from sick patients may not be needed. Such practices can be a benefit to both doctors and patients, but for health officials who track diseases, the shift in laboratory testing means they’re not always able to get the DNA fingerprint they need to trace an outbreak to its source.

Health officials have been aware of the problem for several years.

“This trend will challenge our ability to monitor trends and detect outbreaks,” said Tauxe.

Maryn McKenna, author of Superbug, has also written that not having a cultured organism also means losing the ability to detect when the food-borne illness is antibiotic-resistant. She writes:

Antibiotic resistance is an increasingly important issue for food production; the now year-long outbreak in chicken from Foster Farms, which has racked up 524 infections in 25 states, involves a Salmonella that is multi-drug resistant. No longer being able to track resistance could mean completely losing track of foodborne epidemics.