OBJECTIVE: In 2024, the island of Mayotte (France) was affected by a cholera outbreak. The objective of this study was to identify clinical and laboratory criteria associated with severity (defined as hypovolemic shock and/or severe acidosis) in view of improving patient triage and therapeutic management in subsequent outbreaks. METHODS: From March 18 to July 12, 2024, we screened 215 patients with cholera (positive stool PCR). We excluded five patients who died outside hospital (no data, lethality = 2.3 %) and four patients for whom no data were available. We ultimately enrolled 206 patients. Severe forms of cholera were defined as the presence of at least one of the following three objective criteria: arterial hypotension; and/or neurological impairment (GCS < 14) (hypovolemic shock); and/or venous pH < 7.20 (severe acidosis) at first medical assessment. FINDINGS: Median patient age was 19 years (8-32 years), and 83 patients (40 %) presented with a severe form, which often consisted in fever (n = 13/83, 13 % vs. n = 6/123, 5 %, p = 0.04), vomiting (n = 71/83, 86 % vs. n = 79/123, 64 %, p