YONKERS, N.Y. — Two-thirds of the fresh, whole broilers tested by a third-party laboratory hired by Consumer Reports magazine were positive for Salmonella, Campylobacter or both. The study, which is currently available on-line at www.consumerreports.org, and to be published in the magazine in January 2010, is an annual project the magazine has undertaken since 1998.

The recent tests showed a modest improvement since January 2007, when the magazine found the pathogens in 8 of 10 broilers, but the numbers were still far too high, according to Consumer Reports. The study also found most disease-causing bacteria sampled from the contaminated chicken were resistant to at least one antibiotic.

"Consumers still need to be very careful in handling chicken, which is routinely contaminated with disease-causing bacteria," said Urvashi Rangan, director of technical policy at Consumers Union, the publisher of Consumer Reports. "Our tests show that Campylobacter is widespread in chicken, even in brands that control for Salmonella."

Citing a U.S. Department of Agriculture report published several weeks ago, the National Chicken Council, Washington, asserted, "Chicken is safe. Like all fresh foods, raw chicken may have some microorganisms present, but these are destroyed by the heat of normal cooking.

"A much more comprehensive survey by the U.S. Department of Agriculture found Salmonella and Campylobacter on fewer raw chickens than Consumer Reports. More important is the fact that U.S.D.A. found that the levels of microorganisms present are usually very low. Consumer Reports failed to perform this analysis. The U.S.D.A. survey also showed that poultry processing greatly improves the microbiological profile of raw chickens."

Only 5% of the raw chickens in the survey had Salmonella after chilling, and only 11% had Campylobacter, the U.S.D.A. survey showed, down from 41% and 71%, respectively, before evisceration. The U.S.D.A. survey assessed test results for the years 2007 and 2008 and was published by the Office of Public Health Science within the Food Safety and Inspection Service, an agency within the U.S.D.A.

For its latest analysis, Consumer Reports had an outside lab test 382 chickens bought last spring from more than 100 supermarkets, gourmet- and natural-food stores, and mass merchandisers in 22 states.