The percentage of fresh whole chickens produced in the United Kingdom positive at the highest level of Campylobacter contamination has decreased, according to the latest set of results.

For the top nine retailers, 3.1 percent of chicken samples tested from October to December 2018 carried more than 1,000 colony forming units per gram (cfu/g) of Campylobacter. The figure for the previous results from July to September was 3.5 percent, for April to June 2018 it was 3.7 percent, while for October to December 2017, it was 3.6 percent.

Campylobacter is the most common cause of food poisoning in the U.K. with an estimated 280,000 cases annually. The infectious dose can be as low as a few hundred cells.

Latest figures show 11.4 percent of birds were positive in the 100-1,000 cfu/g category compared to 11 percent from July to September 2018, 12.5 percent from April to June and 16.7 percent from October to December 2017. The cfu/g 10-99 category had 22.3 percent of chickens positive for the pathogen compared to 26.7 percent in previous results, 23.3 percent in April to June and 22 percent from October to December 2017.

In the lowest category, cfu/g less than 10, 63.1 percent of chickens were positive compared to 58.8 percent from July to September, 60.6 percent in the April to June results and 57.7 percent from October to December 2017.

Michael Wight, director of policy at the Food Standards Agency, said results were encouraging.

“It is encouraging that Campylobacter levels in retail chicken are holding consistently low, however we will continue to work closely with retailers and smaller poultry businesses to bring levels down to as low as reasonably achievable,” he said.

Of the nine retailers, only Marks & Spencer, Morrisons and Tesco revealed how many samples were taken from October to December.

Marks & Spencer recorded 4 percent in the highest category in October; 2 percent in November; and 1 percent in December, based on samples from 335 chickens. That compared to 5 percent in July; 4 percent in August; and 5 percent in September, based on 317 samples.

Tesco data showed a 3 percent level of contamination based on 524 samples compared to 5 percent of 491 samples in the previous quarter. For Morrisons, 1.8 percent of birds had the higher levels of contamination from a sample of 113 chickens. In the previous three quarters, the supermarket had reported zero chickens as positive in the more than 1,000 cfu/g category.

Aldi reported 2.5 percent of birds in the highest category in the latest results, compared to 5 percent from July to September. Asda had 5.1 percent in this bracket which was lower than the 7.1 percent figure of previous results.

Co-op results for Q4 2018 showed 3 percent of chickens sampled had contamination at levels greater than 1,000 cfu/g compared to 2 percent in the third quarter. Lidl recorded 5 percent which was up from the previous 3 percent figure.

One percent of Sainsbury’s chicken samples were at the highest level versus two percent from July to September. Waitrose had 5 percent test positive for Campylobacter at 1,000 cfu/g or more compared to 3 percent in the previous results.

A Waitrose spokesperson said: “Our testing regime is rigorous and because we know that the prevalence of Campylobacter is reduced over a product’s shelf life, we have ensured our sampling is random and have adhered throughout the survey to the FSA testing protocol. These results demonstrate the robustness of our testing procedures and we are confident our approach to tackling Campylobacter is consistently effective.”