The Emergence of Grade A Eggs as a Major Source of Salmonella enteritidis Infections: New Implications for the Control of Salmonellosis

Abstract

From 1976 to 1986, reported Salmonella enteritidis infections increased more than sixfold in the northeastern United States. From January 1985 to May 1987, sixty-five foodborne outbreaks of S enteritidis were reported in the Northeast that were associated with 2119 cases and 11 deaths. Twenty-seven (77%) of the 35 outbreaks with identified food vehicles were caused by Grade A shell eggs or foods that contained such eggs. National data from 1973 to 1984 showed that S enteritidis outbreaks (44%) were more frequently associated with egg-containing foods than were outbreaks of other Salmonella serotypes (15%). Reflecting the geographic distribution of human illness, cultures of bulk raw eggs from pasteurization plants in the Northeast more frequently yielded S enteritidis (10%) than did eggs from other regions of the United States (0%). The epidemic rise in S enteritidis infections due to Grade A shell eggs is unlike past problems of salmonellosis associated with cracked or soiled eggs and raises the possibility of trans-ovarian contamination of eggs with S enteritidis. New techniques may therefore be needed to control resurgent egg-associated salmonellosis in the United States.