Following a request from the European Commission, the Panel on Biological Hazards was asked to deliver a scientific opinion on Campylobacter in broiler meat production: control options and performance objectives and/or targets at different stages of the food chain. EFSA commissioned the development of a quantitative microbiological risk assessment (QMRA) model which has been used to estimate the impact on human campylobacteriosis due to the presence of Campylobacter spp. in broiler meat. This QMRA was also used to rank/categorize selected intervention strategies in the farm to fork continuum, for which quantitative data, of sufficient quality on efficacy for Campylobacter reduction at the point of application, were available.The evaluation of microbiological criteria required the development of a specific model by the BIOHAZ Panel, using data from the EU baseline survey, as an input.
It is estimated that there are approximately nine million cases of human campylobacteriosis per year in the EU27. The disease burden of campylobacteriosis and its sequelae is 0.35 million disability-adjusted life years (DALYs) per year and total annual costs are 2.4 billion €.
Campylobacter jejuni and C. coli are considered equivalent for the purpose of risk assessment in this opinion because there is no information on variability between these two species with respect to their behaviour in the food chain, impact of interventions or virulence for humans. There are no indications that Campylobacter strains with antimicrobial resistance behave differently in the food chain than their sensitive counterparts.
As previously estimated by the BIOHAZ Panel, handling, preparation and consumption of broiler meat may account for 20% to 30% of human cases of campylobacteriosis, while 50% to 80% may be attributed to the chicken reservoir as a whole (broilers as well as laying hens). The transmission routes from chickens to humans, other than handling, preparation and consumption of broiler meat, are not well understood, and related public health benefits cannot currently be quantified.
The public health benefits of controlling Campylobacter in primary broiler production are expected to be greater than control later in the chain as the bacteria may also spread from farms to humans by other pathways than broiler meat. There is, however, very little information about these pathways and quantifying the impact of interventions at farm level was only done for broiler meat-related cases.
Strict implementation of biosecurity in primary production and of GMP/HACCP during slaughtering is expected to reduce the level of colonization of broilers with Campylobacter, and the contamination level of carcasses and meat from colonized flocks. The effects of such implementation cannot be quantified because they depend on many interrelated local factors. Nevertheless, their impact on public health risk reduction may be considerable.
Quantitative risk assessment based on data from four countries has concluded that there is a linear relationship between prevalence of Campylobacter in broiler flocks and public health risk. The risk reduction associated with interventions in primary production is expected to vary considerably between MSs. Reducing the numbers of Campylobacter in the intestines at slaughter by 3 log10-units, would reduce the public health risk by at least 90%. Reducing the numbers of Campylobacter on the carcasses by 1 log10-unit, would reduce the public health risk by between 50 and 90%. Reducing counts by more that 2 log10 units would reduce the public health risk by more than 90%. The risk reduction associated with reducing concentrations on carcasses is expected to be similar in all MSs (although the baseline level of risk differs considerably).
Vertical transmission does not appear to be an important risk factor for colonization of broiler chickens with Campylobacter. Logistic slaughter, the separate slaughter, dressing and processing of negative and positive flocks, has negligible effect on human health risk.
Based on the results of the quantitative risk assessment, the specific control options discussed in this opinion would reduce public health risk is as follows:
In primary production, based on the results of one MS, 50-90% risk reduction can be achieved by the use of fly screens in the presence of strict biosecurity measures. Based on the results of four countries, up to 50% risk reduction can be achieved by restriction of slaughter age of indoor flocks to a maximum of 28 days, and up to 25% risk reduction by discontinued thinning.
After slaughter, a 100% risk reduction can be reached by irradiation or cooking on an industrial scale, if re-contamination is prevented. More than 90% risk reduction can be obtained by freezing carcasses for 2-3 weeks. A 50-90% risk reduction can be achieved by freezing for 2-3 days, hot water carcass decontamination or chemical carcass decontamination with lactic acid, acidified sodium chlorite or trisodium phosphate.
Scheduled slaughter aims to identify colonized flocks before slaughter so that they can be subjected to decontamination treatment. In low prevalence situations, the number of batches that need treatment is strongly reduced. Risk assessment, based on data from two countries, indicated that, when testing four days before slaughter, 75% of the colonized flocks are detected.
Control options in primary production, such as restriction of slaughter age and discontinuing thinning are directly available from a technical point of view but interfere strongly with current industrial practices. Control options for reducing carcass concentration, such as freezing, hot water and chemical decontamination are also directly available. Chemical decontamination is subject to approval in the EU and no chemicals are currently approved for use.
The BIOHAZ Panel has evaluated the public health risk reduction of applying instruments that are currently available in EU legislation, i.e. targets at primary production and microbiological criteria for foodstuffs.
Assuming all countries with a between-flock prevalence (BFP) of less than 25% or 5% in 2008 maintain that status, then achieving a target of 25% or 5% BFP in all other MS is estimated to result in 50% and 90% reduction of public health risk at the EU level, respectively. The realistic time period needed to obtain reductions due to targets in primary production will differ between countries depending on the present status and possibilities for practical implementation of different interventions and is a risk management issue. It is not realistic to consider targets for flocks with outdoor access. The share of such flocks in the total production is expected to increase in future.
The public health benefits of setting microbiological criteria were evaluated using data from the 2008 EU baseline survey. These estimates are average values for the whole EU; the impact could be very different between MSs. Theoretically, a public health risk reduction > 50% or > 90% at the EU level could be achieved if all batches that are sold as fresh meat would comply with microbiological criteria with a critical limit of 1000 or 500 CFU/gram of neck and breast skin, respectively. Correspondingly, a total of 15% and 45%, of all batches tested in the EU baseline survey of 2008, would not comply with these criteria.
Microbiological criteria could theoretically be implemented immediately but the ability to comply will also differ between MSs. They stimulate improved control of Campylobacter during slaughter.
The BIOHAZ Panel recommended that effective control options should be selected and verified under conditions where the application is intended to be used by industry to reduce Campylobacter and comply with potential targets and/or MC when established. Several data gaps were identified and generation of data in several areas was recommended.