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 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.

First report of Aedes albopictus infected by Dengue and Zika virus in a rural outbreak in Brazil

“…In this country, previous studies identified field-collected immature forms of A. albopictus infected by all DENV serotypes [6,17,19,[45][46][47], and by ZIKV [48]. Despite the variation on the vector competence of A. albopictus according to its geographic origin [49], in other countries this is the only species involved in arboviruses transmission [19,50], including endemic occurrence in rural areas [5], reinforcing the plausibility of a similar event in Brazil.…”

“…In 2019, more than 100 countries were endemic for DENV and 87 had evidence of autochthonous transmission of ZIKV [4]. Brazil is currently the nation with the highest report of DENV [5] and ZIKV infections in the world [4]. There, Aedes aegypti is the only species proven to be involved in the transmission of these viruses [5][6][7].…”

“…Brazil is currently the nation with the highest report of DENV [5] and ZIKV infections in the world [4]. There, Aedes aegypti is the only species proven to be involved in the transmission of these viruses [5][6][7]. Consequently, epidemics affect mainly Brazilian urban areas, due to the adaptation of the vector to this environment [7].…”

“…There, this mosquito is typically present in areas with dense vegetation but has colonized consistently anthropic areas [10,15]. Brazilian studies have described A. albopictus presence in urban areas with reminiscent forests [5,6,13,[16][17][18][19][20][21][22], in slums [15], in suburban areas [13,16], and in peridomicile and intradomicile location [16,23], evidencing its dispersion across sylvatic and urban settings [10,15] and its domestication [15]. The ability to use natural and artificial containers of water for breeding [9, 12, 15-18, 21, 24] supports this ecological plasticity [25].…”

Mediadores e mecanismos envolvidos no processo de sensibilização e dessensibilização a picadas do mosquito <i>Aedes aegypti</i>.

“…Do ponto de vista da saúde pública, os mosquitos hematófagos são os principais responsáveis pela transmissão de doenças infecciosas e parasitárias de importância clínica e epidemiológica para o homem, tais como malária, filariose, febre amarela, dengue, Chikungunya e Zika, dentre outras. Esses vetores estão distribuídos em todo território brasileiro e apresentam uma ampla capacidade de adaptação às mudanças climáticas e à invasão do homem ao seu habitat natural (BEZERRA et al, 2016;BOGOCH et al, 2016;CARRINGTON;CAMERON, 2014;GUBLER, 2002). Dentre as espécies de mosquitos de importância médica, Aedes aegypti é a melhor caracterizada até o momento.…”