Managing Campylobacter in chicken flocks and their meat is challenging, according to a study looking at surveillance methods in Europe.

Researchers compared the different programs for Campylobacter in broiler production across EU countries to identify the most promising practices to control the pathogen.

Campylobacter infections are often related to eating undercooked poultry meat or its improper handling.

Findings revealed that many countries test neck skin samples for Campylobacter as per the Process Hygiene Criterion (PHC) set in European regulation. Variations are seen in Norway and Iceland, wher weekly sampling is performed during peak infection periods only, or in Iceland, wher the limit is 500 colony forming units per gram (CFU/g) instead of 1,000 CFU/g.

The PHC limit is 1,000 CFU/g in 15 out of 50 samples. Beginning in January 2025, it will be 1,000 CFU/g in 10 out of 50 samples in all member states.

Reason for decline uncertain
The incidence of campylobacteriosis has declined in all EU countries, except France, since introduction of the PHC in 2018. However, it is unclear whether this is a real reduction or underreporting during the COVID-19 pandemic.

“It remains uncertain if the tightening of hygiene measures in slaughterhouses have had an impact on the reduction of human incidence rates,” said researchers.

Data comes from Denmark, Estonia, Finland, France, Germany, Iceland, Italy, Norway, Poland, Portugal, Serbia, and Sweden in 2020 and 2021. Efforts are being made by some countries to implement national surveillance in broilers both on farms and at slaughterhouses.

National monitoring, surveillance and control measures for Campylobacter in the broiler meat chain are not harmonized across countries, according to the study, published in the journal Food Control.

Data in neck skin tests show that less than 2 percent of samples in Estonia, Finland, Norway, and Sweden exceeded the 1,000 CFU/g limit in 2020 and 2021. Rates in Denmark and Germany were around 7 percent, they were slightly more in Italy and Portugal but were highest in France at between 27 and 28 percent. The number of samples tested varied with France reporting the most.

only Nordic countries have national action plans for Campylobacter. Norway and Iceland collect samples on farms. Denmark, Finland, and Sweden take samples at slaughterhouses. In Denmark, the national program has resulted in the reduction of Campylobacter in broiler flocks and meat, but only a small decrease in human infections.

Country differences
In all countries except Finland and Norway, at least three or four chilled neck-skin random samples from broilers belonging to the same flock are collected at the slaughterhouses. In Finland and Norway, neck skin samples are collected prior to chilling.

Iceland and Norway test flocks close to the slaughter date and when a farm tests positive, authorities implement measures such as logistic slaughter (processing infected flocks last), heat treatment or freezing the meat from these flocks. In Iceland, frozen meat is further processed before being put on the market. 

“Sampling before slaughter enables the planning of preventive measures for the upcoming slaughter of Campylobacter-positive broiler flocks, wheras sampling at slaughter provides only retrospective information,” said researchers.

In Sweden, sites slaughtering more than 100,000 broilers yearly must be sampled at least once a week between June and September. In Iceland and Finland, slaughterhouses can reduce sampling to every two weeks if the PHC has been met in the previous year. Between November and May in Finland, the sampling for Campylobacter PHC can be once per month.

“More efforts should be promoted in the future, since campylobacteriosis is still the most commonly reported zoonosis in Europe, while also addressing the interventions in animal species other than poultry, and keeping the consumers informed about the risks of foodborne diseases related to some domestic practices,” said researchers.