EFSA evaluates factors contributing to Campylobacter in chicken

EFSA highlights a series of factors for consideration in designing national Campylobacter control measures or programmes for chickens and chicken meat. EFSA recommends that control programmes be based on an integrated approach that addresses both the chicken farms and the slaughter process. Further studies at national level could also allow better identification of risk factors for Campylobacter infections in each country.

In the report, EFSA states that batches of chickens infected with Campylobacter are 30 times more likely to produce carcasses contaminated with Campylobacter and that infected batches are also more likely to produce carcasses with higher numbers of Campylobacter on them. The report specifies however, that contaminated carcasses could also derive from non-infected batches of chickens, implying possible cross-contamination in the slaughterhouse.

The report notes that the risk of contamination of carcasses with Campylobacter varied significantly between countries and between slaughterhouses within the same country, and so did the quantity of Campylobacter found on the single carcasses. This indicates that some slaughterhouses are more capable of controlling Campylobacter than others.

Other factors were also found to be linked to an increased risk of contamination of carcasses. These are in particular the age of the slaughtered chickens; some specific periods of the year when the chickens are slaughtered - with a contamination peak between July and September; - and the time of the day when carcasses are processed; - with a higher risk of contamination later in the day.

Depopulation or “thinning” practices in chicken flocks also emerged as a factor increasing the likelihood of infection. These practices consist in selecting within a flock a certain number of chickens to be sent to slaughter, while leaving the rest to continue growing. It is believed that during these practices humans or other vectors may introduce Campylobacter and infect the remaining chickens.

Notes to editors

In the European Union, campylobacteriosis is the most frequently reported food-borne illness in humans[3]. Poultry meat appears to be a major, if not the largest, source of Campylobacter infection in humans, according to a recent opinion of EFSA’s Biological Hazards (BIOHAZ) Panel[4] . The risk for human health arises from consumption of under cooked meat or cross-contamination between foods. Safe handling of raw meat, thorough cooking and good kitchen hygiene can prevent or reduce the risk posed by contaminated chicken meat.

The report published today by EFSA’s Zoonoses Data Collection Unit focuses specifically on contamination of chickens with Campylobacter in the early stages of the food chain: that is at the beginning and at the end of the slaughter line, when the chickens arrive at the slaughterhouse and when their carcasses are chilled after slaughtering. The findings will complement the other information available on the subject, such as epidemiological studies on Campylobacter in chickens.

The findings will be utilised by risk assessors such as EFSA’s Biological Hazards (BIOHAZ) Panel and also by risk managers at Member States and EU level for the definition of possible control options.

Further Information

• Analysis of the baseline survey on the prevalence of Campylobacter in broiler batches and of Campylobacter and Salmonella on broiler carcasses, in the EU - Part B: Analysis of factors associated with Campylobacter-colonisation of broiler batches and with Campylobacter-contamination of broiler carcasses; and investigation of the culture methods diagnostic characteristics used to analyse the broiler carcass samples
• Analysis of the baseline survey on the prevalence of Campylobacter in broiler batches and of Campylobacter and Salmonella on broiler carcasses in the EU, 2008 - Part A: Campylobacter and Salmonella prevalence estimates  
   

For more information on food-borne diseases in the EU: Biological Safety of Food

[1] EFSA’s Zoonoses Unit “Baseline Survey on Campylobacter in broiler batches and on broiler carcasses” published in March 2010
[2] Including EFSA’s Biological Hazards (BIOHAZ) Panel.
[3] See EFSA’s annual  “Community Summary Report on trends and sources of zoonoses, zoonotic agents and food-borne outbreaks in the European Union” the latest issue covering 2008
[4] In its  “Scientific Opinion on Quantification of the risk posed by broiler meat to human campylobacteriosis in the EU” EFSA’s BIOHAZ Panel concluded that the handling, preparation and consumption of broiler meat may directly account for 20 to 30% of human cases of campylobacteriosis in the EU.