P- 32 HEPATITIS A AND E VIRUSES IN CÓRDOBA, ARGENTINA: WASTEWATER-BASED EPIDEMIOLOGY AS A SILENT SENTINEL OF THE TREND OF VIRUS CIRCULATION IN THE COMMUNITY

Abstract

Introduction and Objectives: Monitoring wastewater for traces of viruses allows effective surveillance of entire communities, including symptomatic and asymptomatic infected individuals, providing information on whether a specific pathogen is circulating in a population. Such is the case of hepatitis A and E viruses (HAV, HEV). This study aimed to detect HAV and HEV in wastewater samples from Córdoba, Argentina, to provide insights into their circulation dynamics. Materials and Methods: Sewage samples were monthly and weekly collected from 2017 to 2020 and from 2020 to 2021, respectively, from 4 wastewater treatment plants located in different regions of Córdoba. Furthermore, sewage collectors of 7 neighborhoods in Córdoba city were weekly sampled during 2021. A standardized methodology was carried out for virus concentration using PEG6000 and NaCl. After automated nucleic acid extraction, HAV and HEV molecular detection were performed by TaqMan® Fast Applied Biosystems single-step multiplex RT-qPCR and specific RT-Nested PCR. Positive samples were sequenced. Results: From a total of 575 samples analyzed, 16 were RNA-HAV+ (2.80%) and 17 RNA-HEV+ (2.96%). Eight and two sequences were obtained, respectively. The HAV+ specimens were genotype IA. The majority of them belonged to 2017-2018 and were genetically close to those reported in the clinical specimens from the same period when the HAV outbreak in men who have sex with men occurred in Córdoba. The HEV+ samples belonged to genotype 3, and HEV higher occurrence was in 2021, mainly in 2 neighborhoods from Córdoba city. Conclusions: The results show HAV and HEV circulation in Córdoba, despite the low number of clinical cases reported, suggesting a continuous silent circulation of these viruses in the general population. Environmental surveillance of wastewater, together with clinical monitoring, are key tools to track the viral circulation trends over time in the population and to identify hotspots of virus excretion.