DETECTION OF HUMAN ADENOVIRUS IN AQUATIC MATRICES FROM A CLOSED DUMPSITE USING QUANTITATIVE PCR AND TARGETED METAGENOMIC SEQUENCING

Non-operational dumpsites represent sources of environmental contamination due to the absence of impermeabilization systems and leachate management. This short communication investigates viral genetic diversity in aquatic matrices influenced by a deactivated dumpsite in the metropolitan region of Rio de Janeiro, Brazil. Between 2021 and 2023, 64 water samples were collected from leachate accumulation lagoons and groundwater wells. Nucleic acids were extracted using a magnetic bead based method (Loccus EXTRACTA DNA and RNA Kit). Human mastadenovirus (HAdV) was quantified by real time PCR (qPCR or qRT-PCR) using the TaqMan system (ABI PRISM 7500) and employed as an indicator of human fecal contamination. For viral diversity assessment, samples were grouped into five pools according to sampling points and analyzed by targeted metagenomic sequencing using the Illumina Viral Surveillance Panel. HAdV was detected in two surface water samples from leachate lagoons, with concentrations ranging from 5.15 x 10^3 to 6.38 x 10^3 genome copies per liter. Metagenomic analysis identified viral families including Mastadenovirus, Parvoviridae, Coronaviridae, Polyomaviridae, Togaviridae and Flaviviridae, comprising human pathogenic viruses such as HAdV. The detection and quantification of the Mastadenovirus genus, together with the 100 percent genome coverage obtained using the Illumina viral panel, confirms its suitability as an indicator of human fecal contamination. The detection of human pathogenic viruses highlights the importance of proper landfill closure and indicates potential contamination of aquatic matrices by leachate, increasing environmental and public health risks.