The UK continues to maintain a strong record in controlling the prevalence of Salmonella in domestically produced eggs, thanks to a robust surveillance system, stringent biosecurity measures, and industry-wide cooperation. Despite a general increase in non-typhoidal Salmonella cases in humans in 2024, the incidence within UK egg-laying flocks remains low and well within statutory limits.
Surveillance and control measures
The UK’s National Control Programme (NCP) for Salmonella in laying hens, established under EU Regulation (EC) No. 2160/2003, mandates routine testing of flocks for regulated serovars such as Salmonella Enteritidis and Salmonella Typhimurium. The programme aims to keep the prevalence of these serovars below 2% across commercial flocks—a target consistently met and often exceeded by UK producers.
According to the Food Standards Agency (FSA) and Animal and Plant Health Agency (APHA), the prevalence of regulated Salmonella serovars in UK laying flocks was just 0.24% in 2024, a figure that reflects the effectiveness of the NCP. This is a significant achievement considering the broader context: Salmonella Enteritidis and Typhimurium remain the most common causes of human salmonellosis in the UK, accounting for over 4,800 laboratory-confirmed cases in 2024.
Regional and temporal trends
- The APHA’s 2024 report highlights that England and Wales reported low flock prevalence rates, while Scotland had no positive detections of regulated serovars.
- This regional variation underscores the importance of localized surveillance and tailored interventions.
- Seasonally, Salmonella cases in humans peak during warmer months, with September 2024 being the highest reporting month for non-typhoidal Salmonella infections.
- However, this seasonal spike does not correlate with increased prevalence in eggs, suggesting that other food sources or environmental factors may be contributing to human cases.
Industry best practices and assurance schemes
The British Lion Code of Practice, adopted by over 90% of UK egg producers, goes beyond NCP requirements. It mandates vaccination of hens against S. Enteritidis and S. Typhimurium, regular testing, traceability protocols, and independent audits. Eggs bearing the Lion mark are considered among the safest in Europe.
Similarly, the Laid in Britain scheme enforces rigorous biosecurity and traceability standards, ensuring producers maintain a flawless record of Salmonella-free eggs.
Challenges and emerging risks
Despite the success, experts caution against complacency. The British Free Range Egg Producers Association (BFREPA) has urged producers to remain vigilant. At the 2025 Elanco Layer Conference, BFREPA’s Gary Ford emphasized that “one bad headline is all it takes to shake public confidence,” reinforcing the need for continuous investment in pest control, hygiene, and vaccination.
Rodents, in particular, remain a major vector for Salmonella transmission on farms. APHA advisory visits have identified weaknesses such as poor drainage and ineffective disinfectant use as recurring issues.
Vaccination and innovation
- Vaccination remains a cornerstone of Salmonella control.
- Dual-strain live vaccines are widely used to immunize hens against both S. Enteritidis and S. Typhimurium.
- These vaccines not only reduce faecal shedding but also prevent colonization of internal organs and eggs.
- Veterinary experts stress that vaccination must be complemented by rigorous biosecurity protocols, including clean water supply, pest-proof housing, and regular environmental testing.
Consumer confidence and public health
The UK’s proactive approach has led to high levels of consumer trust. According to the UK Food Security Report 2024, over 75% of consumers trust the FSA and its food safety standards. This trust is critical, especially as eggs are a staple in British diets and often consumed raw or lightly cooked.
The FSA’s 2017 guidance, based on risk assessments, even allows vulnerable groups—such as pregnant women and the elderly—to safely consume raw or runny eggs produced under assurance schemes like the Lion Code.
Sources: Available upon request