Seroprevalence and evolutionary dynamics of genotype 4 hepatitis E virus in Shandong Province, China.

AIM: To investigate the seroprevalence and evolutionary dynamics of hepatitis E virus (HEV) and assess the ancestor of HEVs in China's Shandong Province. METHODS: A total of 2028 serum, 60 fecal and 82 bile samples were collected from the general human population, patients and swine, respectively. This seroepidemiological study was conducted using an immunnosorbent assay and HEV RNA was detected by the reverse transcription-nested polymerase chain reaction (RT-nPCR) method. Complete genome sequences of the prevalent strains (CH-YT-HEV01, CH-YT-HEV02 and CH-YT-sHEV01) were determined, and the sequences were analyzed phylogenetically. In addition, the evolutionary dynamics of three HEV isolates were determined using the framework of coalescent analysis in the program package BEAST, and the time of the most recent common ancestors (TMRCAs) of China-indigenous genotype 4 HEV isolates was calculated. RESULTS: The overall viral burden in the general human population was 0.1%, and the positive rates of anti-HEV IgG and IgM in the serum specimens were 25.1% (509/2028) and 2.3% (51/2028), respectively. In addition, IgG positivity increased with age. The phylogenetic analysis based on the full-length nucleotide sequences showed that the strain CH-YT-HEV02 was directly related to CH-YT-sHEV01 with a 94% identity, suggesting that they were involved in cross-species transmission. The isolate CH-YT-HEV01 was close to HB-3 and CHN-SD-sHEV with a bootstrap value of 100%, sharing a 96.1%-96.4% identity with each other. Surprisingly, the HB-3 strain was a representative strain prevalent in swine in Hubei, and the isolate CHN-SD-sHEV was obtained from swine in Shandong in a previous report. TMRCA for the clade of CH-YT-HEV01 and HB-3 was 2003, which was consistent with the TMRCA for the clade of CHN-SD-sHEV and HB-3, and they were both earlier than the TMRCA for the clade of CH-YT-HEV01 and CHN-SD-sHEV (2004). CONCLUSION: The strains CH-YT-HEV01, CHN-SD-sHEV and HB-3 are involved in trans-regional transmission, and the ancestors of HEVs in Shandong come from Hubei Province.

[The coastal areas of Yantai human and swine hepatitis E virus genotyping analysis].

OBJECTIVE: Survey of the coastal city of Yantai, from human and swine hepatitis E virus (HEV) genotype correlation. METHOD: Application of reverse transcription nested polymerase chain reaction (RT-nPCR) method for local acute sporadic hepatitis E patients,normal population of HEV-IgM positive and local pig farm pigs were HEV RNA detection. And HEV RNA positive samples for cloning sequencing and sequence analysis. RESULTS: In 16 patients with acute sporadic hepatitis E in 7 cases of RNA positive stool specimens of HEV; 51 IgM positive sera of normal people in specimens with 1 HEV RNA positive; 34 pig bile specimens with 1 HEV RNA positive. Sequence analysis revealed the region HEV strains and swine strains in the ORF2 region of nucleotide sequence homology is 87%-98.1%. 7 strains of hepatitis E virus genotype in patients and 1 strains of swine hepatitis E virus genotypes are type IV, gene sequence homology between the 87%-98.1%; there were 6 patients and porcine gene sequence homology in 93.9%-98.1% between,for type a subtype; 1 patients and porcine gene sequence homology in 87%, for the type D subtype. Normal population of 1 cases of hepatitis E virus genotype for I type D subtype. Human and porcine HEV ORF2 gene fragment and HEV part I-IV representative strains were compared, and the nucleotide sequence homology were 82.5%-100%, 81.7%-92.9%, 81.4%-93.9%, 84.9%-100%. CONCLUSION: The area population prevalence of HEV in the presence of 2 genotype 3 subtype genes, mainly to IV A, in pigs with popular HEV gene with a high homology; HEV type I in the crowd disperses in the presence of.

[Epidemiological study on risk factors of hepatitis E in Yantai, Shandong province].

OBJECTIVE: To study the prevalent characteristics and risk factors of viral hepatitis E in Yantai and the relative for strategy on viral hepatitis E control in the area. METHODS: Data on viral hepatitis E incidence reported by the Notifiable Infectious Disease Reporting System in 2005-2009 was analyzed. 2028 persons were chosen for hepatitis E virus (HEV) antibody detection by enzyme linked immunosorbent assay method. RT-nPCR method was applied to obtain the sequence of HEV in HEV cases. A case-control study was used to identify the risk factors of HEV infection. RESULTS: The distribution of HEV cases was sporadic in Yantai, and the annual incidence rate was 5.70/100 000, with spring as the prevalent season. Farmers were the main population involved and with those over the age of 40. Regional distribution was mainly along the coastline. Data from the sequential analysis showed that gene type of local patients was type 4 and healthy person whose HEV-IgM was positive was type l. Finding from the case-control study suggested that eating seafoods, living condition in the households and unhealthy habits played important roles in the infection of HEV. Results from multiple logistic regression showed that eating seafood, with eat-out history, drinking alcohol and un-boiled water were the main risk factors in the infection of HEV. CONCLUSION: The level of HE in Yantai will maintain in a high level, but there is no chance of epidemic outbreak of HE in large range. Population of incidence mainly concentrates on farmers.