Human and environmental factors in the increasing incidence of dengue fever: A case study form Venezuela

Dengue and its more serious form, Dengue Haemorrhagic Fever, is an acute vector-borne disease, endemic in more than 100 countries in the tropics and sub-tropics. It is increasing as a public health problem with approximately two billion people at risk. The disease is transmitted by the mosquito Aedes aegypti which is highly domesticated. During the 1980s the mosquito recolonised areas in the Americas from where it had previously been eradicated and the incidence of dengue increased dramatically, affecting places where the disease had hitherto been unknown. It was identified as a global priority by the World Health Organization in 1993. Venezuela experienced major dengue epidemics in 1989 and 1995 and further outbreaks throughout the 1990s. In this paper the macro-economic issues as well as human behavioural characteristics in the occurrence of epidemic dengue are discussed in the Venezuelan context using the results of a survey in Caracas, and their significance is compared with climatic factors. Given that the vector's eradication is improbable in the near future and that no cure or vaccines are yet available, prevention is the only strategy for disease control. Vector control programmes are the current priority, but have had little success. It is argued that there is a need for individual and community participation in programmes but this will require more information as to the knowledge, attitudes and practices of the populations at risk, which suggests a role for social scientists.