Oyster-related infections up, while Salmonella plateaus, says CDC report
THURSDAY, April 15 (HealthDay News) -- U.S. officials report a continuing decline in food-related illnesses caused by several common bacteria, including the most virulent form of E. coli.
But Vibrio, a pathogen most often acquired from oysters which can cause severe illness or even death, is on the rise, while rates of Salmonella infection have remained flat in recent years.
"Overall, this year's report shows a reduction in the number of illnesses due to many of these important pathogens over the past 10 to 15 years," said Dr. Chris Braden, acting director of the Division of Foodborne, Waterborne and Environmental Diseases at the U.S. Centers for Disease Control and Prevention (CDC).
"This reflects the impact of measures to prevent foodborne illness, but additional measures are needed," he said at a Thursday press conference.
The preliminary 2009 data comes from the interagency FoodNet system, which tracks laboratory-confirmed illness from nine bacteria in 10 states. The findings are published in the April 16 issue of the CDC journal Morbidity and Mortality Weekly Report.
Infections caused by Campylobacter, Listeria, Salmonella, Shiga-toxin-producing E. coli (STEC) 0157, Shigella and Yersinia, have declined overall since 1996.
But decreases in the incidence of infections caused by Salmonella, Listeria and Campylobacter have essentially plateaued since 2004, causing some concern.
"Salmonella continues to be a challenge. It is the most commonly diagnosed foodborne illness," Braden said. "Its incidence has declined by 10 percent since 1996, but it is the furthest of any of the pathogens for the goals we have set for reduction."
Not all Salmonella infections are transmitted by food. Some occur from direct contact with baby chicks, turtles, frogs or their environment and from drinking contaminated water, Braden added.
Shigella and E.coli infections have decreased significantly since 2006.
"Infections of STEC 0157 [E. coli] , which causes one of the most severe forms of illness, showed an early decline, then plateaued," Braden said. "Then, in 2009, it decreased by 25 percent compared with the previous three years and has reached its lowest level since 2004. The decrease may be due to continuing efforts to decrease contamination of ground beef and leafy green vegetables consumed raw."
Although the incidence of Vibrio-related illness is up, the pathogen causes only a small percentage of overall foodborne illness, Braden said.
"The illnesses are typically attributed to temperature exposure of the shellfish after they're harvested so we have been trying to improve the practices in the industry in that regard," said Donald Kraemer, deputy director of the U.S. Food and Drug Administration's Office of Food Safety. "States have, within the last couple of years, implemented some controls but unfortunately we haven't seen the numbers come down so we are taking a look at why that is."
But officials emphasized that consumers can implement protective measures in their own homes.
"Consumers can always protect themselves if they follow our four safe-handling guidelines: clean, separate, cook and chill," said Dr. David Goldman, assistant administrator of the Office of Public Health Science, part of the U.S. Department of Agriculture's Food Safety and Inspection Service. "This provides some extra measure of safety."
There's more on foodborne illness at the U.S. Centers for Disease Control and Prevention.
SOURCES: April 15, 2010 press teleconference with Chris Braden, M.D., acting director, Division of Foodborne, Waterborne and Environmental Diseases, U.S. Centers for Disease Control and Prevention; David Goldman, M.D., assistant administrator, Office of Public Health Science, U.S. Department of Agriculture Food Safety and Inspection Service; Donald Kraemer, deputy director, Office of Food Safety, U.S. Food and Drug Administration; April 16, 2010, Morbidity and Mortality Weekly Report
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