[Prediction and prevention of dengue epidemics]

Prediction and prevention of dengue epidemics are based on informations gathered about the mosquito vector species, the dengue types transmitted, the vertebrate hosts and their environment. Although Aedes aegypti is the most important vector, other Aedes may also propagate the dengue viruses. The populations of vector mosquitoes are evaluated through several indices: Breteau and/or positive house index, number of indoor resting Aedes females, etc.... The four dengue types can replicate in vertebrate hosts beside humans and in other mosquito species than Ae. aegypti. The incidence of dengue on a population is largely variable according to the immunity status, the vector competence and the virus strains. Concomitant infections by two types of dengue virus or by an another pathogen (Alphavirus) have been observed. The environmental factors influencing the dengue ecosystem are mostly climatic (temperature, rainfall, wind) but also anthropic (transportation means, public buildings). Prevention of dengue epidemics must be based on public health education in schools, community participation, epidemiological surveillance linked with good vector control teams. Nevertheless intensive research on dengue and the actions undertaken for the last forty years, dengue remains the first cause of viral morbidity worldwide.