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Objective: The aim of this study was to systemically analyze the epidemiologic, serological and genetic characteristics of hepatitis E virus (HEV) in Shanghai from 1997 to 2012., Methods: We analyzed the data related to the epidemics of hepatitis E from China Information System for Disease Control and Prevention. We implemented serological surveillance program, based on community healthy population with enzyme-linked immunosorbent assay method and estimated the standardized sero-prevalence. We also obtained nucleotide sequences of hepatitis E patients using the nested RT-PCT assays, together with prototype sequences in the GenBank to construct a HEV genetic database in Shanghai., Results: In this paper, we found that the distribution of hepatitis E patients was sporadic in the past 16 years in Shanghai. The morbidity kept declining, but with seasonal and periodical fluctuation. Morbidity in males was significantly higher than in females, with the hard hit population between 30 and 65 year-olds. In total, 3979 sera samples were collected through the serological surveillance programs in 2001, 2004, 2007 and 2012. The standardized sero-prevalence rates of the said years were 22.32%, 18.56%, 10.22% and 34.43% which all showing strong relationship with age groups and the regions where the populations were being monitored. 73 nucleotide sequences of hepatitis E patients from hospitals were identified, during 2004 and 2008., Results: from phylogenetic analysis revealed that all HEV isolates belonged to genotype IV and including 4 known subtypes 4a, 4d, 4h and 4i which sharing 83.09% - 97.96%, 85.87% - 97.26% and 83.80% - 95.10% nucleotide sequence identities with the swine HEV genotype IV of GU188851, DQ450072 and EF570133. Meanwhile, 59 HEV isolates from different districts shared 99% nucleotide sequence identities with each other., Conclusion: Hepatitis E would still be a challenge for long time and the zoonotic questions that related to hepatitis E, need to be explored and explained in the future.

Objective: Prevalence of occult hepatitis B virus (HBV) infection (OBI) was investigated in a paired mother-teenager population and HBV S gene variation including overt and occult HBV, was determined., Methods: A follow-up study based on an initial survey of 135 mother-teenager pairs was carried out through collection of questionnaires and blood samples HBsAg were detected by ELISA method, viral load by PCR amplification and HBV S gene by phylogenetic analysis., Results: 102 pairs of subjects were followed-up. Blood samples from 94 mothers and 101 children were collected. OBI prevalence in mothers was 10.0% (6/60), significantly higher than 2.0% (2/101) in teenagers. Medians of viral load were 399.9 IU/ml and 247.6 IU/ml in overt and occult HBV strains, but without significant difference. 1 occult HBV strain belonged to genotype B with serotype adw while the other 7 were genotype C with serotype adr. 15 of the overt HBV strains belonged to genotype B with serotype adw and the other 8 were genotype C with serotype adr. Proportions of genotype-C strains were significantly higher in occult HBV strains than in overt HBV strains., Conclusion: OBI was seen in teenage-mother population.

Objective: To determine the prevalence and genotype of hepatitis E virus (HEV) among commercial swine population in Eastern and Southern China., Methods: Six hundred specimens of swine bile collected from 5 slaughterhouses in Eastern and Southern China from 2007 to 2009 were tested for HEV RNA using nested RT-PCR. PCR products were sequenced for phylogenetic analysis., Results: Forty-seven out of the 600 samples (7.83%) were positive for HEV RNA. Based on the 150 nt fragment within HEV ORF2, data from phylogenetic analysis revealed that all the 47 HEV isolates were identified to be genotype IV, sharing 75.0% - 83.4%, 75.0% - 84.6%, 71.9% - 80.7% and 88.1% - 91.5% nucleotide identities with prototype I, II, III and IV HEV strains respectively while majority of the isolates clustered within their respective isolation sites., Conclusion: HEV was widespread in commercial swine population in Eastern and Southern China that raised a serious concern about the safety regarding the consumption of pork products.

Objective: To understand phylogenetic characteristics of sporadic hepatitis E virus (HEV) in eastern China., Methods: Four hundred and thirteen sera were collected from sporadic hepatitis E cases in 14 second- or first-class hospitals in Eastern China from 2005 to 2008 and detected with a nested RT-PCR assay. Partial nucleotide sequences of the HEV isolates were determined for phylogenetic analysis with prototype sequences in the GenBank., Results: The male-to-female sex ratio of the patients was 1.75:1 with 61.5% of them aged 40 - 69 years old. HEV RNA was detected in 140 out of 413(34%)serum samples. Phylogenetic analysis revealed that all the 140 HEV isolates belonged to genotype IV, sharing 77.9% - 88.3%, 80.8% - 90.6%, 73.4% - 85.2% and 91.0% - 95.4% nucleotide sequence identities with prototype I, II, III and IV HEV isolates respectively., Conclusion: It was evident that genotype IV HEV served as the main causative agent of sporadic HEV infection in Eastern China. However the viral origin and evolution needs further clarification.

Objective: To explore the carrier state of hepatitis E virus(HEV) in livestock in Xi'an area., Methods: Bile samples from swine, canine, sheep and cow were collected from a local slaughtering house. Reverse transcriptase nested polymerase chain reaction (RT-nPCR) was employed to amplify the ORF2 region in HEV RNA genome. All positive samples were sequenced and compared with data from GenBank. Homology analysis was conducted based on the outcome of sequencing., Results: 194, 178, 79 and 191 bile samples from swine, canine, cow and sheep were collected. Positive rates with RT-nPCR method in these domestic animals were 4.10%, 0%, 0% and 0% respectively. Genetic distance analysis indicated that strains being identified were close to genotype IV of HEV, then genotype I, II and III in nucleic acid. Same outcome was shown by the same analysis on amino acid., Conclusion: Swine was the only reservoir of HEV in livestock and genotype IV was the prevalent genotype.

Objective: To determine the prevalence and genotype of hepatitis E virus (HEV) in swine liver before on the market and to analyze the phylogenetic relationship between the isolates from swine and human., Methods: 35 swine liver specimens were collected from two slaughtering houses in the countryside of Shandong province, China. Nested reverse transcription-polymerase chain reaction (nested RT-PCR) and subsequent sequencing were used to determine the nucleotide sequences. A phylogenetic tree was constructed with Neighbor-joining method based on the Kimura-2-parameter model., Results: 3. (8.57%) of the 35 swine liver specimens being tested were positive for HEV RNA. The three swine HEV strains isolated in the present study from liver samples shared the highest identity to genotype-IV HEV., Conclusion: Results from the study confirmed that HEV was detectable among swine before on the market and the genotype was the same as that representing human and swine isolates in China. It also suggested that much more attention should be paid to the safety on the digestion of swine liver.

Objective: To ascertain the genetic characterization and genotype of measles viruses isolated in Shanghai region, in 2005., Methods: Measles virus was isolated from throat swab specimens collected from suspected measles cases and 450 bp fragment of C terminus of nucleprotein (N) gene was amplified by RT-PCR. Sequence analysis was conducted to ascertain the genotype and to compare the difference of nucleotide with other measles virus strain published in GenBank., Results: 4 measles viruses were isolated from 10 throat swab specimens, and the sequence analysis indicated that they belonged to H1 genotype. The homogeneity of 450 nucleotides in the C terminal of the N gene was at 98%-98.2% as compared to H1 genotype (China93-7). They differed from genotype H2 (China94-1) at 6.4%-6.9% and from genotype A (Edmonston) at 6.7%-6.9%, from measles vaccine (Shanghail91) at 7.6%-8.0%. They differed from the other measles viral strain isolated in China in 1993 - 2005 at 0.2%-3.7%. The variation within 4 isolated measles viruses was at 0.7%-1.3%., Conclusion: It was H1 genotype measles viruses,which are the native viruses in China that led to the outbreak of measles in Shanghai, in 2005.

Objective: To study the genotype of swines isolated from humans and their relationships with hepatitis E virus (HEV) in the rural areas of southern China., Methods: Specimens collected from normal people with HEV-IgM positive, acute hepatitis E patients and from swine in the same area were detected for HEV RNA using RT-nPCR with ORF2 primers. The positive PCR products were cloned and sequenced., Results: 13 out of the 132 samples from swine stool, 4 of 26 HEV-IgM positive sera of normal people and 1 of 4 acute hepatitis E patients' stool sample and sera were tested positive for HEV RNA. Data from sequence analysis showed that the identity at nucleotide level was 89.3%-100.0% among the 10 isolates which shared 78.7% - 84.7%, 83.3% - 85.3%, 76.0% - 80.0% and 84.7% - 95.3% nucleotide sequence identity with HEV genotype I, II, III and IV respectively in the region (nt6317- 6466)., Conclusion: HEV circulating in humans and swine in the area belonged to genotype IV.