Key Points

• Since March 30, 2019, 108 cases of dengue fever have been reported to the Health Surveillance, Alert, and Management Unit (CVAGS) of the Indian Ocean Regional Health Agency (ARS). Of these cases, only 14 were linked to travel outside the department of Mayotte

• The first locally acquired cases (autochthonous cases) have been reported since May 20. To date, there have been 86 autochthonous cases investigated, 74% of which are located in the municipality of Mamoudzou

• Within the municipality of Mamoudzou, the villages of Cavani, M’Tsaperé, and Doujani are the hardest hit: they account for 67% of autochthonous cases (58/86), with more than half (30 cases) located in Mtsaperé. Eight cases (9%) are located on Petite-Terre (Dzaoudzi, Pamandzi)

• Since the onset of local transmission of the dengue virus, the positivity rate of biological samples for dengue-like syndrome has been 19%