Salmonella Enteritidis in laying flocks: rising risks and the value of dipslides for routine hygiene monitoring

The rising prevalence of Salmonella Enteritidis in the Netherlands

Since mid-2023, the Netherlands has experienced a worrying surge in infections with Salmonella enterica serovar Enteritidis (SE). Before COVID-19, the annual average was around 281 laboratory-confirmed cases, but this number rose to 427 cases in 2023. In both 2024 and the first half of 2025, case counts remain significantly higher than historical averages.

Notably, this increase in human infections parallels a rise in SE-positive laying flocks. In 2023, 74 positive flocks were detected, followed by 81 in 2024, and already 50 in the first half of 2025. This is much higher than the historical mean of around 30 per year.

This trend highlights a clear connection: the more infected flocks within the poultry sector, the higher the risk of human infections through the consumption of contaminated eggs.

What does this mean for laying farms?

For egg producers, this trend translates into greater pressure on monitoring and biosecurity efforts. Although the NVWA (Netherlands Food and Consumer Product Safety Authority) tests flocks at least every 15 weeks, infections can spread in the intervals between official checks. Any delays in identifying and removing positive flocks increase the likelihood of contaminated eggs entering the food chain.

Therefore, in addition to mandatory government testing, there is every reason for laying farms to intensify their own hygiene monitoring. More frequent checks not only help detect Salmonella risks early, but also strengthen risk management, farm biosecurity, and ultimately, protection of public health.

Dipslides as a reliable tool for hygiene control

Dipslides provide a low-threshold yet highly effective way to conduct rapid microbiological hygiene checks. You can use them easily on surfaces and in water. For poultry farms, they offer clear advantages:

• Immediate insight into hygiene risks: Simply press the dipslide onto surfaces in poultry houses, feeders, or water lines. After incubation, microbial growth, if present, becomes visible.
• Preventive function: Routine testing helps identify patterns early, so intervention can happen before contamination spreads.
• Support for audits and quality assurance: While indicative, dipslides are a reliable support tool for hygiene programs and can complement official inspections (e.g. NVWA) or internal audits.

Simple and cost-effective: No expensive equipment or laboratory expertise is required.

Specially Designed: Dipslides for Salmonella detection

In addition to general-purpose hygiene monitoring dipslides, selective dipslides are available that are specifically developed to detect certain microorganisms, including Salmonella spp.. The specialized agar media on these dipslides inhibit competing microbes, making it easier to clearly identify the target organism.

For laying farms, this means you can perform targeted Salmonella checks with minimal effort, perfectly aligned with the sector’s growing need for more frequent monitoring between mandatory NVWA tests.

Conclusion: strengthen your grip on Salmonella with dipslides

The recent rise of Salmonella Enteritidis in poultry flocks and in human cases underlines that the risks are both current and urgent. For egg producers, proactive hygiene control and early detection of contamination are essential.

With dipslides for Salmonella detection, you gain access to a practical, affordable, and reliable tool to strengthen your on-farm monitoring program. In doing so, you not only safeguard your flock and product quality but also contribute to food safety and public health.

Looking for the right dipslides for your farm? Explore our full selection or contact us for tailored advice.

Source: https://www.eurosurveillance.org