Efeitos do uso da terra na biodiversidade de culicídeos e potencial emergência de arbovírus na Amazônia meridional

Abstract

The Amazon Rainforest is considered the largest reservoir of culicids and arboviruses in the world. These arboviruses are maintained in a cycle involving vertebrate hosts and hematophagous arthropods, especially those belonging to the Culicidae family. The Amazon has been under intense anthropization, especially in the so-called "Arc of Deforestation", located in the Eastern and Southern regions. The emergence and transmission of infectious diseases are increasing due to land use changes. This research had the purpose of verifying the association of land use with mosquito biodiversity, presence of arboviruses, as well as to discuss the potential risk of arbovirus emergence in the Southern Amazon. Culicids were collected in 39 forest remnants, with different degrees of disturbance, located in the North Central region of the State of Mato Grosso, Southern Amazon, during the dry seasons of 2015 and 2016. The collections were performed using CDC light traps with CO2 for 72 hours. Generalized Linear Models and Logistic Regression Models were used to associate the degree of landscape disturbance with culicids richness and abundance. Mosquito pools were screened by inoculation onto cell cultures to determine the presence of arboviruses. Immunofluorescence, viral genome detection with Multiplex-Nested-Polymerase Chain Reaction (M-N-PCR) and Sanger sequencing were also used. We collected total of 1,960 culicids, belonging to 50 species, including 20 species associated with the transmission of arboviruses, including the species Coquillettidia venezuelensis, Culex coronator complex and Ochlerotatus serratus complex, which are vectors of arboviruses circulating in Brazil and in the region, such as Saint Louis encephalitis, Yellow Fever and Mayaro. Cx. coronator complex and Oc. serratus complex were associated with highly preserved and/or highly disturbed landscapes. It is possible that these mosquitos are adapting to anthropic environments and, as a consequence, this adaptation may favor the emergence and dissemination of arboviruses. Four mosquito pools (Cx. declarator, Cx. Melanoconion section, Oc. serratus complex, and Uranotaenia lowii) were positive for the Flavivirus Ilheus (ILHV). Our results showed association of land use with the increase of arbovirus vectors richness and abundance, also, indicated the circulation of ILHV and the risk of its emergence, as well as the potential emergence of other arboviruses in the Southern Amazon.