In late June 2012, the municipality of Arâches-La Frasse reported the absence of about 30 students due to acute gastroenteritis, including one hospitalization.

During the exploratory survey, several assumptions were raised, including the contamination of drinking water. The latter was excluded following an environmental investigation.

The stool cultures collected revealed the presence of Salmonella, which helped direct investigations. Following the epidemiological exploration with students and their parents, the parent associations, the physician and pharmacy of the city, a collective food poisoning was identified.

It was linked to a school meal that took place on 23 June. A cohort study was conducted among participants in this meal (47 participants were sick compared to 56 who were not). This analysis, combined with the survey of veterinary services, contributed to establish a link between patients and the consumption of roasted hams. Human and food strains were subtyped using Crispol analysis by the National Reference Centre (CNR) for Salmonella and the National Salmonella Reference Laboratory, and were compared. 
They had the same profile, Salmonella Typhimurium DT104 CT30, confirming the link between the consumption of ham and cases of salmonellosis. It is likely that contamination of ham took place during handling after roasting.