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United States Department of Agriculture

Agricultural Research Service

Research Project: Microbiological and Product Quality Consequences of Housing Laying Hens in Production Systems

Location: Egg Safety and Quality

Title: Integrated farm management to prevent Salmonella Enteritidis contamination of eggs

Authors
item Trampel, Darrell -
item Holder, Thomas -
item Gast, Richard

Submitted to: Journal of Applied Poultry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 28, 2014
Publication Date: June 1, 2014
Citation: Trampel, D.W., Holder, T.G., Gast, R.K. 2014. Integrated farm management to prevent Salmonella Enteritidis contamination of eggs. Journal of Applied Poultry Research. 23(2):353-365.

Interpretive Summary: Salmonella Enteritidis (SE) contamination of eggs can cause hospitalization or death in the elderly, infants, and individuals with impaired immune systems. Preventing SE infection of laying hens is essential for reducing SE outbreaks in humans. Intervening to control SE at multiple stages during egg production can reduce the likelihood that chickens will become infected and lay contaminated eggs. Efforts to prevent SE infection of egg-laying flocks should include implementing effective farm biosecurity measures, stocking farms only with SE-free chickens, controlling rodents and insects that can spread disease, and excluding wild birds and pets. Diligent cleaning and disinfection of chicken houses before introducing new flocks will minimize exposure to SE from the environment that could spread infection. Hens can be made more resistant to being colonized by SE by using feed or water additives which promote the growth of beneficial microbes in the intestinal tract to protect against colonization by pathogens. Laying hens should be also immunized with live and killed vaccines to stimulate the immune system to resist infection and egg contamination. Shell eggs should be refrigerated as soon as possible after laying to prevent the growth of SE in eggs to dangerous levels. Comprehensive SE control programs have been successful in reducing the occurrence of SE infections in both egg-laying flocks and humans.

Technical Abstract: Salmonella Enteritidis (SE) in contaminated eggs is a public health hazard which may cause hospitalization or death in the elderly, infants, and individuals with impaired immune systems. Prevention of SE infection of laying hens is an essential first step in reducing SE outbreaks in humans. Multiple interventions at several stages during egg production can combine to reduce numbers of infected chickens and keep egg contamination to low levels. Every effort should be made to exclude SE from egg production premises by implementing effective biosecurity measures, stocking the farm with SE-free replacement pullets, controlling rodent and insect vectors, and denying wild birds and pets access to chicken houses. Diligent cleaning and disinfection of chicken houses prior to introduction of a new flock will minimize environmental exposure and indirect horizontal transmission of multiple pathogens, including SE. Increased resistance of chickens to intestinal colonization by SE can be attained by the use of probiotics, prebiotics, and synbiotics. Laying hens should be immunized with live and killed vaccines to stimulate mucosal and systemic immunity and reduce the prevalence of SE-contaminated eggs. Shell eggs should be refrigerated as soon as possible after laying to keep SE cells at low levels in any contaminated eggs. Comprehensive SE control programs have proven to be successful in reducing the incidence of SE infections in both egg-laying flocks and humans.

Last Modified: 10/30/2014
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