Surveillance of Salmonella in animal production has revealed that Salmonella serotype Enteritidis (SE) is highly prevalent in poultry. In fact, 95% of SE strains isolated in animal production sectors are found in the poultry sector, unlike Salmonella serotype Typhimurium (ST). For ST, 50 to 55% of strains are isolated in the poultry sector and 40% in the cattle sector. Specific control measures against SE and ST in poultry farms were introduced in October 1998, in the form of six interministerial decrees enacted on October 26, 1998. They require periodic testing for SE in breeding flocks, future laying pullets, and laying hens. In the event of a positive test result, the law mandates the culling of the entire flock, the destruction of eggs, and the disinfection of poultry houses followed by a fallow period. The same measures apply to ST, except in laying hen flocks. The implementation of these measures in poultry flocks coincided with a 33% decrease in the number of salmonellosis cases observed between 1997 and 2001. An ecological study with an etiological focus, based on time-series analysis, was conducted to assess the relationship between the observed decline in the number of human salmonellosis cases and the control measures implemented on poultry farms, through time-series analysis and the development of intervention models. (Excerpt from the introduction)