Long-Term Seroprevalence and Molecular Surveillance of Hepatitis E Virus in Macaca spp. at a Russian Primate Research Center.

Abstract

INTRODUCTION: Data on the circulation of hepatitis E virus (HEV) in primatology centers are limited, as are the knowledge of natural course of spontaneous HEV infection in monkeys. The aim of the study was to assess dynamic changes in HEV seroprevalence among monkeys of the Kurchatov Center of Medical Primatology over the last ten years and molecular and clinical analysis of sporadic cases of HEV infection in monkeys kept in the primate center. MATERIALS AND METHODS: Serum and fecal samples from 379 rhesus macaques and 179 cynomolgus macaques collected between 2014 and 2024 were tested to assess virological, hematological, and biochemical markers of HEV infection. RESULTS: Anti-HEV IgG antibody detection rates increased sharply from 28.2% in 2014-2016 to 68.9% in 2021-2024 in rhesus macaques and from 5.6% to 70.9% in cynomolgus macaques. Phylogenetic analysis of HEV sequences from macaques with sporadic infection showed their identity to HEV genotype 4 sequences from cynomolgus macaques imported from Vietnam in 2017. Sporadic HEV infection in macaques was accompanied by a slight increase in aspartate aminotransferase (AST) levels and, in some animals, elevated levels of malondialdehyde (MDA). CONCLUSIONS: A latent epizootic of HEV-4 infection was presumably due to the waterborne transmission of the virus that was initially introduced into the primate center with monkeys imported from Vietnam. Regular testing of quarantined animals for markers of HEV infection, as well as the elimination of a single flow-through drinking water supply system and the use of individual equipment for cleaning cages, may be effective measures to contain the spread of HEV in primate centers.