title: Descriptive study of California egg layer premises and analysis of risk factors for Salmonella enterica serotype enteritidis as characterized by manure drag swabs.
abstract: This cross-sectional, double-blind study reports the prevalence of Salmonella enterica serotype enteritidis (SE) on California egg layer premises using single vs. pooled manure drag swabs and presents a description of egg production and management systems in the state and an initial analysis of risk factors for SE. The study included 91% of all known eligible egg premises in California, representing the majority of eggs produced in the state. The overall prevalence of SE on California egg layer premises was 10.5%, while 1.1% of all rows sampled were positive for SE. The percentage of positive rows for SE on any premises never exceeded 25% of the 16 swabs collected per premises. A description of egg production and management on California egg layer premises is presented. Statistically significant associations for SE were not evident and were limited because of sample size and the low prevalence of SE on California egg layer premises. Several biological and management factors, such as flock health, stage of production, manure management, ventilation, and watering systems, show trend associations with premises positive for SE and require further investigation. Manure drag swabs serve as a useful tool to validate the core components of an egg quality assurance program for SE based on process control principles.
authors.affiliation: California Department of Food and Agriculture, Animal Health and Food Safety Services, 1220 N Street, Sacramento, CA 95814, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Castellan
authors.forename: Hailu
authors.initials: H
authors.lastname: Kinde
authors.forename: Philip H
authors.initials: PH
authors.lastname: Kass
authors.forename: Gregg
authors.initials: G
authors.lastname: Cutler
authors.forename: Richard E
authors.initials: RE
authors.lastname: Breitmeyer
authors.forename: Donald D
authors.initials: DD
authors.lastname: Bell
authors.forename: Ralph A
authors.initials: RA
authors.lastname: Ernst
authors.forename: David C
authors.initials: DC
authors.lastname: Kerr
authors.forename: Herbert E
authors.initials: HE
authors.lastname: Little
authors.forename: David
authors.initials: D
authors.lastname: Willoughby
authors.forename: Hans P
authors.initials: HP
authors.lastname: Riemann
authors.forename: Alex
authors.initials: A
authors.lastname: Ardans
authors.forename: Jill A
authors.initials: JA
authors.lastname: Snowdon
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Kuney
mesh_terms: D000822:Animal Husbandry / Q000592:standards*; D000818:Animals; D002140:California; D002645:Chickens; D003430:Cross-Sectional Studies; D004311:Double-Blind Method; D004531:Eggs; D004783:Environmental Microbiology; D005243:Feces / Q000382:microbiology*; D006799:Housing, Animal; D011446:Prospective Studies; D012307:Risk Factors; D012477:Salmonella enteritidis / Q000302:isolation & purification*