Campylobacter contamination in chickens in the United Kingdom has decreased but it remains high in smaller retailers, independent shops and butchers, according to a Food Standards Agency report.

The proportion of fresh whole chicken at retail contaminated with the highest level of Campylobacter spp. has decreased from 2014 but for birds from smaller shops no decline has been seen.

The target is to reduce the percentage of chickens produced in U.K. slaughterhouses contaminated with more than 1,000 colony forming units (cfu) per gram, to 7 percent or less at retail.

A total of 1,769 samples of whole, U.K.-produced, fresh chicken were tested between August 2017 to July 2018. During the first four months, more than 1,000 birds were sampled from all retailers. After this, the FSA tested only minor retailers with Aldi, Asda, Co-op, Lidl, Marks and Spencer’s, Morrisons, Sainsbury’s, Tesco and Waitrose publishing their own results.

Just below the target
In the first months of the survey, 1,044 chickens were sampled from all retailer groups with almost all tested from August to October 2017. Campylobacter spp. were detected in the majority, 56 percent, of chicken neck skin samples and 7 percent had more than 1,000 cfu per gram of chicken skin. The highest single count was 125,000 cfu of Campylobacter per gram of chicken skin.

There were significant differences in the rate of highly contaminated chickens ranging from 0 to 21 percent between retailers that could not be explained by differences in remaining shelf-life, chicken weight, sampling period or type of rearing.

Comparison of individual approval codes, signifying the slaughterhouse premises, also showed a notable difference in the proportion of chickens with more than 1,000 cfu per gram, ranging from 0 to 27 percent.

There was no evidence of free-range and organic being more contaminated than those reared under standard conditions, but fewer free-range and organic birds were tested.

A similar level of contamination was found in the previous survey from August to October 2016 wher 6 percent of samples had counts above 1,000 cfu per gram of chicken skin. These levels are lower compared to the second survey year from August to October 2015 wher 12 percent were above 1,000 cfu per gram of chicken skin.

In the first survey year, 4,011 samples of whole, U.K.-produced, fresh chicken from February 2014 to March 2015 were tested. Prevalence of Campylobacter spp. at the highest contamination level was 19.4 percent and this ranged between retailers from 12.9 to 29.9 percent.

In the second year, the prevalence of Campylobacter in chicken declined to 11.4 percent of samples with more than 1,000 cfu per gram of chicken skin and a range of 6.7 to 17.7 percent between retailers.

In the third year, out of 4,268 samples, Campylobacter in chicken at retail dropped to 6 percent of samples with more than 1,000 cfu per gram of chicken skin with a range from 1 to 18 percent.

Problem for smaller retailers
The reporting rate for Campylobacter spp. decreased in the U.K. from 2014 to 2016. However, in England and Wales it has increased again in 2017 and 2018. It is estimated there are more than half a million cases annually in the U.K. Eating undercooked poultry or cross contamination from raw poultry meat is an important vehicle of infection. The infectious dose can be as low as a few hundred cells.

“Retailers have achieved significant reductions in levels of Campylobacter contamination since the retail chicken survey began in 2014. The FSA will continue to engage with industry and particularly smaller retailers, butchers and independents to build on this progress,” said Rebecca Sudworth, director of policy at the Food Standards Agency.

Chickens from smaller retail shops were tested from August 2017 to July 2018 (n = 829). Campylobacter spp. were detected in 75 percent of skin samples and 15 percent had counts above 1,000 cfu per gram of chicken skin. The highest was 105,000 cfu of Campylobacter per gram of chicken skin.

Comparison of individual approval codes showed a significant difference in the proportion of chickens with more than 1,000 cfu per gram, ranging from 0 to 24 percent.

There was no major difference in the proportion of highly contaminated chickens between smaller or larger chickens nor was there any evidence that free-range and organic birds were more contaminated than those reared under standard conditions.

Campylobacter jejuni was isolated from most (78 percent) chicken skin samples when isolates were submitted for speciation (n = 1024). Campylobacter coli was identified in 16 percent of samples. Both species were found in 6 percent of samples. Campylobacter coli was more frequently isolated from birds with access to range than those reared under standard conditions.