Key Points

• Marked increase in the number of confirmed cases in S15

• Although the majority of cases remain concentrated in the south (54%), the proportion of cases reported in St. Louis continues to decline, and the epidemic continues to spread westward.

• The DENV-1 serotype remains the most prevalent, followed by DENV-2. DENV-3 is detected only in the east.

• The proportion of hospitalized cases is higher in 2020 than in 2019.

• Numerous cases of secondary dengue have been detected, a significant portion of which are in St. Louis

• All municipalities on the island are affected by viral circulation

• More than 30 imported cases in 2020 (returnees from Madagascar (DENV2), Mayotte (DENV1), the Comoros, and Tahiti).