Key Points

• The seasonal gastroenteritis epidemic began in S34-2023, slightly later than in previous years. The usual seasonal pattern for gastroenteritis epidemics in Mayotte occurs during the southern winter, from July to September;

• A sharp increase in all indicators over the past 3 weeks;

• Rotavirus, identified in biological samples as the virus currently circulating, is the leading cause of acute viral gastroenteritis in children under 5 years of age during the winter;

• Hands are the primary vector for the transmission of acute rotavirus gastroenteritis. To limit the risk of transmission, careful and frequent handwashing with soap or an alcohol-based hand sanitizer is necessary;

• To date, there has been no resurgence of waterborne diseases directly linked to the current water shortage;

• However, the water shortage in Mayotte may lead to a decline in vigilance regarding the application of basic hygiene measures, which could affect the intensity or duration of the current gastroenteritis outbreak compared to what has been observed in previous years.