Steady Gains in Salmonella Control as 2024 Report Confirms Low Prevalence

Published on : 30 Sep 2025

In 2024, 33 laying hen flocks tested positive for Salmonella...

UK laying flocks remain far below EU targets, reinforcing consumer confidence in British eggs and “demonstrates continued successful control of Salmonella in the egg industry.”

The recent APHA publication (25th September 2025) on Salmonella in animals and feed in Great Britain provides a retrospective account of the situation in 2024, offering valuable insight into how the poultry sector continues to manage this enduring challenge. Sixteen years after the introduction of the National Control Programme (NCP) for Salmonella, the latest figures confirm that long-term progress has been substantial.

The NCP sets a target for a maximum of 2% of laying hen flocks testing positive for regulated Salmonella serovars annually and applies to all UK commercial flocks with 350 or more birds. In 2024, 33 laying hen flocks tested positive for Salmonella - an increase of 13.8% from the 29 flocks reported in 2023, but still more than halved compared with the baseline year of 2008, when the NCP was first implemented. Importantly, only 0.24% of flocks tested positive for regulated serovars (serovars of human health concern), a figure well below the statutory 2% ceiling, reaffirming the effectiveness of the national programme in keeping prevalence at consistently low levels.

A closer look at the data reveals how the balance of regulated serovars has shifted. S. Enteritidis, once the most pressing concern, was identified in only two flocks in 2024, down from three the year before and a dramatic reduction from the peak of 14 in 2019. This decline reflects the success of vaccination campaigns and targeted interventions. In contrast, S. Typhimurium showed an increased to seven flocks compared with just two in 2023. While still within control limits and still at low levels, this rise highlights the pathogen’s adaptability and the need for renewed focus on management strategies. Meanwhile, no cases of monophasic S. Typhimurium were recorded in 2024, offering some reassurance.

Regional variations are also noteworthy. Scotland reported no positives, while England stood at 0.26% and Wales at 0.46%. Though the numbers remain low, such differences underline the importance of locally attuned surveillance and biosecurity measures. For producers, the growth of Typhimurium is a signal that complacency is not an option; this serovar is known for its persistence in environmental reservoirs and its ability to bypass traditional controls.

The report does more than catalogue prevalence. It also points to wider concerns about antimicrobial resistance, reminding the sector that even low levels of Salmonella carry long-term risks if resistant strains become more widespread. Continued vigilance, prudent antibiotic stewardship, and the refinement of pest control and vaccination strategies will be critical to staying ahead.

Taken as a whole, the 2024 results illustrate both the success and the fragility of Salmonella control. The dramatic reduction since 2008 is a major achievement, reflecting the commitment of pullet rearers, producers, regulators and vets alike. While fluctuations in individual serovars are inevitable, the overall trend remains encouraging. For consumers, the message is clear: British eggs and poultry products remain among the safest in Europe. For the industry, the results reinforce the value of sustained investment in biosecurity and demonstrate how collective action delivers long-term gains.

Regulated serovars
In terms of the detail, 9 flocks tested positive for regulated serovars — slightly up from 7 in 2023, but well below the 2019 peak of 16. The detail is as follows:
• S. Enteritidis: 2 flocks (down from 3 in 2023; down from 14 in 2019)
• S. Typhimurium: 7 flocks (up from 2 in 2023)
• Monophasic S. Typhimurium: 0 flocks (down from 1 in 2023)

In terms of the prevalence of regulated serovars:
• GB overall: 0.24% (9 of 3,700 flocks)
• England: 0.26%
• Wales: 0.46%
• Scotland: 0.00%

All remain well below the 2% target.

Prevalence of Salmonella in laying hen flocks tested under NCP in Great Britain 2008-2024

As well as regulated strains, the report also monitored a range of non-regulated serovars, providing a fuller picture of Salmonella across the national flock.

Non-Regulated Serovars
• 14 different non-regulated serovars found in 24 flocks (down from 17 in 2023)

• Most common:
* Salmonella 61:k:1,5,(7) (6 flocks) — typically sheep-adapted
* S. Newport (4 flocks) — consistently detected annually

• New detections in 2024: S. Chester, S. Corvallis, S. Havana

Isolations in laying chickens in 2024

To complement this picture, the report also examined pullets in-rear, providing reassurance about the pipeline of birds entering the laying population.

Pullets In-Rear Flocks
• No in-rear flocks tested positive in 2024 - a continued downward trend
• Last regulated serovar detection in immature flocks was in 2018.

Overall prevalence of Salmonella in flocks
0.89% which was down from 1.13% in 2022.

GB producers and pullet rearers can be proud of their achievement and it is important to recognise the continued success in controlling Salmonella since the NCP was introduced in 2008.

The 2024 report concludes that “Overall, the prevalence of Salmonella in laying hens in Great Britain remains considerably lower than in 2004 and 2005 when the EU baseline survey was carried out” and “demonstrates continued successful control of Salmonella in the egg industry.”