Emergence Of Dengue Fever In America: Patterns, Processes And Prospects

Dengue fever (DF) is the most important arboviral disease of humans, infecting an estimated 50 million persons annually. Originally a zoonosis transmitted by sylvan mosquitoes to Old World primates, dengue has emerged as a cosmotropical urban pathogen now maintained in most endemic areas by human-vector contacts, especially with the domestic and anthropophilic mosquito Aedes aegypti. Epidemics with mortality from dengue hemorrhagic fever have become increasingly common in the Neotropics since the 1981 lethal outbreak in Cuba. In this contribution the status of the disease in Latin America is revised, and the characteristics of vector biology contributing to its emergence and predominance in urban areas are explored. Although the causes for the re-emergence of dengue are many, the following factors are identified as important: 1) unplanned urbanization increasing breeding habitats of the vector, in close association with high concentrations of potential human hosts; 2) cultural aspects that result in urban landscapes dominated by large numbers of abandoned water-holding containers next to high concentrations of potential human hosts; 3) socioeconomic factors, including poor sanitation, lack of reliable water high densities of dwellings and residents in small spaces, and others; and 4) increases in human movements that promote the transport of viral serotypes and genotypes to new regions and that increase the number of susceptible humans in infected areas. Dengue control programs based solely on the application of pesticides will never be effective or sustainable. Community-based source reduction programs aimed at reducing or eliminating water-holding containers occupied by the vector are currently being promoted as the most effective solution for reducing the incidence of dengue