According to the current scientific knowledge, the only available means of controlling infections caused by the dengue virus is the elimination of its principal urban vector, the Aedes aegypti mosquito. Brazil has been implementing programs to fight the mosquito for decades; however, since the beginning of the 1980's the geographic range of infestation has been expanding steadily, resulting in increased circulation of the virus, large epidemics, and increased endemic transmission in different urban areas. The current epidemiological situation confirms the difficulties of preventing infection, and has led the Ministry of Health to request an evaluation of the effectiveness of the dengue control actions that have been implemented in the city of Salvador. In this article, we present the results of this evaluation. Using a prospective design, serologic inquiries were made in a sample population of residents of 30 urban "sentinel areas." The results revealed high overall seroprevalence (67.7%) and sero-incidence (70.6%) for the circulating serotypes (DEN-1 and DEN-2), with large variations among the 30 areas studied. The effectiveness of control measures appears to be low, and although a preventable fraction of 29.7% was found (even in sentinel areas with Infestation Rates < 3%), [Indices existe, mas rates é mais usado] the incidence of infections in these areas was still very high (55.4%). We believe it is necessary to revise the technical and operational strategies of the infection control program in order to attain infestation levels that are low enough to interrupt the circulation of the dengue virus.
Dengue; Epidemiology; Aedes aegypti; Control effectiveness
