%0 Journal Article
%T Prevalence of four different subgenotypes of genotype 4 hepatitis E virus among swine in the Shanghai area of China
%A Yijia Yan
%A Wen Zhang
%A Quan Shen
%A Li Cui
%A Xiuguo Hua
%J Acta Veterinaria Scandinavica
%D 2008
%I BioMed Central
%R 10.1186/1751-0147-50-12
%X 480 swine faecal specimens were collected from 23 farms which distribute all over Shanghai from September to November, 2007 and tested for the presence of HEV RNA by the polymerase chain reaction (PCR).Our results showed that 26.1% (6/23) of the swine farms were positive for HEV RNA and the positive rate of the six farms were ranged from 9.1% to 33.3%. The HEV RNA positive rate for total samples were 5% (24/480). The resulted positive band specific for HEV was sequenced and sequence analysis indicated that all of these isolates belonged to genotype 4 HEV. Phylogenetic analysis showed that the 24 isolates clustered into 4 distinct subgroups, sharing 83.3¨C89.7% inter-subgroup and 97¨C99% intra-subgroup identities. More over, isolates in three of the four subgroups closely clustered with previous identified strains, sharing up high to 97% identity with them.These results suggested that there were 4 different subgenotypes of HEV prevalent in Shanghai, and some of them may not be indigenous to Shanghai but introduced from other geographic regions.Hepatitis E virus (HEV), a member of the genus Hepevirus, is a non- enveloped virus with a positives- stranded RNA genome approximately7.2 kb in length [1]. HEV has been proven to transmit by the faecal- oral route, and outbreaks of hepatitis E are attributed to water contaminated with HEV. HEV and antibodies to HEV have been reportedly found in a wide variety of animals, especially swine [2-5]. A hypothesis has arisen that zoonosis is involved in the transmission of HEV, especially for the cases in non- endemic areas. Recently, more direct evidences for zoonotic HEV transmission were reported [6]The first animal strain of HEV, designated swine HEV, to be isolated and characterized was obtained from a pig in the United States [7]. Subsequently, many HEV samples from swine in over a dozen countries have been identified. HEV isolates were divided into four distinct genotypes according to sequence and phylogenetic analyses. Genotype
%U http://www.actavetscand.com/content/50/1/12