Prevalence, isolation, and partial sequence analysis of hepatitis E virus from domestic animals in China

Abstract

Evidence that hepatitis E is zoonotic is accumulating. Serum samples were collected from pigs, cattle, and goats from various regions of China to determine whether they had been infected with hepatitis E virus (HEV). An in-house enzyme immunoassay (EIA) and reverse transcriptase-polymerase chain reaction (RT-PCR) with primers from open reading frame (ORF) 2 were used to detect anti-HEV antibodies and HEV RNA. The mean positivity rates of anti-HEV antibody for pigs and cattle were 78.8% and 6.3% but none of the goat sera were positive. Pigs may be more susceptible to infection with HEV than cattle or goats. Five of 263 pig sera were positive for HEV RNA and four of these five were also positive for anti-HEV. The PCR products (nt 6007-6354) were cloned and sequenced and compared to other HEV sequences in the nucleotide databases. The five sequences shared 83-93% identity to each other at the nucleotide level and 74-79%, 73-74%, 73-78%, and 83-99% identity to HEV genotypes 1, 2, 3, and 4, respectively. They were closely related to human isolates of HEV genotype 4. Phylogenetic analyses also place these swine sequences in HEV genotype 4, resembling most closely viruses isolated from Chinese patients with acute hepatitis. These data support the hypothesis that sporadic hepatitis E in China is zoonotic.

Molecular and serological characterization of sporadic acute hepatitis E in a Japanese patient infected with a genotype III hepatitis E virus in 1993

“…The infected patient in the current study also had no history of travel to areas endemic for HEV and did not report contact with persons who had travelled to endemic areas or contact with farm pigs or rodents, although there are accumulating lines of evidence that animals may act as natural hosts of HEV (Erker et al, 1999; Hsieh et al, 1999;Huang et al, 2002;Meng et al, 1997Meng et al, , 1998Pina et al, 2000;Wang et al, 2002;Wu et al, 2002). The increasing globalization of food markets and increased overseas travel for business and pleasure have increased the potential of introducing HEV from not only developing countries but also industrialized countries into Japan.…”

Hepatitis E Virus Infection among Animals and Humans in Xinjiang, China: Possibility of Swine to Human Transmission of Sporadic Hepatitis E in an Endemic Area

“…1,15,16 Moreover, partial or complete genomes of HEV were detected in deer, wild boar, mongoose. [17][18][19] Therefore, there should be some HEV animal reservoirs other than swine that cause zoonotic diseases in HEV-endemic areas.…”

Sporadic acute or fulminant hepatitis E in Hokkaido, Japan, may be food-borne, as suggested by the presence of hepatitis E virus in pig liver as food

“…Zoonotic spread of HEV has been suggested as human and swine HEV strains are closely related genetically (Erker et al, 1999;Hsieh et al, 1999;Huang et al, 2002;Meng, 2000;Meng et al, 1997Meng et al, , 1998Okamoto et al, 2001;Pina et al, 2000;Wang et al, 2002;Wu et al, 2002), and experimental cross-species infections of swine HEV to non-human primates and that of human HEV to swine have been demonstrated (Erker et al, 1999;Halbur et al, 2001;Meng et al, 1998). In our previous study, we found a high prevalence of swine anti-HEV IgG among Japanese pigs of 2-6 months of age (58 % or 1448/2500) (Takahashi et al, 2003) and identified a pair of Japanese swine and human HEV isolates (swJ13-1 and HE-JA1, respectively) of genotype IV with 99 % identity over the entire genome (Nishizawa et al, 2003).…”