Epidemiological Situation

Between March 30, 2019, and May 14, 2019, seven cases of dengue fever confirmed by the laboratory at the Mayotte Hospital Center (CHM) were reported to the Health Surveillance, Alert, and Management Unit of the ARS OI. All of these cases were imported, five from Réunion and two from Tanzania.
Starting on May 20, the first cases of dengue fever with no established link to an imported case were reported in Mayotte. Since then, reports of new locally acquired dengue cases (=autochthonous cases) have continued.
As of June 28, 2019, 35 cases of dengue fever had been confirmed by the laboratory at the Mayotte Hospital Center (CHM): 23 are autochthonous cases, 7 are imported cases, and 5 have an as-yet-unidentified origin (Figure 1). Affecting both men and women (sex ratio M/F = 1.06), the median age is 24 years [12–63], with 6 cases under the age of 16. Among the 23 autochthonous cases, 3 were hospitalized, including 2 pregnant women treated in the maternity ward.
Serotyping of specimens from two imported cases—one from Tanzania and the other from Réunion—was performed by the CHM laboratory: serotype DENV1 was identified in the case imported from Tanzania, and serotype DENV2 in the case imported from Réunion.

Among the locally acquired cases, eight were typed by the CHM laboratory, which revealed a predominance of the DENV1 serotype (7/8): two of these were confirmed by the Associated National Reference Center for Arboviruses in Réunion, which identified one DENV1 serotype and one DENV2 serotype.