The Swiss control programme for Salmonella enteritidis in laying hens: experiences and problems.

The Swiss control programme for Salmonella Enteritidis began at the end of 1993. All efforts are focused on the elimination of infected parent and layer flocks and on the production of S. Enteritidis-free eggs. The new Zoonosis Order and more stringent import regulations help to identify S. Enteritidis-positive parent layer and layer flocks. Other measures, such as additional voluntary monitoring of parent layer flocks, hatcheries and layer flocks, increased hygiene on poultry farms and the use of heat-treated feed, serve to prevent the spread of S. Enteritidis. An important point of concern is the elimination of S. Enteritidis from contaminated poultry farms, particularly from free-range farms. In the last two years, the number of reported infections of S. Enteritidis in humans has almost fallen to the level of 1988 (the year before the onset of S. Enteritidis infection in laying hens in Switzerland).