Key points

Gastroenteritis

• The gastroenteritis outbreak that began in Week 34 is still ongoing, but the trend is downward;

• After a decline observed in Week 40 and Week 41, the number of samples testing positive for at least one enteric pathogen is rising again in Week 42, with a positivity rate of 76% in Week 42;

• Rotavirus, enteropathogenic Escherichia coli, and enteropathogenic Escherichia coli (DAEC), identified in the majority of biological samples, are the pathogens currently circulating and constitute the leading cause of acute gastroenteritis (AGE) in children under 5 years of age;

• In the third quarter of 2023, the number of boxes of anti-diarrheal medications sold to pharmacies by wholesalers increased by approximately 30% compared to the third quarter of 2022;

• After a two-week increase observed in weeks 40 and 41, the number of emergency department visits for AGE is decreasing in week 42; however, the activity rate remains significantly higher than that observed during the same period in the previous three years;

• Since the start of the GEA outbreak in Week 37, 20 severe cases have been admitted to the intensive care unit at the Mayotte Hospital Center (CHM);

• While the occurrence of a GEA outbreak at this time of year is not unusual, the current water shortage in the department, coupled with a decline in adherence to basic hygiene measures due to the lack of water, has likely resulted in an outbreak that is more intense and longer-lasting than what was observed in previous years.

Bronchiolitis

• Maintaining the green alert level “No Alert” in S42.

Influenza

• Circulation of type A(H3N2) virus;

• Increase in emergency department visits for acute respiratory infections;

• Alert level raised to orange (“Pre-epidemic”) in S42.