Eighty-three percent of chicken sold in U.S. grocery stores may contain bacteria that cause food-borne illnesses, 34 percentage points higher than the rate it found three years ago, a consumer group said Monday.
Critics, however, said the study by Consumer Reports suffered from flaws that included an unreliably small number of samples. A U.S. Agriculture Department spokesman called the report "junk science."
Consumer Reports said tests on 525 chickens -- including samples from Perdue, Pilgrim's Pride and Tyson Foods -- showed most of the poultry had campylobacter or salmonella, two of the leading causes of food-borne diseases. A test conducted in 2003 showed 49% of the birds had at least one of the bacteria.
"We think it's really startling," said Jane Halloran, a policy director for Consumers Union, which publishes Consumer Reports.
Steven Cohen, a spokesman with the USDA's Food Safety and Inspection Service, said the study was riddled with flaws such as a small sample size and uncertainty over methodology.