| Objective Hepatitis E virus(HEV)is the pathogen of hepatitis E.Many studies have shown that some genotypes of HEV are prevalent in animals and can be transmitted across species to humans.To assess the zoonotic risk of HEV from domestic animals,the prevalences of HEV and the distribution of HEV genotypes in some species of domestic animals in Hebei Province were invesitigated and analyzed.Methods From October 2017 to May 2019,the feces of domestic animals including pigs,rabbits,cattle and sheep were collected from farms in different regions of Hebei Province;blood samples of pig and rabbit were collected from slaughterhouses;and pork,viscera of pig and other samples were collected from slaughterhouses and markets.HEV antigen(HEV-Ag),HEV antibody(HEV-Ab)and HEV nucleic acid(HEV RNA)were detected by using enzyme-linked immunosorbent assay(ELISA)and reverse transcriptase polymerase chain reaction(RT-nested PCR)respectively.HEV RNA PCR products were conducted for gene sequencing.HEV gene sequence alignment and gene evolution analysis were done by MEGA7.0 software.The statistical analyses were performed using SPSS 22(version 22.0;SPSS,Inc.,Chicago,IL).The?~2 test was used to determine whether there is a difference between expected prevalence/detection of HEV and the observed.Results having p-values of<0.05 were considered significant.Results(1)136 pig feces samples were collected from 6 pig farms in different regions of Hebei Province.4 pig farms had HEV-Ag and HEV-Ag positive samples,and the average positive rates of 136 pig manure samples HEV-Ag and HEV-RNA were 6.62%and 4.41%respectively;the positive rates HEV-RNA were 0.87%(1/115),6.33%(5/79)and 2.22%(2/90)for pig blood,liver and kidney samples collected at slaughterhouses.The positive rates of HEV-RNA were 6.14%(7/114),3.10%(4/129)and 1.18%(2/170)for the liver,kidney and blood products collected from the market,but the pork from the market and slaughterhouses is negative.(2)256 samples of rabbit feces were collected from 6 rabbit farms,and we found positive feces samples of HEV-Ag and HEV RNA in 5 farms from them.The average positive rates of 256 rabbit feces samples for HEV-Ag and HEV RNA were 14.06%and 11.33%respectively.Blood samples of 211 meat rabbits and 248 otter rabbits were collected in slaughterhouses.The positive rates of serum antibody were 2.84%and 15.49%respectively.The positive rates of HEV-Ag and HEV-RNA in meat rabbits were 1.9%and 0.95%respectively.The positive rates of HEV-Ag and HEV RNA in otter rabbits were 2.82%and2.42%respectively.(3)1 sample was positive in HEV-Ag of the 182 fecal samples from the cattle and 1 sample was positive in HEV-Ag of 97 fecal samples from the sheep.They are all collected from farms in different regions,but HEV-RNA in them was negative.47 horses,47foxes and 60 minks were detected,none of them was HEV-Ag or HEV RNA positive.(4)The analysis of gene sequence showed that all HEV from pigs belonged to HEV-4 and HEV from rabbit belonged to HEV-3.Conclusions This study shows that the HEV prevalence in pigs of Hebei Provinceis is common.A small portion of pigs at slaughter age are in the period of viremia of HEV infection,and the HEV detecte in swine viscera from slaughterhouse and market belonged to HEV-4,suggesting that the pig liver,kidney and other viscera purchased by consumers may contain HEV.If the viscera of pigs are not cooked thoroughly,there will be a risk of infection after eating.The study shows that the prevalence of HEV among rabbits in Hebei Province is relatively common.At slaughter sge,some rabbits were positive in HEV-3,suggesting that rabbit meat and rabbit meat products have the risk of transmission HEV.The prevalence of HEV in pigs and rabbits also makes the breeders and slaughterhouse workers exposed to the risk of HEV infection because of their close contact with pigs and rabbits.HEV antigen-positive samples appeared in cattle and sheep,but no HEV RNA was detected,and further investigation should be conducted.No HEV infection was found in other animals. |
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