Aedes (Stegomyia) albopictus’ dynamics influenced by spatiotemporal characteristics in a Brazilian dengue-endemic risk city

Brazil reported the majority of the dengue cases in Americas during the last two decades, where the occurrence of human dengue cases is exclusively attributed to the Aedes (Stegomyia) aegypti (Linnaeus). Nowadays, other recognized Dengue virus (DENV) vector in Asian countries, Aedes (Stegomyia) albopictus (Skuse), has been detected in more than half of the 5565 Brazilian municipalities. Therefore, the aim of the present study was to investigate the presence of, and determine the Ae. albopictus' dynamics influenced by spatiotemporal characteristics in a dengue-endemic risk city of Belo Horizonte, Minas Gerais State's capital. Aedes albopictus were collected across four consecutive DENV transmission seasons from 2010 to 2014. These mosquitoes were caught in three selected districts, which had been reported in the previous ten years as having high mosquito densities and an elevated concentration of human dengue cases during epidemic seasons. All field-caught Ae. albopictus was individually processed by real-time RT-PCR, to research the DENV presence. The third season (p<0.05) and the Pampulha district (p<0.05) had the highest proportions of field-caught Ae. albopictus, respectively. The second season had the highest proportion of DENV-infected field-caught females (p<0.05), but there was no difference among the proportions of DENV-infected Ae. albopictus when comparing the collection in the three districts (p=0.98). Minimum (p=0.004) and maximum (p<0.0001) temperature were correlated with the field-caught Ae. albopictus in four different periods and districts. In the generalized linear model of Poisson, the field-caught DENV-infected Ae. albopictus (p=0.005), East district (p=0.003), minimum temperature (p<0.0001) and relative humidity (p=0.001) remained associated with the total number of human dengue cases. Our study demonstrated that the number of field-caught DENV-infected Ae. albopictus was inversed correlated with the number of human dengue cases. Our study raises the possibility that the DENV circulating in mosquitoes Ae. albopictus is happening in non-epidemic periods, showing that this species may be keeping only the presence of the virus in nature. Further long-term studies are necessary to better understand the role of Ae. albopictus in DENV transmission and or its vectorial competence in Belo Horizonte and in other endemic cities in Brazil and in the New World countries.