Following a report on November 8, 2003, to the Savoie Department of Social Affairs (DDASS) of three cases of gastrointestinal and cardiac symptoms that occurred in two households within the same family and resulted in the death of a 63-year-old woman, an epidemiological and veterinary investigation was conducted, as the patients had linked their symptoms to the consumption of cheese from a local producer. In the following days, four new cases were reported in two other households. These new cases were geographically distant from the first family (>50 km) and had nothing in common other than the consumption of farmhouse-style tomme cheese from the same producer. Active case finding was conducted among the known customers of this producer and at healthcare facilities in the area where the first cases were reported. In total, 11 cases were identified, 7 of whom had presented with cardiac symptoms. The others had experienced short-lived gastrointestinal symptoms such as vomiting. Among those who presented with cardiac symptoms, 4 people were hospitalized, and one of them died during an acute episode. Review of the medical records of the hospitalized patients led to a diagnosis of myocarditis. Ten individuals were adults under the age of 60. The cases occurred between October 10 and November 10, 2003. All cases had consumed very matured tommes from the same producer; eight of them noted the unusual appearance of these cheeses when cut. Symptoms appeared between 2 and 24 hours before consuming the tommes. For four of them, this was their first and only time consuming the cheese. In the various households where cases were present, no one who had not consumed the tommes became ill (10 people). Among known consumers in the 7 households where cases were identified, the attack rate was 75% (11/14). An inspection of the production facility did not reveal any toxic substances that could have contaminated the cheeses during manufacturing and aging. The temperature in the ripening area was not monitored, but since it was a natural cellar, it could have reached or exceeded 20°C during the heat wave of summer 2003, when the cheeses consumed by the ill individuals were undergoing ripening. Microbiological testing of cheese samples was positive for Staphylococcus aureus, at levels not indicative of widespread contamination. Screening for genes encoding Staphylococcus aureus toxins revealed the presence of genes encoding toxins G, I, M, N, and O. Significant quantities of this bacterium were also detected in samples from production runs in September and November 2003. A test for biogenic amines was also conducted on various samples, including two from the family of the deceased: histamine levels ranging from 184 to 934 mg/kg and tyramine levels ranging from 75 to 245 mg/kg were found. Testing for mycotoxins on two samples did not reveal any Penicillium or molds that could present particular toxicity. Epidemiological investigations suggest the existence of clustered cases of a digestive and cardiac syndrome linked to the consumption of tomme cheese from the same producer. However, despite multiple investigations (clinical, microbiological, toxicological), it was not possible to determine the etiology of this syndrome. The most plausible etiological hypotheses were poisoning by staphylococcal toxins and poisoning by biogenic amines, particularly tyramine. The resumption of cheese production was contingent upon the implementation of corrective and monitoring measures. No new cases were identified following these measures. (R.A.)