[Recent data on the epidemiology of dengue fever]

Because of its haemorrhagic forms often with shock syndrome, dengue fever is presently one of the most important pediatric health problems, particularly in South-east Asia. The natural reservoir of dengue is now constituted by urban human populations; travellers are the only dissemination factor of the viruses from one country to another, and all vectors are domestic species of the genus Aedes; in these mosquitoes, a vertical transmission can take place. The persistence mechanisms of dengue fever are closely related to demographic explosion, uncontrolled growth of towns and deterioration of urban environment which comes of it. The spreading mechanisms of outbreaks are related to dramatic increase of travels and the variable susceptibility of the natural Aedes populations to the viruses. All these factors appear to be directly connected with human activities; they were submitted to considerable changes since World War II and the epidemiology of the disease has been widely modified; the incidence of the disease is continuously growing year after year, building up a very worrying situation, more especially as we have no etiologic treatment nor vaccine against it.