EGG-NEWS is indebted to Dr. Nati Elkin, Editor of Poultry Med for a report on the risk factors associated with Salmonella Enteritidis (SE) infection in egg producing flocks in Israel*.

Between 2018 and 2023, 25,000 samples were assayed from 6,076 flocks for the presence of Salmonella.  For all serovars, 43 percent of flocks yielded any Salmonella isolate.  The respective isolation rates for Salmonella Enteritidis (181/6,076) and Salmonella Typhimurim (127/6,076) were 3 percent and 2 percent respectively.  As a result of outbreaks of SE among consumers, over two million hens were depopulated.  This would have been unnecessary had eggs from these flocks been diverted from the shell egg stream to pasteurization.

The risk factors were: -

• Hens older than 85 weeks of age.
• Flock sizes in excess of 10,000 hens.
• Cage housing.
• Close -proximity to dairy farms.
• Higher isolation rates during fall months consistent with EU observations.

The project demonstrated that vertical transmission of SE infection from breeders was nonexistent with horizontal transmission due to defects in biosecurity, maintaining infection in the industry.

It is a matter of record that all pullets are vaccinated against SE.  There is no mandatory stamping of eggs as in the EU to establish traceability.  There are no regulations relating to washing of eggs.  The absence of a cold chain may contribute to proliferation of SE within the shell during prolonged storage. Deficiencies were identified in the education of consumers and food workers on correct handling and preparation of eggs and recipes containing eggs and egg products.

*Shachaf, B. et al. Prevalence and risk factors for Salmonella infection in layer flocks in Israel between 2018 and 2023. Poultry Science. Doi.org.10.1016/j.psj 2026.10686.