Bioecologia de mosquitos (Diptera: Culicidae) e infecções verticais de arbovírus, em uma agrovila na Amazônia brasileira

Abstract

Mosquitoes play an important role in the emergence and reemergence of arboviral diseases. Anthropogenic impacts modify the dynamics of composition of the mosquito fauna and apparently have favored vector species. This fact further aggravates the epidemiological scenario, especially in neotropical regions. This study aimed to evaluate: bioecological aspects of mosquitoes and interactions with aquatic/semi-aquatic macrofauna, in landscapes with different levels of anthropization; and the occurrence of arboviruses via vertical transmission, in the rural settlement Rio Pardo, Amazonas, Brazil. Eight collections were carried out over 2020-2021. Plastic containers, bamboo internodes, and tires were used to capture mosquitoes in three distinct environments: forest, forest edge, and peridomicile. These environments were in two landscapes, delimited by a 200- meter buffer: landscape with high human population density (>15 residents) and high deforestation (>43%); landscape with low human population density (≤ 15 residents) and low deforestation (≤43% deforestation). After collections, the macrofauna was removed and identified, and the mosquitoes were reared in the laboratory until the emergence of the adult. Adult vectors and/or with records of natural infection were identified, grouped into pools of up to 21 individuals and processed for viral detection by RT-qPCR. Overall, 15,547 individuals and 26 species were collected. The macrofauna was represented by 10,466 individuals and 18 non-mosquito taxa. The influence of the environment on the diversity of mosquitoes was discussed in Chapter I and the results were: forest with greater abundance and forest edge with greater species richness; the abundance and richness of mosquitoes was influenced by environments; there was a difference in composition between the forest, forest edge and peridomicile environments, whose explanation was due to the exchange of species that occurred between the environments. In Chapter II, four mosquito species were selected to evaluate their response depending on the presence of macrofauna, landscape and environment, in addition, arbovirus was investigated via vertical transmission. The following results were obtained: Aedes albopictus was positively correlated with more anthropized environments and negatively with predators; Culex (Melanoconion) was influenced by the landscape, environments and competitors; Haemagogus janthinomys was influenced only by the environment; Limatus flavisetosus was influenced by predators and competitors. Dengue-like virus was detected in a pool of Cx. (Melanoconion) and Western Equine Encephalitis-like virus was detected in a pool of Li. flavisetosus. The minimum infection rate was 0.66 in booth mosquito species detected with arbovirus. Our results reaffirm the fact that anthropic changes influence mosquito diversity and sometimes favor vector species. Competitors and predators acted to regulate the presence of the analyzed species. Furthermore, with the viral detection of arboviruses in mosquitoes of the F1 generation, we can suggest that this mechanism of vertical transmission makes these viruses last longer in nature. Finally, people living in the study settlement are vulnerable to arboviral diseases.