According to a survey by a consumer organization, most chickens sold in US stores carry salmonella and/or campylobacter, the leading bacterial causes of foodborne disease.

The survey report will appear in the January 2010 issue of Consumer Reports Magazine, and describes how an analysis of fresh, whole broilers bought at stores throughout the US showed that two-thirds contained salmonella and/or campylobacter.

Consumer Reports bought 382 chickens from over 100 supermarkets, mass merchandisers, gourmet and natural food stores in 22 states, and had them analyzed by outside labs.

Altogether they tested three top brands (Foster Farms, Perdue, and Tyson), 30 nonorganic store brands, nine organic store brands, and nine organic name brands. Five of the organic name brands were labelled as “air chilled”, a slaughterhouse process that refrigerates and mists carcasses instead of dunking them in cold chlorinated water, they told the press.

The tests revealed that:

  • 62 per cent of the chickens contained campylobacter.
  • 14 per cent of them contained salmonella.
  • And 9 per cent of the chickens contained both campylobacter and salmonella.
  • Only 34 per cent of the birds were clear of both pathogens.
  • This is double the percentage of clean birds found in the 2007 survey but considerably less than the 51 per cent found in 2003.
  • Some of the cleanest overall were the air-chilled broilers; about 40 per cent of which had one or both pathogens.
  • Of the air-chilled type, 8 Bell & Evans organic broilers were free of both pathogens, but this is too small a number from which to generalize about Bell & Evans broilers overall, said the report.
  • Store-brand organic chickens carried no salmonella, but 57 per cent of them carried campylobacter.
  • Perdue had the cleanest name-brand chickens: the tests showed 56 per cent of them were free of both pathogens.
  • This is the first time since they began testing chickens that Consumer Reports has found one major brand standing out from the others in terms of having the most pathogen-free chickens.
  • The most contaminated chickens were from Tyson and Foster Farms, 80 per cent of which tested positive for either campylobacter or salmonella or both.

Consumer Reports told the media that:

“Among all brands and types of broilers tested, 68 percent of the salmonella and 60 percent of the campylobacter organisms we analyzed showed resistance to one or more antibiotics,”

The non-profit group said in a press statement that these results show that consumers “still can’t let down their guard”, and should continue to cook chicken at a minimum temperature of 165 degress Fahrenheit (74 Celsius). It is also important not to let raw chicken juices touch any other foods.

“You would think that after years of alarms about food safety – outbreaks of illness followed by renewed efforts at cleanup – a staple like chicken would be a lot safer to eat,” they wrote.

Estimates from the US Centers for Disease Control and Prevention (CDC) suggest that every year, 3.4 million Americans are infected, 25,500 end up in hospital, and about 500 die as a result of ingesting salmonella and campylobacter from chicken and other foods.

And of those people who seek medical help, about 1 in 5 infected with salmonella and over half infected with campylobacter, have antibiotic resistant strains and have to try two or more antibiotics before they find one that works.

According to Donna Rosenbaum, executive director of the national non-profit food-safety organization Safe Tables Our Priority, the problem is probably much bigger than the CDC figures suggest, because many people who get sick don’t seek help and many who do aren’t screened for foodborne infections.

According to the US Department of Agriculture (USDA), the bacteria most commonly associated with chicken are:

  • Salmonella Enteritidis, one of about 2,000 strains of Salmonella often linked to poultry and eggs, it lives in the intestinal tracts of livestock, poultry, dogs, cats and other warm-blooded animals.
  • Campylobacter jejuni is one of the most common causes of diarrheal illness in humans. “Preventing cross-contamination and using proper cooking methods reduces infection by this bacterium,” says USDA.
  • Listeria monocytogenes, discovered as a cause of human foodborne illness in 1981, this bacterium is destroyed by cooking, but a cooked product can then become contaminated through poor personal hygiene.
  • Staphylococcus aureus is found on human hands, in nasal passages, or in throats. It can end up in hand-prepared chicken meals that are improperly refrigerated, such as chicken salad.

Sources: Consumer Reports, USDA.

Written by: Catharine Paddock, PhD