The First Documented Detection in Taiwan of The Hepatitis E Virus in Rats

Abstract Background: Human infections by rat HEV (HEV-C1) have been serially reported, including a case who had visited Taiwan before having the illness in 2019. The objective of this study was to investigate whether HEV-C1 is circulating and causing human infections in Taiwan.Methods: Fifty acute-phase human sera samples from HEV suspected patients with the negative results were randomly chosen for retrospective review. Rat sera were collected from 3 Rattus rattus and 47 R. norvegicus, which were captured at international airports or harbors. Identifying HEV-C1 RNA was performed by hemi-nested RT-PCR in human and rat serum samples. Rat sera were also tested for anti-rat HEV antibodies. Results: HEV-C1 RNA was not detected in either human or R. rattus samples, but the viral RNA was identified in two R. norvegicus samples. The 2 rat HEV strains shared identical partial sequences in the RNA polymerases gene. In serology, anti-HEV antibodies were detected in 52% (26/50) of the trapped wild rats.Conclusions: This study documents the first detection of HEV-C1 in Taiwan. The high homology between HEV-C1 sequences from rats observed in this study might result from viral circulation and transmission within certain rodent populations. The risk of indigenous human infection in Taiwan should not be ignored because of the domestic detection of HEV-C1 RNA.