Overall, FSA identified effective controls while concluding that no single intervention is likely to represent a “silver bullet.” Instead, a multi-hurdle approach to microbiological control and monitoring across all stages of production is required.

Campylobacter Control from Farm to Fork

Key findings from the literature reviews, relevant to different supply chain points, include:

• On the farm: Approximately 60 percent of broilers are already Campylobacter-positive by the time of slaughter. Overall, the group of factors considered to be most important was farm management and biosecurity, with hygiene barriers and staff training consistently mentioned as effective. The evidence for the relative importance of different sources of Campylobacter was mixed due to a lack of investigations into genetic linkage and directionality of spread between broiler farms and external Campylobacter sources. Transmission of Campylobacter during transport from the farm to the slaughterhouse was also identified as a risk factor. Vertical transmission and transmission via feed, water, and litter were considered unlikely to be important risk factors. There is a need for future studies on the sources of Campylobacter introduction into broiler houses.
• At slaughter: Scalding was associated with some of the highest reductions in contamination, especially hot scalding and scalding with additives. Defeathering was associated with increased contamination, underlining it as a higher-risk stage requiring interventions, and evisceration showed inconsistent effects, suggesting the need for further optimization to ensure microbial control. Washing and chilling were identified as critical control points, with their effectiveness strongly influenced by operational parameters such as temperature, duration, and the use of antimicrobial chemicals. Several effective chemical interventions were effective but not approved for use in UK poultry. Immersion chilling was found to be effective, particularly when combined with antimicrobial chemicals and extended exposure times. When storing the products, freezing was also found to be more effective than refrigeration. Crust freezing emerged as a promising alternative.
• During processing: Chemical interventions (e.g., organic acids, oxidizing agents, and plant-based extracts) generally achieved reductions of 1–2 log₁₀ colony-forming units (CFU), with some outliers such as sorghum extract reporting up to 7 log₁₀ CFU reductions. Combined treatments also demonstrated promising results. However, non-chemical interventions such as high-pressure processing (HPP) and ultrasound showed limited efficacy when used alone, but improved performance when combined with chemicals. Packaging technologies (e.g., modified atmosphere packaging and vacuum packaging) primarily extended shelf life rather than significantly reducing Campylobacter levels, while novel approaches like zinc oxide nanoparticle pads warrant further investigation. Gaps in the literature were identified, including the absence of larger-scale pilot studies and inconsistent reporting. However, based on the evidence available, no single intervention can eliminate Campylobacter risk at the processing stage; a multi-hurdle approach is essential.
• At retail and beyond: Cooking chicken above 70 °C remains the most reliable way to inactivate Campylobacter. Refrigeration and freezing offer reductions but are influenced by storage duration and initial contamination levels. Consumer handling of raw chicken poses a significant risk of Campylobacter cross-contamination, with modeling studies predicting cross-contamination as the main pathway for campylobacteriosis, rather than undercooking. Observational studies reveal a gap between reported and actual hygiene behaviors, with proper handwashing inconsistently practiced. Short-term educational interventions can improve behavior temporarily, but sustained change may require a different approach such as early food safety education and continuous reinforcement through public health messaging.

A common theme across the literature reviews was that published studies of interventions are often underpowered, variable in design, not reflective of real-world conditions, and/or do not publish raw data, therefore limiting the robustness of analysis. Improved data reporting and further, formal meta-analysis are recommended.

Food Business Operators on Campylobacter Controls

The project included a survey of FBOs to gather insights on the perceived effectiveness of current Campylobacter control measures at each stage of the supply chain.

Results showed that industry stakeholders are continuously trying to improve standards across the supply chain by trialing new protocols and technologies and through communication and collaboration.

However, the survey also revealed a disconnect between sectors. Farms often viewed interventions as ineffective and expressed frustration over limited outcomes, while downstream stakeholders emphasized the importance of farm-level controls. Slaughterhouses and retailers reported proactive measures such as audits, sourcing policies, and routine testing, with interventions like neck skin removal and temperature control seen as effective.

Several knowledge gaps were identified, including uncertainties around the effectiveness of farm-level interventions and the influence of seasonal variation and consumer behavior on campylobacteriosis.