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

Abstract

Brazil reported the majority of the dengue cases in Americas during the last two decades, where theoccurrence 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 thepresent study was to investigate the presence of, and determine the Ae. albopictus’ dynamics influencedby spatiotemporal characteristics in a dengue-endemic risk city of Belo Horizonte, Minas Gerais State’scapital. Aedes albopictus were collected across four consecutive DENV transmission seasons from 2010 to2014. These mosquitoes were caught in three selected districts, which had been reported in the previousten years as having high mosquito densities and an elevated concentration of human dengue cases dur-ing epidemic seasons. All field-caught Ae. albopictus was individually processed by real-time RT-PCR, toresearch the DENV presence. The third season (p < 0.05) and the Pampulha district (p < 0.05) had the high-est proportions of field-caught Ae. albopictus, respectively. The second season had the highest proportionof DENV-infected field-caught females (p < 0.05), but there was no difference among the proportions ofDENV-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. albopic-tus in four different periods and districts. In the generalized linear model of Poisson, the field-caughtDENV-infected Ae. albopictus (p = 0.005), East district (p = 0.003), minimum temperature (p < 0.0001) andrelative humidity (p = 0.001) remained associated with the total number of human dengue cases. Ourstudy demonstrated that the number of field-caught DENV-infected Ae. albopictus was inversed corre-lated with the number of human dengue cases. Our study raises the possibility that the DENV circulating inmosquitoes Ae. albopictus is happening in non-epidemic periods, showing that this species may be keep-ing only the presence of the virus in nature. Further long-term studies are necessary to better understandthe role of Ae. albopictus in DENV transmission and or its vectorial competence in Belo Horizonte and inother endemic cities in Brazil and in the New World countries.