CDC: E. coli illnesses on decline, but other foodborne infections increasing

By Lyndsey Layton
Washington Post Staff Writer
Thursday, April 15, 2010; 4:45 PM

Efforts to reduce illnesses caused by one of the most dangerous foodborne bacteria, E. coli O157:H7, appear to be paying off, the Centers for Disease Control and Prevention reported Thursday, but sickness caused by other pathogens is rising.

Preliminary data released by the CDC showed a 2009 drop in the incidence of infections from E. coli O157:H7, which can be lethal and is most commonly associated with ground beef but has also been detected in leafy greens and raw cookie dough. E. coli infections were the lowest since 2004, the agency said.

But there was little or no recent progress for other pathogens, according to the data. Infections from salmonella, the most common cause of foodborne illness in the United States, decreased slightly in 2009but remain above the goals set by the government. The report also detailed increases last year in illnesses from campylobacter, listeria, vibrio and cryptosporidium.

"There is more work to do," said David Goldman of the Department of Agriculture's Food Safety and Inspection Service. "In particular, salmonella remains a challenge. We have not been as successful in moving the trend line in the right direction."

Goldman credited the decrease in the E. coli infection rate to expanded testing in slaughterhouses last year and a renewed effort by USDA inspectors to flag sanitary problems.

The CDC has been collecting data since 1996 on people in 10 states with infections caused by eight bacteria and two parasites found in food.

The annual survey, published in the CDC's Morbidity and Mortality Weekly Report, documented a modest increase in the incidence of infection from listeria, which is associated with ready-to-eat meat and poultry products and unpasteurized cheeses. If contracted by a pregnant woman, listeria infection usually results in a miscarriage or stillbirth.

The report also highlighted a spike in illnesses caused by vibrio, which is often traced to raw oysters and shellfish. Illnesses from vibrio in 2009 were 85 percent higher than the annual average between 1996 and 1998. Public health officials said they were puzzled by the jump in such illnesses and suggested the problem may stem from insufficient refrigeration of shellfish after harvest.

The Food and Drug Administration wants to require pasteurization for oysters harvested from the Gulf of Mexico during warm-water months, to destroy one type of particularly virulent vibrio bacteria, but the oyster industry has fought such regulation. The issue is still under discussion, said Donald Kramer, deputy director of the agency's Office of Food Safety and Applied Nutrition.

Legislation pending in the Senate is designed to significantly beef up the FDA's authority to require food processors, farmers and fishermen to minimize the risks of contamination.

The CDC tracks foodborne outbreaks primarily through two networks, called FoodNet and PulseNet. FoodNet uses hospital records and microbial-testing programs to trace the spread of pathogens, while PulseNet uses genetic fingerprinting to link cases of illness.

In the past, outbreaks were usually identified after a number of people who had eaten in the same restaurant or fast-food chain got sick. PulseNet, which contains microbial genetic data from public health labs across the country, allows scientists to link isolated sicknesses that arise from the same product.

Children younger than 4 are particularly vulnerable to foodborne bacteria, while adults older than 50 are the most likely to be hospitalized and die from bacterial exposure, health officials said.

The CDC estimates that foodborne diseases cause approximately 76 million illnesses, 325,000 hospitalizations and 5,000 deaths in the United States each year. But Goldman acknowledged Thursday that those figures may be out of date. They were generated in 1999. The agency is working on updated data, he said.

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