Highlight: Dengue: Enhanced Surveillance Data

From May 1 to November 30 each year, the InVS coordinates enhanced seasonal surveillance of chikungunya and dengue in metropolitan departments colonized by the vector mosquito, Aedes albopictus, in collaboration with the relevant Regional Health Agencies (ARS). From May 1, 2013, to November 22, 2013, in the 17 departments of southern France under enhanced surveillance, 405 suspected cases of dengue or chikungunya were reported. Among these, 168 imported cases of dengue were confirmed, and 2 imported cases of chikungunya were confirmed. An isolated case of autochthonous dengue (local transmission) was diagnosed in the Bouches-du-Rhône department on October 21, 2013. The individual had not traveled to an area where dengue is circulating in the 15 days prior to the onset of symptoms. Epidemiological, virological, and entomological investigations were immediately conducted by the PACA Regional Health Agency (ARS PACA), the Regional Health Agency (CIRE), the National Reference Center for Arboviruses, and the Interdepartmental Mosquito Control Association (EID Méditerranée). Information campaigns targeting local municipalities, primary care physicians, and medical laboratories were carried out in the area where the affected person resides. Active case finding in the area and among physicians and laboratories has not identified any other cases to date. As a preventive measure, and although field investigations have shown a significant decrease in the mosquito population, vector control treatment has been applied in the field.The risk of further indigenous cases has been assessed as minimal, due to the low prevalence of the Aedes albopictus mosquito (tiger mosquito) in the area and the onset of winter. To date, investigations have not identified the precise source of this infection.