Salmonellosis is the main cause of food-borne human gastroenteritis in Denmark. The annual incidence of registered cases increased throughout the 1980'ies reaching a maximum of 67.2 cases per 100,000 inhabitants in 1988 (Figure 1) (1). At that time, the most prevalent serotype encountered among humans was S. Typhimurium, which also occurred frequently in the broiler production, where 80-90% of the flocks was infected. As a consequence, a voluntary Salmonella control programme was implemented in the broiler production in 1989 (2). Further, the Danish food authority carried out a campaign informing the consumers about the correct handling and preparation of poultry and poultry products. These actions led to a decrease in the annual incidence of human salmonellosis.