Epidemiological distribution of genotypes and sub-genotypes of hepatitis B virus in 15 ethnic groups in China / 中华流行病学杂志

Objective: To understand the distribution of genotypes and sub-genotypes of HBV in different ethnic groups in China. Methods: The HBsAg positive samples were selected by stratified multi-stage cluster sampling from the sample base of national HBV sero-epidemiological survey in 2020 for the amplification of S gene of HBV by nested PCR. A phylogeny tree was constructed to determine the genotypes and sub-genotypes of HBV. The distribution of genotypes and sub-genotypes of HBV were analyzed comprehensively by using laboratory data and demographic data. Results: A total of 1 539 positive samples from 15 ethnic groups were successfully amplified and analyzed, and 5 genotypes (B, C, D, I and C/D) were detected. The proportion of genotype B was higher in ethnic group of Han (74.52%, 623/836), Zhuang (49.28%, 34/69), Yi (53.19%, 25/47), Miao (94.12%, 32/34), Buyi (81.48%, 22/27). The proportions of genotype C were higher in ethnic groups of Yao (70.91%, 39/55). Genotype D was the predominant genotype in Uygur (83.78%, 31/37). Genotype C/D were detected in Tibetan (92.35%,326/353). In this study, 11 cases of genotype I were detected, 8 of which were distributed in Zhuang nationality. Except for Tibetan, sub-genotype B2 accounted for more than 80.00% in genotype B in all ethnic groups. The proportions of sub-genotype C2 were higher in 8 ethnic groups, i.e. Han, Tibetan, Yi, Uygur, Mongolian, Manchu, Hui and Miao. The proportions of sub-genotype C5 were higher in ethnic groups of Zhuang (55.56%, 15/27) and Yao (84.62%, 33/39). For genotype D, sub-genotype D3 was detected in Yi ethnic group and sub-genotype D1 was detected in both Uygur and Kazak. The proportions of sub-genotype C/D1 and C/D2 in Tibetan were 43.06% (152/353) and 49.29% (174/353). For all the 11 cases of genotype I infection, only sub-genotype I1 was detected. Conclusions: Five genotypes and 15 sub-genotypes of HBV were found in 15 ethnic groups. There were significant differences in the distribution of genotypes and sub-genotypes of HBV among different ethnic groups.

Intranasal Immunization Using CTA1-DD as a Mucosal Adjuvant for an Inactivated Influenza Vaccine / 生物医学与环境科学（英文）

OBJECTIVE@#To evaluate the effect of intranasal immunization with CTA1-DD as mucosal adjuvant combined with H3N2 split vaccine.@*METHODS@#Mice were immunized intranasally with PBS (negative control), or H3N2 split vaccine (3 μg/mouse) alone, or CTA1-DD (5 μg/mouse) alone, or H3N2 split vaccine (3 μg/mouse) plus CTA1-DD (5 μg/mouse). Positive control mice were immunized intramuscularly with H3N2 split vaccine (3 μg/mouse) and alum adjuvant. All the mice were immunized twice, two weeks apart. Then sera and mucosal lavages were collected. The specific HI titers, IgM, IgG, IgA, and IgG subtypes were examined by ELISA. IFN-γ and IL-4 were test by ELISpot. In addition, two weeks after the last immunization, surivival after H3N2 virus lethal challenge was measured.@*RESULTS@#H3N2 split vaccine formulated with CTA1-DD could elicit higher IgM, IgG and hemagglutination inhibition titers in sera. Furthermore, using CTA1-DD as adjuvant significantly improved mucosal secretory IgA titers in bronchoalveolar lavages and vaginal lavages. Meanwhile this mucosal adjuvant could enhance Th-1-type responses and induce protective hemagglutination inhibition titers. Notably, the addition of CTA1-DD to split vaccine provided 100% protection against lethal infection by the H3N2 virus.@*CONCLUSION@#CTA1-DD could promote mucosal, humoral and cell-mediated immune responses, which supports the further development of CTA1-DD as a mucosal adjuvant for mucosal vaccines.

Efficient Humoral and Cellular Immune Responses Induced by a Chimeric Virus-like Particle Displaying the Epitope of EV71 without Adjuvant / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To eliminate the side effects of aluminum adjuvant and His-tag, we constructed chimeric VLPs displaying the epitope of EV71 (SP70) without His-tagged. Then evaluating whether the VLPs could efficiently evoke not only humoral but also cellular immune responses against EV71 without adjuvant.</p><p><b>METHODS</b>The fusion protein was constructed by inserting SP70 into the MIR of truncated HBcAg sequence, expressed in E. Coli, and purified through ion exchange chromatography and density gradient centrifugation. Mice were immunized with the VLPs and sera were collected afterwards. The specific antibody titers, IgG subtypes and neutralizing efficacy were detected by ELISA, neutralization assay, and EV71 lethal challenge. IFN-γ and IL-4 secreted by splenocytes were tested by ELISPOT assay.</p><p><b>RESULTS</b>HBc-SP70 proteins can self-assemble into empty VLPs. After immunization with HBc-SP70 VLPs, the detectable anti-EV71 antibodies were effective in neutralizing EV71 and protected newborn mice from EV71 lethal challenge. There was no significant difference for the immune efficacy whether the aluminum adjuvant was added or not. The specific IgG subtypes were mainly IgG1 and IgG2b and splenocytes from the mice immunized produced high levels of IFN-γ and IL-4.</p><p><b>CONCLUSION</b>The fusion proteins without His-tagged was expressed and purified as soluble chimeric HBc-SP70 VLPs without renaturation. In the absence of adjuvant, they were efficient to elicit high levels of Th1/Th2 mixed immune response as well as assisted by aluminum adjuvant. Furthermore, the chimeric VLPs have potential to prevent HBV and EV71 infection simultaneously.</p>

Hepatitis B Immunoprophylactic Failure and Characteristics of the Hepatitis B Virus Gene in Mother-Infant Pairs in Parts of China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To determine the hepatitis B immunoprophylactic failure rate in infants born to hepatitis B virus (HBV) infected mothers and to characterize HBV genes.</p><p><b>METHODS</b>HBV-serological testing was conducted for pregnant women and infants. The complete genomes of 30 HBV isolates were sequenced, and genetic characteristics were analyzed using MEGA 5 software.</p><p><b>RESULTS</b>The immunoprophylactic failure rate for infants who had completed the scheduled hepatitis B vaccination program was 5.76% (32/556). High sequence homology (99.8%-100%) was observed in 8 of the 10 mother-infant pairs. We identified 19 subgenotype C2 strains, 9 subgenotype B2 strains, and 2 subgenotype C1 strains. Three serotypes were detected: adr (19/30), adw (9/30), and ayw (2/30). The frequency of amino acid mutation of the 'a' determinant region was 16.67% (5/30), including that of Q129H, F134Y, S136Y, and G145E. We detected 67 amino acid mutations in the basal core promoter, precore, and core regions of the genome.</p><p><b>CONCLUSION</b>The immunoprophylactic failure rate in infants born to HBV-infected mothers is low in the regions of China examined during this study. Moreover, HBV mutation in the 'a' determinant region could not account for immunoprophylactic failure for all infants.</p>

Expression and Purification of Recombinant Hepatitis Delta Virus (HDV) Antigen for Use in a Diagnostic ELISA for HDV Infection Using the High-Density Fermentation Strategy in Escherichia coli / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>Hepatitis Delt a Virus (HDV) antigen is widely used as a capture antigen in ELISAs for the identification of HDV infection; large amounts of recombinant HDV antigen with active antigenicity are required for this purpose.</p><p><b>METHODS</b>Reconstruct the gene of HDV antigen based on the bias code of Escherichia coli, the recombinant protein expresses by high-density fermentation with fed-batch feeding strategy, and purify by immobilized metal chromatography. The sensitivity and specificity of this antigen detect by ELISA method.</p><p><b>RESULTS</b>The expression of HDV antigen can reach 20% of the total cell mass in the soluble form. The recombinant HDV antigen can be conveniently purified (98%) by immobilized metal ion affinity chromatography (IMAC) using the interaction between a His-tag and nickel ions. Production of recombinant HDV antigen can reach 0.5 g/L under conditions of high-density cell fermentation. Applied to the diagnostic ELISA method, the recombinant HDV antigen shows excellent sensitivity (97% for IgM and 100% for IgG) and specificity (100% for IgG and IgM) for the detection of anti-HDV antibodies.</p><p><b>CONCLUSION</b>Expression and purification the recombinant HDV antigen as a candidate protein for application in a diagnostic ELISA for HDV infection. Large-scale production of the protein can be achieved using the high-density fermentation strategy.</p>

Construction of cDNA infectious clones of EV71 highly-pathogenic and cell-culture-adapted strains / 病毒学报

The highly-pathogenic EV71 strain is the primary cause of mortality in hand-foot-and-mouth disease (HFMD) associated with neurological symptoms, for which no clinically effective drugs or vaccines exist. This study aimed to construct infectious cDNA clones of the EV71 highly-pathogenic strain and the cell-culture adapted strain using a reverse genetics approach. The genomic RNAs of EV71 parent strains were used as the templates for RT-PCR amplification, and then the PCR products that overlapped the full-length genome were connected into the pBR322 vector to produce infectious clones of pEV71 (HP) and pEV71 (CCA), respectively. The results showed that the HP strain propagated much more quickly than the CCA strain. The rescued viruses derived from the infectious clones not only maintained their consistency with their parent strains in terms of genomic sequences, but also retained their respective biological phenotypes. This research will contribute to our understanding of EV71 pathogenesis and the development of novel vaccines against HFMD.

Prokaryotic soluble expression of protein D of Haemophilus influenzae type b / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To express the recombinant D protein in prokaryotic expression system solubly and make preparation for producing D-carrier conjugate vaccine next step.</p><p><b>METHODS</b>The hpd gene fragment removed of signal peptide from genomic DNA of Hib CMCC was inserted into pET43. 1a. The recombinant plasmid was transformed to competent E. coli BL21 (DE3) for expression under induction of IPTG. The expressed recombination protein was precipitated with ammonium sulfate, purified by DEAE anion exchange column chromatography and identified for reactogenicity by Western Blot.</p><p><b>RESULTS</b>The expressed recombination protein, in a soluble form, constained about 50% of total somatic protein and showed specific reaction with the HIB antisera after preliminary purification.</p><p><b>CONCLUSION</b>The D protein recombined expression plasmid was constructed successfully and expressed D protein in prokaryotic cells in a solube form.</p>

Construction of recombinant CHO cell strain for high expression of HBsAg / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To overexpress hepatitis B virus S gene in CHO cells cultured in serum-free media.</p><p><b>METHOD</b>Plasmid was constructed by cloning of HBV S gene and then it was transfected into CHO cells. After cell screen, the positive clones were identified and isolated into a serum-free media followed by the serological and morphological characterization of the expression product.</p><p><b>RESULT</b>CHO cell strains which can express HBsAg efficiently and stably were obtained. Spherical and filamentous HBsAg could be detected under electronic microscope. The titer of the expression product was up to 1:5000.</p><p><b>CONCLUSION</b>Serum-free media cultured CHO cell strain for overexpression of HBsAg was successfully constructed and the expression product was high antigenic.</p>

Antigenic analysis of two chimeric hepatitis B core particles presenting the preS1 neutralizing epitopes / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To construct full-length hepatitis B core particles presenting preS1 aa 21-47 epitope and truncated core particles presenting preS1 aa 37-45 epitope on their surface and compare their antigenicity.</p><p><b>METHODS</b>PreS1 aa21-47 epitope and aa 37-45 epitope were inserted respectively into full-length hepatitis B core (aa 1-183) and truncated HBcAg (aa 1-144), between the 78th (Asp) and 79th (Pro). The genes synthesized after the codon optimization were ligated to the pET43. 1a vector with the same cohesive terminal (NdeI and XhoI) and expressed in the E. coli expression system. The morphology of the proteins of interest were observed by electron microscope and characterized by ELISA and Western Blotting.</p><p><b>RESULTS</b>The morphology of the virus-like particles were confirmed by electron microscope. H2 were solid particles with a diameter of (31.61 +/- 1.27) nm, while H3 were hollow particles with a diameter of (28.46 +/- 1.16) nm. Statistical analysis showed that H2 is larger than H3 in the diameter (P < 0.01). The antigenicity of the inserted epitopes and carrier protein were identified by ELISA and Western Blotting.</p><p><b>CONCLUSION</b>Chimeric hepatitis B core particles presenting the preS1 neutralizing epitopes on their surface have been expressed, purified and identified, which lays the foundation for its application in vaccine research.</p>

Prokaryotic expression and characterization of two recombinant receptor-binding domain(RBD) proteins of human coronavirus NL63(HcoV-NL63) / 病毒学报

The receptor-binding domain(RBD) protein of HCoV-NL63 is a major target in the development of diagnostic assay and vaccine, it has a pivotal role in receptor attachment, viral entry and membrane fusion. In this study, we prepared 2 purified recombinant HCoV-NL63 RBD proteins using in E. coli system and identified the proteins by Western blotting. We first optimized codon and synthesized the RL (232-684aa)coding gene, then amplified the RL or RS(476-616aa) coding gene via PCR using different primers . The RL or RS coding gene was cloned into the pM48 expression vector fused with TrxA tag. The RBD (RL and RS) of HCoV-NL63 were expressed majorly as inclusion body when expressed in E. coli BL21pLys S under different conditions. The expressed products were purified by affinity chromatography then analyzed by SDS-PAGE and Western blotting. Our results showed that the recombinant RBD proteins were maximally expressed at 37 degrees C with 0. 8mM IPTG induction for 4h. RL or RS protein with 95 % purity was obtained and reacted positively with anti-sera from mice immunized with the recombinant vaccinia virus (Tiantan strain) in which HCoV-NL63 RL or RS protein was expressed. In conclusion, the purified recombinant RBD proteins(RL and RS)derived from E. coli were first prepared in China and they might provide a basis for further exploring biological role and vaccine development of HCoV-NL63.

Study on the risk of HBV infection among spouses of HBsAg carriers / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the risk of HBV infection among the spouses of hepatitis B virus surface antigen (HBsAg) carriers and to provide a reference for developing strategies on hepatitis B control and prevention.</p><p><b>METHODS</b>A case-control study including HBsAg carriers aged 20 - 45 years-old from the nationwide sero-epidemiological survey for Hepatitis B in both Guangdong and Jiangxi provinces in 2006, together with their spouses were selected as case group, while. HBsAg negative persons and their spouses were among the control groups, under the same residential areas, gender, age and age of marriage to the HBsAg carriers. Questionnaire survey and hepatitis B serological markers detection were carried out, together with the HBV genotype detection among the HBsAg positive couples between husband and wife by PCR.</p><p><b>RESULTS</b>Among the spouses of HBsAg carriers, the positive rate of HBsAg was 13.21%, while the rate was 6.29% for the spouse of HBsAg negative population, with difference statistically significant (χ² = 4.23, P < 0.05). HBsAg positive rate among spouses of the case group was higher than that in the control group. Among the spouses of HBsAg carriers, the HBsAg rate was positively correlated with the age of marriage, frequency of sexual intercourse and condom use. There were 21 pairs of HBsAg carriers between husband and wife, and HBV were isolated among 13 pairs, and there were 11 pairs carrying the same HBV genotype, accounting for 84.62%. HBV genotypes would include 8 pairs of type B and 3 pairs of type C. However, only 2 pairs were infected with different HBV genotype.</p><p><b>CONCLUSION</b>High risks of HBV infection existed in the spouses of HBsAg carriers. It was important to ask the HBsAg carriers to take the initiative in informing their spouses, and carrying out the appropriate measures, such as safe sex or timely hepatitis B vaccination for the spouse of HBsAg carriers etc., so as to reduce the HBV transmission between husband and wife.</p>

The investigation of hepatitis D virus infection situation in the human with HBsAg in Foshan of Guangdong province / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the seroprevalence of hepatitis D virus in Foshan of Guangdong province, to provide the data for the study about it in China.</p><p><b>METHODS</b>ELISA kits from two different companies were used for detecting anti-HDV IgG of all the serum samples, and then RT-PCR was carried out about the selected serum to ensure the results. All the serum samples were collected in 2011 in The First People's Hospital of Foshan.</p><p><b>RESULTS</b>The results from two ELISA kits and RT-PCR were identical. Eight samples were positive.</p><p><b>CONCLUSIONS</b>The seroprevalence rate of HDV in Foshan is higher than that in China. It has no statistically significant difference between female and male. Morever, the older with HBsAg are susceptible to HDV.</p>

Hepatitis A virus mimotope mapping by phage display peptide library / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>A 12 mer phage display peptide library was used to identify hepatitis A virus mimotopes of antigenic determinants, to provide the feasibility of virus epitope mapping by using this approach.</p><p><b>METHODS</b>Using purified anti-hepatitis A virus monoclonal antibody as affinity selective molecule, phage display peptide library was biopanned and positive clones were selected by ELISA, competition assay and DNA sequencing.</p><p><b>RESULTS</b>10 ELISA positive clones were chosen for DNA sequencing, and the displayed peptide sequences were deduced. 9 of them showed identical nucleotide sequence, and similarity in their amino acid sequence with VP1 of HAV HM175 was found, but no sequence homology was found between the other phage clone and the capsid proteins of HAV. Those peptides may behave as mimotopes of HAV.</p><p><b>CONCLUSION</b>The mimotope of HAV was selected by using phage display peptide library screening. The results provide the potential of this method to search for the mimotopes of the virus.</p>

Detection of hepatitis A virus RNA with an improved loop-mediated isothermal amplification assay / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To establish a novel improved loop-mediated isothermal amplification (LAMP) technique to detect hepatitis A virus (HAV).</p><p><b>METHODS</b>A novel improved LAMP assay based on the addition of an acceleration primer was developed for hepatitis A virus nucleotide acid detection.</p><p><b>RESULTS</b>Precision and reproducibility analysis proved its high stability and reliability. Comparison between the improved and conventional LAMP assays revealed that the former was more sensitive with a detection limit of 5 TCID50/ml. The novel detection method displayed 100% consistency with the TaqMan real-time PCR assay when applied to clinical specimens collected from patients with confirmed acute HAV infection.</p><p><b>CONCLUSION</b>This novel technique is widely applicable as a simple diagnostic tool in the clinical field as well as for the surveillance and investigation of the infectious disease in developing countries where HAV is endemic.</p>

Establishment and application of TaqMan real-time RT-PCR for the detection of hepatitis E virus / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To establish a specific TaqMan-based Real-time PCR assay for the detection of hepatitis E virus (HEV).</p><p><b>METHODS</b>According to the references, primers-probe sets which were located in ORF2, the conservative part of HEV genome were designed and therefore we established a HEV TaqMan real-time RT-PCR assay with great performance of specificity, sensitivity and reproducibility. And then it was used in the detection of HEV RNA in clinical samples.</p><p><b>RESULTS</b>The HEV Real-time RT-PCR assay established in this study were able to detect HEV RNA with a detection limit of 10 copies/reaction. When the detection of a same sample was repeated for several times, coefficients of variation (CV) was all less than 1.53%. Our data also suggested that there were 1.87 x 10(6)-8.12 x 10(9) RNA copies in 1 ml of the clinical samples.</p><p><b>CONCLUSION</b>The TaqMan-based Real-time PCR assay established in this study was specific and precise for the rapid detection of HEV RNA. It was applied successfully in the pathogen detection of clinical samples.</p>

The assemblage, purification and characterization of EV71 VLPs expressed in baculovirus / 病毒学报

To construct a recombinant expression plasmid Bacmid-P1-3CD containing the P1 and 3CD genes of enterovirus 71(EV71), the P1 and 3CD genes were cloned into the same baculovirus shuttle vector (Bacmid). Recombinant AcMNPV-P1-3CD was obtained by transfecting the Bacmid-P1-3CD into the insect cell line of S f9. With the IFA and Western-blot methods for identification of expression products confirmed that the target protein was expressed in interior of infected S f9 cells. Electron microscopy showed that the structural protein capsid P1 was cut by virus-encoded protease 3CD and assembled into EV71 virus like particles (VLPs) about 27nm diameter. Different values of MOI and time points of expression were compared to explore the optimal expression condition, and the results showed that the time point could be a more important factor. Then we used S f9 cells with serum-free medium in CellSTACK-10 Culture Chambers to produce EV71 VLPs in the confirmed condition. After purification of VLPs by density gradient centrifugation, we observed on SDS-PAGE profile the purified sample contained three major proteins whose molecular masses corresponded to those of VP1 (39kD), VP0 (34kD) and VP3 (26kD) as well as the intact structure, which can be greatly used for further study in protein structure and genetic engineering vaccine research.

Establishing a high-titer infectious avian influenza A (H5N1) pseudotyped viral particle / 病毒学报

A transient four-plasmid cotransfection system was used to construct avian influenza A (H5N1) pseudotyped viral particle (H5N1Pp) by incorporating hemagglutinin (HA) protein and neuraminidase (NA) protein from H5N1 avian influenza virus onto Murine leukemia virus pseudotyped viral particles, the transmission electron microscopy, infectivity titer assay, hemagglutination assay, neutralization assay of H5N1Pp were studied. We established a pseudotyped H5N1 viral particle at a high titer of 10(8) Pp/mL, the morphology,the hemagglutination activity and neutralization specificity of H5N1Pp is simililar to wild H5N1 virus. The research result sets a platform for studying this virus, including its receptors, the functional analysis of HA and NA, neutralizing antibodies and anti-H5N1 drug development.

Establishment and application of TaqMan real-time RT-PCR for the detection of hepatitis A virus / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To establish a specific TaqMan-based Real-time PCR assay for the detection of hepatitis A virus in serum samples.</p><p><b>METHODS</b>According to the references, primers-probe sets which were located in 5'-NCR, the most conservative part of HAV genome were designed and therefore we established a TaqMan real-time RT-PCR assay with great performance of specificity, sensitivity and reproducibility. And then it was used in the detection of HAV RNA in serum from HAV patients.</p><p><b>RESULTS</b>The HAV Real-time RT-PCR assay established in this study were able to detect HAV RNA and its detection limit ranged from 0.1CCID50/reaction to 0.01CCID50/reaction. When the detection of a same sample was repeated for three times, coefficients of varistion (CV) of intra- and inter-assay were calculated and they were all less than 2.0% and 2.6% respectively. Our data suggested that there were 5.18 x 10(2) - 4.93 x 10(7) RNA copies in 1 ml of the serum from acute HAV patients.</p><p><b>CONCLUSION</b>The TaqMan-based Real-time PCR assay established in this study was specific and precise for the rapid detection of HAV RNA. It was applied successfully in the pathogen detection of clinical samples.</p>

Effect of gene optimization on the expression and purification of HDV small antigen produced by genetic engineering / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To study the effect of gene optimization on the expression and purification of HDV small antigen produced by genetic engineering.</p><p><b>METHODS</b>Based on the colon preference of E. coli, the HDV small antigen original gene from GenBank was optimized. Both the original gene and the optimized gene expressed in prokaryotic cells, SDS-PAGE was made to analyze the protein expression yield and to decide which protein expression style was more proportion than the other. Furthermore, two antigens were purified by chromatography in order to compare the purity by SDS-PAGE and Image Lab software.</p><p><b>RESULTS</b>SDS-PAGE indicated that the molecular weight of target proteins from two groups were the same as we expected. Gene optimization resulted in the higher yield and it could make the product more soluble. After chromatography, the purity of target protein from optimized gene was up to 96.3%, obviously purer than that from original gene.</p><p><b>CONCLUSION</b>Gene optimization could increase the protein expression yield and solubility of genetic engineering HDV small antigen. In addition, the product from the optimized gene group was easier to be purified for diagnosis usage.</p>

Antibody detection of hepatitis E virus in human population of different national in China / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the seroprevalence of HEV infection in different national human population in Han, Hui and Zang in China.</p><p><b>METHODS</b>EIA was used for detecting anti-HEV IgG of the serum samples. All samples were collected in 2006-2008 in Sichuan, Beijing, Heilongjianin, Sandong, Gansuo, Ningxia and Qinghai areas.</p><p><b>RESULTS</b>The total positive rate of anti-HEV IgG was 17.97% (1878/ 10448), 24.32% (1794/7376) in Han national, 3.59% (81/2258) of Hui national and 0.37% (3/814) of Zang national, respectively. The positive rate of Han human at different age group, was 5.19% of < or = 10 year, 11.64% of 11-20 year, 20.08% of 21-30 year, 34.17% of 31-40 year, 41.75% of 41-50 year, 48.58% of 51-60 year, 57.43% of > or = 61 year. The positive rate of Hui human at different age group, was 3.11%, 3.96%, 2.11%, 3.98, 2.52%, 4.57% and 6.67%, respectively. Three positive of Zang human was between 21-60 year.</p><p><b>CONCLUSIONS</b>The HEV infection in Han national population was higher than the Hui and Zang national, significantly. The HEV infection was correlation with age significantly, the infection rate was increased with age.</p>