Ecological Health and Freshwater Pathogen Using eDNA Metabarcoding: A Preliminary Assessment for Environmental Surveillance Development in Malaysia

River water enters human life in various ways, with many disease outbreaks closely linked to contaminated sources. This study collected water samples from the Perak River in Malaysia, extracted environmental DNA (eDNA), and analyzed biological communities using metabarcoding and sequencing techniques to assess the local environmental health of the river. Through 16S rRNA sequencing, 4045 bacterial OTUs were identified, while 18S rRNA sequencing revealed 3422 eukaryotic OTUs, highlighting the diverse microbial and eukaryotic communities in the Perak River. The results showed certain organisms such as <i>Serratia marcescens</i> and <i>Strombidium</i> with potentially abnormal abundance, based on comparisons with other studies, suggesting possible organic and heavy metal pollution. Additionally, 35 potential pathogens, including bacteria, fungi, and parasites, were detected in the samples, all of which pose potential threats to human and animal health. While most bacterial pathogens are opportunistic, their potential risks should not be overlooked. These findings provide valuable insights into the river's ecological status and help guide targeted conservation, surveillance and pollution management strategies. Ultimately, this study highlights environmental health issues through biodiversity analysis and identifies pathogens, contributing to the protection of human and animal health and aligning with the principles of the One Health approach.