Epizootiological study of rodent-borne hepatitis E virus HEV-C1 in small mammals in Hanoi, Vietnam

Abstract

There is concern about the zoonotic potential of rodent-borne hepatitis E virus, designated as HEV-C1. However, epizootiological information about HEV-C1 is limited. To address this issue, serum samples from 443 small mammals captured at 5 sites in Hanoi, Vietnam, were examined for anti-HEV-C1 IgG antibodies. In addition, livers of seropositive animals were examined for viral RNA. Anti-HEV-C1 antibodies were detected in 57 (12.9%) of the 443 serum samples. Seropositive animals were found in all of the sites (4.7% to 22.2%). Anti-HEV-C1 antibodies were detected from 48 (12.3%) of 389 Rattus norvegicus and 9 (19.6%) of 46 R. tanezumi, but were not detected from 8 Suncus murinus. Viral RNAs were detected from 13 (22.8%) of the 57 seropositive rodents. The detection rate of viral RNA in seropositive R. tanezumi (66.7%, 6/9) was significantly higher than that in seropositive R. norvegicus (14.6%, 7/48). The results suggest that R. tanezumi is more susceptible than R. norvegicus to HEV-C1 infection. Phylogenetic analysis revealed that Vietnamese strains were divided into 3 clusters in genetic group 2 of HEV-C1. Multiple clusters of viruses were detected at several sites without species specificity, suggesting that 3 clusters of HEV-C1 co-circulate in Hanoi, Vietnam.

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

“…Since 2010, HEV-C1 RNA and antibodies have gradually been detected in rats on the Eurasian continent, North American continent, and the Indonesian archipelago [6,19,20,21,22,23,24,25]. This study further documents the rst detection of HEV-C1 in rats in Taiwan, a geographically isolated island.…”

“…Overall, we observed that 52% of wild rats were seropositive for rat HEV in international ports in Taiwan. This prevalence rate is higher than that of early studies, including 4.1-18.1% in Indonesia [19,20], 12.9% in Vietnam [21], 23.3% in China [22], 24.5% in Germany [23], 27.9% in Japan [24], and 31.2% in Lithuania [25]. However, the seropositive rates between studies might be di cult to directly compare due to the lack of identical antigens and detection antibodies used in the ELISA tests.…”

Synanthropic rodents as virus reservoirs and transmitters

“…In Vietnam, animals captured at bus stations and hospitals have tested positive for rat HEV 48 . These findings are supported by serological evidence from domestic animals and rodents in other studies 45,49,50 .…”

Orthohepevirus C: An Expanding Species of Emerging Hepatitis E Virus Variants

“…In Japan, the rates were 31.5% (114/362) from 2000 through 2002, while another study with unreported sample collection dates resulted in 28.6% seroprevalence (16/56) [22,23]; in Germany, the seroprevalence was 24.5% (36/147) between 2007 and 2010 [24], comparable to China with 27.8% (64/230) between 2011 and 2012 [25]. In Vietnam, two separate studies revealed similar seroprevalences of 20.3% (25/123) and 22.3% (21/94) in 2011 and an additional study between 2012 and 2013 demonstrated a lower seroprevalence of 12.3% (48/389) [26][27][28]. In a recent study in Lithuania, the seroprevalence was 31.2% (34/109) between 2014 and 2017; however, data were derived from both Norway rats (27) and Black rats (82) and individual species rates were not indicated [29].…”

“…Three studies in Vietnam found anti-HEV seroprevalences in Rattus tanezumi (Oriental house rat) of 25.0% (4/16) and 33.3% (2/6) in 2011 and 19.6% (9/46) between 2012 and 2013 [26][27][28]. In a large-scale investigation of sera of wild rats in China between 2011 and 2012, anti-HEV IgG rates in the species Rattus rattoides losea (Losea rat), Rattus flavipectus (Yellow-breasted rat), Rattus rattus hainanus, and Bandicota indica (Greater bandicoot rat), were 21.5% (26/121), 19.9% (34/171), 11.8% (2/17), and 23.0% (40/174), respectively [25].…”