Passive metaviromic surveillance using a honey-baited FTA card trap reveals vertebrate-associated and zoonotic viral signals in mosquitoes from northeastern Brazil

<title>Abstract</title> <p> Passive surveillance of mosquito-associated viromes offers a promising strategy for detecting zoonotic spillover events and monitoring emerging pathogens before clinical cases are recognized. Flinders Technology Associates ^® (FTA) cards combined with untargeted metaviromic sequencing provide a scalable approach to capture and preserve viral nucleic acids from mosquito salivary deposits without requiring cold-chain infrastructure or prior knowledge of target pathogens. Building on previous laboratory validation, we developed the BR-ArboTrap, a passive surveillance device designed to attract host-seeking mosquitoes and collect salivary deposits on honey-baited FTA cards for downstream metaviromic analysis. Here, we present the first field evaluation of the BR-ArboTrap across four municipalities in Pernambuco State, northeastern Brazil. Traps were deployed at ten fixed sampling sites per municipality for four weeks, with FTA cards replaced every 48 hours. Following Multiple Displacement Amplification (MDA), pooled FTA card extracts were analyzed by metagenomic next-generation sequencing. Bioinformatic analyses identified 22 viral taxa from six recognized families, including single-stranded DNA, double-stranded DNA, and single-stranded RNA viruses. Viral sequences were associated with diverse vertebrate (human, bat, capybara, chicken, and dog), insect (ant, fly, and bee), and plant hosts, providing indirect molecular evidence of mosquito feeding behavior and cross-species viral interactions. The detection of bat- and capybara-associated viruses highlights the epidemiological value of this approach beyond conventional arbovirus surveillance. Although no target arboviruses were detected, the recovery of diverse viral nucleic acids demonstrates that the BR-ArboTrap functions as an effective environmental sampling platform for passive virome surveillance and supports its application as a complementary tool for zoonotic surveillance and viral discovery in tropical endemic regions. </p>