[Dengue fever: clinical features]

Abstract

The vector for dengue fever and chikungunya, Aedes albopictus, was recently identified in Southeastern France, although the usual vector for dengue fever is Aedes aegypti, raising the possibility of cases occurring among the local population via viraemic individuals returning from endemic areas. Dengue fever is usually transmitted by Aedes aegypti. It is due to an arbovirus-flavivirus of which four different serotypes are known: Den 1 to 4. Each serotype is responsible for specific prolonged immunity but no cross-reactivity exists between serotypes. Clinically, the onset is abrupt with frontal headache, retro-orbital pain, myalgia, joint pain, prostration and, in many cases, a macular rash usually sparing the face and extremities. Haemorrhagic signs may occur, such as petechiae, purpura, epistaxis or bleeding gingivae. Two severe forms of dengue fever, particularly among children below 3 years of age, include dengue haemorrhagic fever (DHF) and DHF with shock (dengue shock syndrome). If a case is suspected in metropolitan France, the diagnosis should be systematically confirmed by positive specific IgM, RT-PCR or viral isolation. Treatment of dengue fever, whether in its uncomplicated form or with hemorrhagic manifestations or shock, remains symptomatic. There is no specific anti-viral treatment. A case should be notified to allow French health authorities to take the appropriate measures for vector control.