MOLECULAR EPIDEMIOLOGY AND SEROPREVALENCE OF CARDAMONES VARIANT WENZHOU VIRUS IN RODENTS AND HUMANS IN CAMBODIA

Abstract

Intro: Cardamones variant Wēnzhōu virus (CVWV) is a rodent-borne virus and part of Arenaviridae family. It causes occasionally fatal hemorrhagic in human, but is generally neglected among others zoonotic disease. In Cambodia, the presence of CVWV was detected in 2009 in two Rattus species. It shares more than 85% of identity in S and L segments compared to Wenzhou Mammarenavirus from China, and was shown to be pathogenic in human. To assess the molecular epidemiology of CVWV amount rodents, and the seroprevalence in human and rodents populations in Cambodia Methods: The study was conducted using rodent's serum and pool of organs, and human serum samples, collected in Phnom Penh (the Capital city of Cambodia) and two provinces (Preah Sihanouk and Kampong Cham) representing rural setting, in 2020 and 2022. The presence of CVWV RNA was tested on rodent's pool organs using RT-PCR of GPC and L genes of Arenavirus and Sanger sequencing. The detection of anti-CVWV IgG antibody was performed on rodent and human serum samples using in-house ELISA. Findings: Between 2020 and 2022, 750 pools of organs from rodents and 788 human serum samples were collected. In rodents, the overall prevalence of CVWV was 5.2% (39/750) with the highest prevalence observed in Preah Sihanouk site 3.6% (27/750). Only Rattus exulans 15.4% (32/280) and Rattus norvegicus 4.9% (7/144) species were affected by CVWV. Seroprevalence of anti-CVWV IgG was significantly highest in Rattus norvegicus (58.1%, 72/124), followed by Rattus exulans (13.3%, 24/181) (p < 0.001). In human, seroprevalence of anti-CVWV IgG was between 12.7% (100/788) to 20.3% (112/555) among two visits of 788 participants. Twenty-eight participant remained sero-positive within 2 years period. Conclusion: Our findings provide updates on prevalence and genetic characterization diversity of Mammarenavirus in Cambodia. Further investigations are needed to determine the risk behavior and impact of Arenavirus infection at human-rodent interface.