Salmonella enteritidis in eggs from commercial chicken layer flocks implicated in human outbreaks.

Eggs were cultured from four commercial chicken layer houses implicated in three human outbreaks of Salmonella enteritidis serotype enteritidis infection as part of the activities of the USDA-APHIS, VS, Salmonella enteritidis Task Force. Each house was part of a multiple in-line complex, ranging from three to seven houses. Houses were located on three separate farms, and each house contained between 50,000 and 80,000 chickens. S. enteritidis phage types 8, 13a, and 23 were isolated from samples taken from environmental and organ tissue samples, but only phage type 8 was cultured from eggs. Phage type 8 was isolated from humans in all three S. enteritidis outbreaks. Frequency estimates of contaminated eggs ranged from 0.03% to 0.90%.