Salmonella enteritidis control programs in the United States.

A sharply rising incidence of salmonellosis in humans caused by Salmonella enteritidis (SE) in the United States between 1985 and 1989 resulted in a government-sponsored outbreak traceback program which was started in 1990. Layer flocks considered the sources of egg-implicated outbreaks would be tested for SE and the eggs from these flocks would be diverted to pasteurization plants. A program to eliminate SE from primary and multiplier breeding flocks was started at the same time. A subsequent spent hen survey and a survey of prepasteurized liquid egg material revealed that SE was much more prevalent than had been suspected, and that the highest prevalence was found in the northeastern and middle Atlantic states. Since the SE rates did not decrease during the next 2 years, a pilot project was started in 1992 in Pennsylvania, in one of the most highly affected areas. The project was designed to reduce the number of SE outbreaks by diverting eggs from SE-affected flocks and at the same time attempting to delineate the epidemiology and control aspects of the disease. With the results generated during the fist 18 months of the Pilot Project, a much larger SE prevention program will start in the same area, in October 1993.