Dengue Fever and Aedes aegypti in indigenous Brazilians: seroprevalence, risk factors, knowledge and practices.

OBJECTIVE: Dengue remains an important public health problem in Brazil. We estimated the associated factors of dengue seroprevalence among native Indians of the Tremembé ethnic and their knowledge about the aspects related to the presence of mosquitoes of the genus Aedes.

METHODS: An analytical cross-sectional study and a prospective environmental study to monitor the trapping of mosquito eggs monthly were performed. The serological portion of the study involved indigenous people living in the village of Tapera in northeastern Brazil. Ovitraps were monitored for 12 months.

RESULTS: Two hundred and ninety of 350 indigenous people (82.9%) participated in the study, with an average age of 30.2 years. The seroprevalence was 22.1% and positivity increased with age, with rates of 4.2% in children under 15 years of age, 26.8% in 15 to 59-year-olds and 42.3% in those older than 59 (CI: 2.25-15.96; P < 0.001). A higher incidence of moving to the city and the presence of underlying diseases were associated with the occurrence of dengue (P < 0.001). Four serotypes were detected, with the highest prevalence of DENV-1 (77.8%), followed by DENV-2 (70.4%), DENV-3 (14.8%) and DENV-4 (11.1%). Eggs were collected in all months of the year and in the traps located in the vicinities of the domiciles (57%).

CONCLUSIONS: We present the first seroepidemiological survey of dengue conducted among indigenous populations in Brazil. This lack of studies is likely due to the great bureaucratic challenge of working with indigenous populations, which may lead to greater negligence in the health of these populations.