[Show abstract][Hide abstract] ABSTRACT: Aim It is unclear whether a mother of negative hepatitis B surface antigen (HBsAg) but positive hepatitis B virus (HBV) is at potential risk for mother-to-child transmission of HBV. This study using a paired mother-teenager population aims to assess whether maternal HBsAg-negative HBV infection ((hn)HBI) is a significant source of child HBV infection (HBI).Methods A follow-up study with blood collection has been conducted on the 93 mother-teenager pairs from the initial 135 pregnant woman-newborn pairs 13 years after neonatal HBV vaccination. Serological and viral markers of HBV has been tested, and phylogenetic analysis of HBV isolates has been done.Results The HBI prevalence is 1.9% (1 (hn)HBI/53) for teenagers of non-HBI mothers, compared with 16.7% (1 (hn)HBI/6) for those of (hn)HBI mothers and 2.9% [1 HBsAg-positive HBV infection ((hp)HBI)/34] for those of (hp)HBI mothers. Similar viral sequences have been found in one pair of which both mother and teenager have had (hn)HBI. In comparison with the (hp)HBI cases, those (hn)HBI have a lower level of HBV viral load and a higher proportion of genotype-C strains, which are accompanied by differentiated mutations (Q129R, K141E and Y161N) of the "a" determinant of the HBV surface gene.Conclusion Our findings suggest that mother-to-teenager transmission of (hn)HBI can occur among those under neonatal HBV vaccination program.
Clinical and vaccine Immunology: CVI 12/2012; · 2.60 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study aimed at investigating mutations in the hepatitis B surface protein (HBsAg) in occult hepatitis B virus (HBV) infection (OBI) and their influence on viral antigenicity and phenotype.
The characteristics of 61 carriers with OBI (OBI group), 153 HBsAg(+) carriers with serum HBsAg ⩽100IU/ml (HBsAg-L group) and 54 carriers with serum HBsAg >100IU/ml (HBsAg-H group) from 38,499 blood donors were investigated. Mutations in the major hydrophilic region (MHR) of the viral sequences were determined. Thirteen representative MHR mutations observed in OBI sequences were antigenically characterized with a panel of monoclonal antibodies (MAbs) and commercial HBsAg immunoassays and functionally characterized in HuH7 cells and hydrodynamically injected mice.
Of 61 OBI sequences, 34 (55.7%) harbored MHR mutations, which was significantly higher than the frequency in either the HBsAg-L (34.0%, p=0.003) or the HBsAg-H group (17.1%, p<0.001). Alterations in antigenicity induced by the 13 representative MHR mutations identified in the OBI group were assessed by reacting recombinant HBV mutants with 30 different MAbs targeting various epitopes. Four out of the 13 mutations (C124R, C124Y, K141E, and D144A) strongly decreased the analytical sensitivity of seven commercial HBsAg immunoassays, and 10 (G119R, C124Y, I126S, Q129R, S136P, C139R, T140I, K141E, D144A, and G145R) significantly impaired virion and/or S protein secretion in both HuH7 cells and mice.
MHR mutations alter antigenicity and impair virion secretion, both of which may contribute to HBsAg detection failure in individuals with OBI.
Journal of Hepatology 05/2012; 57(4):720-9. · 9.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Hand-foot-and-mouth disease (HFMD) is caused mainly by the human enterovirus type 71 (HEV71) and the Coxsackievirus A group type 16 (CVA16). Large outbreaks of disease have occurred frequently in the Asia-Pacific region. Reliable methods are needed for diagnosis of HFMD in children. IgM-capture ELISA, with its notable advantages of convenience and low cost, provides a potentially frontline assay. We aimed to evaluate the newly developed IgM-capture ELISAs for HEV71 and CVA16 in the diagnosis of HFMD, and to measure the kinetics of IgM over the course of HEV71 or CVA16 infections.
We mapped, for the first time, the kinetics of IgM in HEV71 and CVA16 infection. HEV71- and CVA16-IgM were both detectable in some patients on day 1 of illness, and in 100% of patients by day 5 (HEV71) and day 8 (CVA16) respectively; both IgMs persisted for several weeks. The IgM detection rates were 90.2% (138 of 153 sera) and 68.0% (66 of 97 sera) for HEV71 and CVA16 infections, respectively, during the first 7 days of diseases. During the first 90 days after onset these values were 93.6% (233 of 249 sera) and 72.8% (91 of 125 sera) for HEV71 and CVA16 infections, respectively. Some cross-reactivity was observed between HEV71- and CVA16-IgM ELISAs. HEV71-IgM was positive in 38 of 122 (31.1%) CVA16 infections, 14 of 49 (28.6%) other enteroviral infections and 2 of 105 (1.9%) for other respiratory virus infected sera. Similarly, CVA16-IgM was apparently positive in 58 of 211 (27.5%) HEV71 infections, 16 of 48 (33.3%) other enterovirus infections and 3 of 105 (2.9%) other respiratory virus infected sera. Nevertheless, the ELISA yielded the higher OD450 value of main antibody than that of cross-reaction antibody, successfully identifying the enteroviral infection in 96.6% (HEV71) and 91.7% (CVA16) cases. When blood and rectal swabs were collected on the same day, the data showed that the agreement between IgM-capture ELISA and real-time RT-PCR in HEV71 was high (Kappa value = 0.729) while CVA16 somewhat lower (Kappa value = 0.300).
HEV71- and CVA16-IgM ELISAs can be deployed successfully as a convenient and cost-effective diagnostic tool for HFMD in clinical laboratories.
[Show abstract][Hide abstract] ABSTRACT: A novel hepatitis B virus (HBV) strain (W29) was isolated from serum samples in the northwest of China. Phylogenetic and distance analyses indicate that this strain is grouped with a series of distinct strains discovered in Vietnam and Laos that have been proposed to be a new genotype I. TreeOrderScan and GroupScan methods were used to study the intergenotype recombination of this special group. Recombination plots and tree maps of W29 and these putative genotype I strains exhibit distinct characteristics that are unexpected in typical genotype C strains of HBV. The amino acids of P gene, S gene, X gene, and C gene of all genotypes (including subtypes) were compared, and eight unique sites were found in genotype I. In vitro and in vivo experiments were also conducted to determine phenotypic characteristics between W29 and other representative strains of different genotypes obtained from China. Secretion of HBsAg in Huh7 cells is uniformly abundant among genotypes A, B, C, and I (W29), but not genotype D. HBeAg secretion is low in genotype I (W29), whose level is close to genotype A and much lower than genotypes B, C, and D. Results from the acute hydrodynamic injection mouse model also exhibit a similar pattern. From an overview of the results, the viral markers of W29 (I1) in Huh7 cells and mice had a more similar level to genotype A than genotype C, although the latter was closer to W29 in distance analysis. All evidence suggests that W29, together with other related strains found in Vietnam and Laos, should be classified into a new genotype.
PLoS ONE 01/2010; 5(2):e9297. · 3.73 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The characteristics of 30 carriers with occult hepatitis B virus (HBV) infection (OBI) were compared with those of 30 individuals diagnosed as being HBV carriers at the time of blood donation, 60 asymptomatic carriers, and 60 chronic hepatitis patients. The prevalence of genotype C was significantly higher in carriers with OBIs than in any other HBsAg-positive (HBsAg(+)) group (P < 0.001). Specific amino acid substitutions in the regions from amino acids 117 to 121 and amino acids 144 to 147 located in the major hydrophilic region of the S gene were associated with carriers with OBIs (P < 0.01 for carriers with OBIs versus HBsAg(+) donors, carriers with OBIs versus HBsAg(+) asymptomatic carriers, and carriers with OBIs versus HBsAg(+) chronic hepatitis patients). G145R was the major variation in the HBV isolates responsible for local occult HBV infections.
Journal of clinical microbiology 11/2009; 48(2):357-62. · 4.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A point prevalence study of hepatitis E virus (HEV) in Chinese blood donors was conducted, and the prevalences of antibodies against HEV immunoglobulin G (IgG) and IgM among Chinese blood donors were 32.60% and 0.94%, respectively. HEV viremia was 0.07%.
Journal of clinical microbiology 11/2009; 48(1):317-8. · 4.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A quantitative real-time PCR assay was developed to measure the proviral load of human T-lymphotropic virus type I (HTLV-I) in peripheral blood. The technology utilizes special primers and Taqman MGB fluorescence probe to measure amplification products from the gag-pro-pol polyprotein gene of HTLV-I. HTLV-I copy number was normalized to the amount of cellular DNA by quantitation of the beta-actin gene, The amplification system was sensitive to detect 5 copy/microL. The standard curve had a good linearity when the quantity for the gene was between 10(3) and 10(7) copy/microL (R2 = 0.999). Good reproducibility was observed in each intra- and inter-assay. We also measured proviral load in peripheral blood in 12 HTLV-I seropositive former blood donors. Proviral load for HTLV-I infected donors ranged from 0.015 to 12.819 copy/cell in WBC with the mean of 3.116 copy/cell.
Bing du xue bao = Chinese journal of virology / [bian ji, Bing du xue bao bian ji wei yuan hui] 09/2009; 25(5):339-43.
[Show abstract][Hide abstract] ABSTRACT: Occult hepatitis B virus (HBV) infection status of blood donors in a southern city in China was investigated by immunological assays and nucleic acid testing. Overall, 17 (0.19%, 95% CI: 0.11%-0.30%) of the 9023 HBsAg negative samples were found to be positive for the presence of HBV DNA. "A" epitope sequences were obtained from 14 among them. Mutation(s) in aa124-aa147 existed in 6 (42.9%, 6/14) samples and 4 (66.7%, 4/6)were G145R mutation. Ratio of genotype C in occult donors (10/17) was statistically higher than HBs-positive donors (0/15, P<0.01), which implied that HBV genotype C leaded to occult infection more easily.
Bing du xue bao = Chinese journal of virology / [bian ji, Bing du xue bao bian ji wei yuan hui] 05/2009; 25(3):178-84.
[Show abstract][Hide abstract] ABSTRACT: The candidate recombinant hepatitis E vaccine, HEV 239, protect monkeys against infection by hepatitis E virus (HEV). The safety and immunogenicity of the vaccine for humans was assessed in a randomized controlled phase II clinical trial. The study was conducted in an endemic area of southern China and consisted of a dose scheduling, involving 457 adults and a dose escalation component involving 155 high school students. The results showed that the vaccine is safe and immunogenic for humans and suggest that it could prevent new HEV infection.
[Show abstract][Hide abstract] ABSTRACT: Western blot, capture-PCR, blocking ELISA and synthetic polypeptides were used to systematically study the recognition epitopes on HEV ORF2 of 23 anti-HEV monoclonal antibodies(McAbs) which were previously generated in our laboratory directed against HEV ORF2. Results showed that seven McAbs recognized linear epitopes that located at aa408-458 of HEV ORF2 and 16 conformation-dependent McAbs, most of which recognized the surface epitopes of native HEV, located at aa459-606 of HEV ORF2. The systematical study of the recognition epitopes of anti-HEV McAbs on HEV ORF2 provides important information for the investigation of virus receptor and HEV infection mechanism, as well as its vaccine and diagnostics development.
Bing du xue bao = Chinese journal of virology / [bian ji, Bing du xue bao bian ji wei yuan hui] 07/2008; 24(2):83-7.
[Show abstract][Hide abstract] ABSTRACT: To evaluate two commercial anti-hepatitis E virus (HEV) IgM kits used for differential diagnosis of acute enteric viral hepatitis.
The kit for IgM capture assay, was produced with a recombinant HEV structural protein protecting primates against experimental infection by different HEV genotypes, while the other kit for indirect ELISA was produced with recombinant structural proteins from different HEV genotypes. The serum specimens were taken from 241 cases with a confirmed or presumptive diagnosis of hepatitis A and 74 cases with a confirmed or presumptive diagnosis of hepatitis E.
The sensitivity and specificity of the IgM capture assay kit were 97% and 100%, respectively, and the corresponding values for the other kit were 70% and 78%, respectively.
The IgM capture assay kit has higher sensitivity and specificity in diagnosing acute enteric viral hepatitis E.
Biomedical and Environmental Sciences 01/2008; 20(6):512-5. · 1.15 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: HEV is classified into H (human) group and Z (zoonosis) group according to its compatible host. H group contains genotype 1 and genotype 2 HEV isolates which infect human only; Z group contains genotype 3 and genotype 4 HEV isolates which infect both human and animals. After analysis of amino acid sequences between ORF2 aa368 and aa606, four group-conserved sites that were all located in the neutralization region of ORF2 were identified. They are aa483, aa492, aa497 and aa599. Mutation analysis and capture PCR were then performed on these sites with a group of monoclonal antibodies. Results showed that the difference of the aa497 between H and Z groups was responsible for the maintenance of their group-specific immunodominant epitopes, probably through confirmation-dependent epitope changes. Thus, aa497 and its related change on the surface structure of HEV may play important roles in host selection by H and Z groups of HEV.
Bing du xue bao = Chinese journal of virology / [bian ji, Bing du xue bao bian ji wei yuan hui] 12/2007; 23(6):454-8.
[Show abstract][Hide abstract] ABSTRACT: In this study, a new combined enzyme immunoassay(NRAg ELISA) for detection of HBV PreS1 and core antigens which was highly consistent with serum HBV DNA test was established. The serial serum dilution test indicated that the average sensitivity of the assay was 10(3.2) genome copies/mL (95% CI: 10(2.2-4.2) genome copies/mL), which was notably higher than the test performed on Pre S1 or core antigen alone. The test with sera from 994 blood donors whose HBsAg were negative demonstrated that the specificity of this assay was 99.7% (95% CI: 99.1%-99.9%). 271 serum samples from chronic hepatitis patients were also examined and the result showed that the total consistent rate between NRAg ELISA and HBV DNA was 96.3% (95% CI: 93.3%-98.2%). The NRAg ELISA S/CO(signal/cutoff) was closely correlated with HBV genome copies (R = 0.9158, n=231). Furthermore,by using this assay,we found a patient whose HBsAg was negative but HBV DNA was positive. Sequencing result showed that HBV genome from this patient had a point mutation in the "a"epitope of S gene. Our results indicate that HBV NRAg ELISA has a high relativity with HBV DNA test, and can effectively detect the mutation of HBsAg,it is expected to be a potent tool for screening HBsAg mutant and is a convenient method for substituting HBV DNA test.
Bing du xue bao = Chinese journal of virology / [bian ji, Bing du xue bao bian ji wei yuan hui] 08/2007; 23(4):252-7.
[Show abstract][Hide abstract] ABSTRACT: To investigate the incidence of HEV infection in population of non-remunerate blood donors in Shaoxing.
Blood specimens from 3701 non-remunerate blood donors were collected, ELISA were used to study anti-HEV IgG and IgM antibodies, RT-PCR were further used to study HEV RNA in samples from donors whose anti-HEV IgM was positive.
Anti-HEV IgG positive rate was 29.19% (1107/3701), anti-HEV IgM positive rate was 1.35% (50/3701) among non-remunerate blood donors in Shaoxin. Six cases were positive for HEV RNA. The positive rate was 0.16% (6/3701), and all the 6 cases belonged to HEV genotype 1. Different seasons showed no interference on the positive rate of IgG and IgM.
The detecting and studying of HEV infection among donors was important to ensure the safety of blood products and blood transfusion.
Zhonghua shi yan he lin chuang bing du xue za zhi = Zhonghua shiyan he linchuang bingduxue zazhi = Chinese journal of experimental and clinical virology 04/2007; 21(1):29-31.
[Show abstract][Hide abstract] ABSTRACT: Genotype 4 hepatitis E virus (HEV) is the dominant cause of hepatitis E in the People's Republic of China; swine are the principal reservoir. Our study was conducted in 8 rural communities of southern China, where families keep pigs near their homes. Phylogenetic analysis showed that 23 of 24 concurrent virus isolates from this region are genotype 4 strains. Among the study populations, immunoglobulin G anti-HEV seroprevalence accumulated with age at approximately equal to 1% per year for persons < or =60 years of age. After age 30 years, seroprevalence increased at higher rates for male than for female study participants. The overall seroprevalence was 43% (range 25%-66%) among the communities. Infection rates were higher for participants between 25 and 29 years of age. The results suggest that HEV infection probably has been endemic in southern China for at least 60 years, with swine being the principal reservoir of human HEV infection in recent years.
[Show abstract][Hide abstract] ABSTRACT: To evaluate the serological markers and biological marker in the diagnosis of hepatitis E infection in a rhesus monkey model.
86 rhesus monkeys had been infected with different doses of HEV. Hence, they were taken sequential blood samples at intervals up to 86 weeks for 4 hepatitis E virus (HEV) specific antibody assays (E2-IgM, E2-IgG, GL-IgG, and YES-IgG), and nucleic acid assay.
All the animals produced E2-IgG and all but one also produced E2-IgM and excreted the virus in stool, whereas positive rate of GL-IgG and YES IgG were low and correlated with virus level. Hepatitis occurred over a period of 4 weeks (between 3 an 7 weeks) after infection. Virological marker occurred mainly during incubation period and declined rapidly after onset of hepatitis. Seroconversion of E2-IgM occurred before onset of hepatitis in 70% monkeys and declined rapidly up to 50% of peak value after 4 weeks. E2-IgM seroconversion was closely paralleled by E2-IgG; however, E2-IgG persisted in all animals for the entire duration of experiment of up to 86 weeks. Production of GL-IgG and YES-IgG was delayed by one week after the E2 antibodies, these antibodies showed a transient occurrence and seroprevalence declined to 50% of the peak value over a period of 12 weeks.
E2-IgM might be used as a suitable acute hepatitis E marker, and E2-IgG as a suitable epidemiological marker. The seroconversion or titer elevation of GL-IgG and YES-IgG antibodies probably used to confirm the infection. The viral markers are optional for early diagnosis.
Zhonghua gan zang bing za zhi = Zhonghua ganzangbing zazhi = Chinese journal of hepatology 02/2004; 12(1):7-10.
[Show abstract][Hide abstract] ABSTRACT: To understand the infectivity and pathogenicity of the plasma of hepatitis E virus (HEV) viremia to primate animals.
RNA fragment of HEV genotype IV was detected on one healthy donor who was positive for anti-HEV IgM and negative for anti-HEV IgG. Then 10 ml plasma from above donor was transfused to rhesus monkey to observe its infectivity and pathogenicity.
Acute hepatitis E was developed in rhesus monkey who accept HEV RNA positive plasma. It was confirmed by virological, immunological, biochemical and histopathological data.
Acute hepatitis E can be induced by plasma transfusion of HEV viremia, which indicate the possibility of transfusion transmitted hepatitis E
Zhonghua gan zang bing za zhi = Zhonghua ganzangbing zazhi = Chinese journal of hepatology 02/2004; 12(1):13-5.
[Show abstract][Hide abstract] ABSTRACT: To evaluate the reliability of different hepatitis E diagnosis reagent tests on the acute hepatitis E.
Three acute hepatitis E diagnosis tests, E2-IgM (Wantai, China), GL-IgM and GL-IgG (Genelabs, Singapore) were compared for their reliability in a sera panel composed by 273 healthy individuals and 525 hepatitis.
The specificity of E2-IgM on the diagnosis of acute hepatitis E was 100.0%, it was significantly higher than GL-IgM (96.7%) and GL-IgG (85.4%). The sensitivity of E2-IgM and GL-IgG were 97.9% and 93.8% respectively, both significantly higher than GL-IgM (72.9%). Among 65 acute hepatitis cases being positive on GL-IgM test but negative on E2-IgM, 58 (89.2%) cases were found to be positive with anti-hepatitis A virus IgM, it indicated that the GL-IgM test might be interfered by other IgM antibodies on serum.
E2-IgM is a good test for the diagnosis of acute hepatitis E.
Zhonghua gan zang bing za zhi = Zhonghua ganzangbing zazhi = Chinese journal of hepatology 02/2004; 12(1):16-7.
[Show abstract][Hide abstract] ABSTRACT: To look into the serological characteristics of a hepatitis E outbreak.
Sera from the first five patients with acute icteric hepatitis who developed the disease successively within ten days and the 1,675 employees routinely having their lunch in a dining hall of a department (outbreak population) were examined for anti.HEV IgM and IgG at 26th days after the outbreak, and the 883 employees of a neighboring department not having their lunch in the hall were selected as control (control population).
The five patients were all positive for anti-HEV IgM and IgG. The positive rates of anti-HEV IgM and IgG in outbreak population were 8.7% and 38.4% respectively, both significantly higher than those in control population which were only 0.1% and 28.6%. The numbers with abnormal ALT in the 145 individuals with anti-HEV IgM(+) of outbreak population were significantly higher than those in the IgM(-) individuals of the same group as well as in control, while the abnormal ALT ratio in the IgM(-) individuals of the outbreak was not higher than that in control. The results from the four patients' serial sera showed that the anti-HEV IgM titers declined gradually and were undetectable at about 4th month after infection, and the IgG titers increased to peak in about 2-3 months after infection, then declined very slowly. The mean IgG titer of the anti-HEV IgM(+) individuals was significantly higher than that of the IgM(-) but IgG(+) individuals in outbreak population, and the latter was significantly higher than the IgG(+) individuals in control, which suggested that the post-infection individuals' immunities to HEV were boosted during the outbreak. There was no difference between sex or age groups for the anti-HEV IgM(+) ratio, but the abnormal ALT was much more frequent in the anti-HEV IgM(+) male than in the female, and no difference was observed between age groups.
The pathogen of the outbreak of acute icteric hepatitis was hepatitis E virus and associated with food intake. Anti-HEV IgM and IgG were used not only for diagnosis of hepatitis E but also for surveilance in mass population. The attack risk was not associated with age or sex, but the abnormal ALT was much more frequent fresh infectors in male.
Zhonghua shi yan he lin chuang bing du xue za zhi = Zhonghua shiyan he linchuang bingduxue zazhi = Chinese journal of experimental and clinical virology 01/2004; 17(4):361-4.