On June 4, 2002, the Aurillac Hospital Center (CH) reported to the Cantal Departmental Directorate of Health and Social Affairs (DDASS) an unusual number of six cases of Salmonella Typhimurium (S. Typhimurium) salmonellosis, with patients having been hospitalized since April 27, 2002. On the same day, the DDASS notified the Rhône-Alpes Auvergne Interregional Epidemiology Unit (CIRE). It was decided to launch epidemiological, microbiological, and veterinary investigations. A case was defined as a person residing in the Cantal department who, during an episode of acute gastroenteritis occurring on or after April 27, 2002, tested positive for Salmonella serotype Typhimurium, as isolated from a stool culture or blood culture. Strains of human origin were sent to the National Reference Center (NRC) for Salmonella and Shigella for lysotyping and pulsed-field gel electrophoresis (PFGE) profiling. An exploratory investigation was first conducted to identify the foods consumed and where they were purchased, followed by a matched case-control study to test the hypotheses generated by the exploratory investigation. Based on the places of purchase cited by the cases, the Cantal Departmental Directorate of Veterinary Services (DDSV) traced the production and distribution chains of the foods most frequently consumed by the cases. It also investigated the origin of foodborne S. Typhimurium strains received by the French Food Safety Agency (AFSSA) since early 2002 from Cantal and neighboring departments. The foodborne strains were characterized by PFGE by the AFSSA and the CNR. A total of 36 cases of S. Typhimurium salmonellosis were reported in Cantal between April 27 and July 23, 2002, of which 12 were hospitalized. Strain typing by the CNR identified a cluster of 15 cases with the DT104 lysotype and P1 profile. The same profile was found in the majority of foodborne ST DT104 strains received by AFSSA, which originated from cheese and charcuterie producers. The results of the epidemiological, veterinary, and microbiological investigations suggest that consumption of dry sausage or dry salami produced by a manufacturer located in the Cantal department is the source of the P1 profile cluster. A recall of the contaminated batch was carried out on June 27 and 28, and the local population was advised not to consume the implicated batch purchased previously. Despite the concurrent presence of sporadic and epidemic cases of salmonellosis, typing of human strains identified a cluster of grouped cases. Cross-referencing epidemiological, biological, and veterinary data led to the suspicion of a common source for these cases, underscoring its significance. (R.A.)