E. coli Levels in Cattle Higher Than Thought
WASHINGTON - About half the cattle at the nation's feed lots carry the deadly E. coli bacteria during the summer, making it at least 10 times more common than previously thought, government research shows.
The study by Agriculture Department scientists does not mean that E. coli O157:H7 is any more likely to show up in the supermarket. But department officials, who outlined the findings yesterday, said they are considering new controls on cattle production and beef processing.
The research "requires us to reexamine our policies and standards for dealing with this difficult organism," Thomas Billy, administrator of the department's Food Safety and Inspection Service, said at a conference in Arlington, VA.
The bacteria, which are most commonly found in ground beef, kill about 60 people each year and sicken an estimated 73,000 more, according to the Centers for Disease Control and Prevention.
The department's findings, which will be published in April's Proceedings of the National Academy of Sciences, are based on detection methods that are far more sensitive than previously used.
The occurrence of E. coli in feed lots drops to 1 percent during the winter, but scientists found that 83 percent of the cattle they studied had been exposed to the bacteria at some point. Calves can pick up the bacteria during the birth process, while other cattle get it from manure, scientists say. Changes in feeding methods and transportation have been shown to reduce the incidence of E. coli.
Consumer groups say the government needs to require far more extensive testing of cattle and beef to prevent people from being exposed to the germs. Testing is now required only on ground beef, a program that started after tainted hamburger killed several children in Washington state in 1993.
"Like throwing darts at a dart board, although the government hits the target occasionally, it is clearly missing a lot of the problem," said Caroline Smith DeWaal of the Center for Science in the Public Interest.
The incidence of E. coli in cattle is believed to vary by region as well as time of the year. An industry-funded study released yesterday found a wide variation of infection rates at packing plants. At least 18 percent of the cattle headed for slaughter at a dozen plants were carrying the bacteria. Two of the plants had no infected cattle, and the average rate for the 12 facilities was 3.56 percent.
The bacteria were found on 0.44 percent of the fresh carcasses sampled in the study. But no E. coli showed up once the carcasses had gone through the plants' usual cleaning process, which generally involves steam, hot water, or organic acid rinses.