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Mar 4, 2026 - Foods

Salmonella und Eggs: Risk Persists Despite Preventive Measures

Salmonella continues to be one of the most significant bacterial pathogens of foodborne illnesses worldwide. Salmonella enterica serotype Enteritidis is particularly frequently detected. Eggs and egg-containing foods have been the focus of food safety for many years, as they can be an important source of infection. Despite extensive prevention programs and improved hygiene standards, the risk of contamination remains.

How do Salmonella get into eggs?
Contamination of eggs can occur in two different ways. On the one hand, a so-called transovarian infection is possible. In this case, Salmonella enters the interior of the egg during its formation in the hen. In this case, the bacteria can already be present in the yolk or egg white, even though the eggshell appears outwardly normal.

On the other hand, contamination of the eggshell can occur, for example, through contact with a contaminated environment, feces, or dust in the barn. Under unfavorable conditions – such as temperature fluctuations or prolonged storage – Salmonella can penetrate into the egg through the pores of the shell.

Growth and survival of the bacteria
Salmonella are relatively resilient and can multiply over a broad temperature range. Growth is generally possible between +7°C and +50°C, with optimal multiplication occurring at about 37°C. However, sufficient heating can reliably kill the bacteria: A core temperature of at least 72°C for two minutes is considered effective for inactivation.

Especially in foods with raw or inadequately heated eggs – such as desserts, sauces, or ice cream – there may be an increased risk if hygiene standards are not strictly adhered to.

Illness and symptoms
Even a few hundred Salmonella can cause illness in susceptible people. After an incubation period of usually 12 to 48 hours, typical symptoms appear, including:

Diarrhea
Abdominal pain
Nausea and vomiting
Fever
In most cases, a salmonellosis is self-limiting. However, for children, the elderly, and immunocompromised individuals, the infection can be more severe and associated with complications.

Importance for food businesses
For food companies, Salmonella plays a central role in hygiene management and is considered an important indicator for hygienic process control. Increased microbial counts can have various causes, including:

Microbiologically contaminated raw materials
Cross-contaminations in the production process
Inadequate cleaning and disinfection
Errors in thermal treatment
Interruptions in the cold chain
An effective HACCP system is therefore essential. Important measures include, among others:

Careful incoming goods inspections
Validated heating processes
Seamless temperature monitoring during storage and transport
Regular microbiological self-checks
Prevention measures in poultry farming
In recent years, extensive measures to combat Salmonella have been introduced at the European level. These include in particular vaccination programs for laying hens and monitoring programs throughout the food chain. These measures have helped to significantly reduce the number of Salmonella cases.

Nonetheless, a residual risk remains – particularly in the case of improper storage, inadequate heating, or hygiene deficiencies in processing.

Support from the BAV Institute
The BAV Institute and its partner laboratories support food companies in the microbiological examination of raw materials, egg products, and ready-to-eat foods. In addition, we advise companies on reviewing and optimizing hygiene concepts and implementing effective self-monitoring systems.

Through regular analysis and targeted prevention measures, risks can be identified early, and food safety can be sustainably improved.

Sources
BAV Institute – Salmonella Fact Sheet
Federal Institute for Risk Assessment (BfR): Salmonella and Foodborne Illnesses.