Investigação molecular e epidemiológica dos vírus da influenza aviária e avulavírus aviário sorotipo 1 em aves silvestres no estado de Mato Grosso, Brasil

Abstract

Wild waterfowl of the orders Anseriformes and Charadriiformes are natural hosts of avian influenza virus (AIV) and Newcastle disease virus (NDV). Migratory species play a significant role in the intra and intercontinental dissemination of these pathogens, contributing to viral amplification and maintenance in wild environments. Interspecies viral spillover is not uncommon; there, epidemiological monitoring aimed at detecting the circulation of these viruses in birdlife is essential particularly in sites serving as stopover and wintering areas for migratory birds. The state of Mato Grosso (MT), located in the CentralWest region of Brazil, is traversed by two important intercontinental migratory routes, with some bird concentration sites situated in periurban areas, where close contact between wild fauna, domestic animals, and humans is commonly observed. This state comprises three biomes rich in biodiversity: Amazon, Cerrado and Wetland, where 916 different species of wild birds have already been cataloged. Given the ecological characteristics of the state of MT, the objective of this research was to investigate whether there is evidence of AIV and NDV circulation in the local avifauna. In total, 1.138 samples oropharyngeal and cloacal swabs were tested for both agents using the RT-qPCR technique. Positive result for Alphainfluenzavirus was detected in sample collected from a wild bird belonging to the species Charadrius collaris, captured in Chacororé Bay, located in the municipality of Barão de Melgaço (MT). The positive sample was subjected to genomic sequencing (NGS), but it was not possible to obtain the complete genome for confirmation of the viral subtype. All other samples tested negative for both agents. Epidemiological monitoring in the region and further searches will be conducted to investigate these viruses in the Pantanal region of Mato Grosso.