Human and swine hepatitis E viruses from Western India belong to different genotypes.
OBJECTIVE
Hepatitis E is endemic in India. Earlier, we showed prevalence of IgG antibodies to hepatitis E virus (IgG-anti-HEV) in different animal species and inability of at least one human hepatitis E virus (HEV) strain to infect pigs. In the US where hepatitis E is not endemic in humans, zoonotic spread of HEV was suspected as swine and human HEV were closely related and cross-species infection was documented. The present study attempts to identify and partially characterize swine HEV from India.


METHODS
Serum samples from 284 pigs were screened for the presence of HEV-RNA (nested polymerase chain reaction; PCR) and IgG-anti-HEV (enzyme-linked immunosorbent assay; ELISA). PCR products (Open Reading Frame-2 region) were sequenced and subjected to phylogenetic analysis. Two sero-negative pigs were inoculated with swine HEV-positive serum pool.


RESULTS
ELISA and PCR positivity were 42.9 and 4.6%, respectively. All Indian swine HEV sequences clustered with genotype IV. Pigs could be experimentally infected with swine HEV.


CONCLUSIONS
Swine HEV circulates in Indian pigs. In contrast to US and Taiwan wherein both human and swine HEV isolates belong to same genotype, Indian human HEV isolates belong to genotype I whereas genotype IV circulates in swine. Though experimental infection with Indian swine HEV was possible, at least one human HEV strain could not infect pigs.
Arankalle
Vidya A
VA
Hepatitis Division, National Institute of Virology, 20-A, Dr Ambedkar Road, 411001, Pune, India. aarankalle@hotmail.com
Chobe
Leenata P
LP
Joshi
Manohar V
MV
Chadha
Mandeep S
MS
Kundu
Biduth
B
Walimbe
Atul M
AM
D000595:Amino Acid Sequence; D000818:Animals; D005838:Genotype; D006508:Hepatitis Antibodies / Q000097:blood; D016751:Hepatitis E / Q000453:epidemiology* / Q000635:transmission / Q000662:veterinary*; D016752:Hepatitis E virus / Q000235:genetics* / Q000276:immunology; D006801:Humans; D007194:India; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000032:analysis; D016036:Seroepidemiologic Studies; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology* / Q000821:virology; D015047:Zoonoses / Q000453:epidemiology
D006508:Hepatitis Antibodies; D012367:RNA, Viral