Antigenic domains of the open reading frame 2-encoded protein of hepatitis E virus.
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The antigenic composition of the hepatitis E virus (HEV) protein encoded by open reading frame 2 (ORF2) was determined by using synthetic peptides. Three sets of overlapping 18-, 25-, and 30-mer peptides, with each set spanning the entire ORF2 protein of the HEV Burma strain, were synthesized. All synthetic peptides were tested by enzyme immunoassay against a panel of 32 anti-HEV-positive serum specimens obtained from acutely HEV-infected persons. Six antigenic domains within the ORF2 protein were identified. Domains 1 and 6 located at the N and C termini of the ORF2 protein, respectively, contain strong immunoglobulin G (IgG) and IgM antigenic epitopes that can be efficiently modeled with peptides of different sizes. In contrast, antigenic epitopes identified within the two central domains (3 and 4) were modeled more efficiently with 30-mer peptides than with either 18- or 25-mers. Domain 2 located at amino acids (aa) 143 to 222 was modeled best with 25-mer peptides. A few 30-mer synthetic peptides derived from domain 5 identified at aa 490 to 579 demonstrated strong IgM antigenic reactivity. Several 30-mer synthetic peptides derived from domains 1, 4, and 6 immunoreacted with IgG or IgM with more than 70% of anti-HEV-positive serum specimens. Thus, the results of this study demonstrate the existence of six diagnostically relevant antigenic domains within the HEV ORF2 protein. (+info)
Effect of ursodeoxycholic acid administration in patients with acute viral hepatitis: a pilot study.
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BACKGROUND: Ursodeoxycholic acid (UDCA) is able to improve biochemical markers of cholestasis, with a parallel decrease in transaminases, in various cholestatic liver diseases. AIM: To evaluate the effects of UDCA administration on acute viral hepatitis-related cholestasis and the course of acute viral hepatitis. METHODS: Seventy-nine consecutive patients with acute viral hepatitis (HBV: 43, HCV: 11, HAV: 15, HEV: 3, Non A-E: 7) were randomized to receive either UDCA for 3 weeks or no treatment. Liver biochemistry and serum bile acid determinations were run at weekly intervals. RESULTS: No significant differences were observed in mean percentage decreases in transaminases between treated and untreated patients. By contrast, cholestatic indexes decreased significantly more quickly in patients treated with UDCA than in controls, and this effect was more evident in patients with increasing alanine transaminase levels at admission. After a peak at the end of the first week of therapy, serum levels of conjugated ursodeoxycholic acid (CUDCA) showed a gradual decrease. Conjugated cholic acid (CCA) and chenodeoxycholic acid (CCDCA) showed a progressive decrease with the resolution of viral hepatitis, but no influence of UDCA administration was observed. CONCLUSIONS: Our study demonstrates that UDCA significantly improves cholestatic indices in patients with acute viral hepatitis, but this effect does not seem to affect the course of the illness. (+info)
GBV-C/HGV-RNA in serum and peripheral blood mononuclear cells in hemodialysis patients.
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BACKGROUND: Hemodialysis patients are at high risk of hepatitis B, C, and G virus infection. The prevalence of GBV-C/HGV-RNA was analyzed in serum and peripheral blood mononuclear cells (PBMCs) from 52 hemodialysis patients. METHODS: GBV-C/HGV-RNA detection was performed by reverse transcription-polymerase chain reaction (RT-PCR) with primers of 5'-noncoding (5'-NC) and NS3 regions of the GBV-C/HGV genome. To increase sensitivity, serum samples were ultracentrifuged prior to the RT-PCR to concentrate the viral particles. The amplified products from 20 serum and 5 peripheral blood mononuclear cells (PBMC) samples were sequenced. RESULTS: GBV-C/HGV-RNA was detected in sera of 9 (17%) and in PBMCs of 30 (58%) patients. After serum ultracentrifugation, GBV-C/HGV-RNA was positive in 20 (95%) of the patients, with GBV-C/HGV-RNA only in PBMCs. Thus, GBV-C/HGV-RNA was detected in serum and PBMCs from 29 (56%) patients, four of whom had antibodies against GBV-C/HGV E2 protein (anti-HGE2); one patient (2%) had GBV-C/HGV-RNA only in PBMCs, but was anti-HGE2 positive. Seven (32%) patients who did not have GBV-C/HGV-RNA were anti-HGE2 positive. The nucleotide sequence homology between serum samples from the patients who were GBV-C/HGV-RNA positive after ultracentrifugation, and paired serum and PBMCs from five of them, ranged from 90 to 96% and from 92 to 98%, respectively. CONCLUSIONS: We found a high prevalence of GBV-C/HGV-RNA in serum and PBMC samples from hemodialysis patients. Whether or not this finding can be extended to other populations requires further study. (+info)
Hepatitis A incidence rate estimates from a pilot seroprevalence survey in Rio de Janeiro, Brazil.
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BACKGROUND: To assess the impact of water sanitation and sewage disposal, part of a major environmental control programme in Rio de Janeiro, we carried out sero-prevalence studies for Hepatitis A virus (HAV) in three micro-regions in Rio de Janeiro. Each region varied with regard to level of sanitation. We are interested in assessing the discriminating power of age-specific prevalence curves for HAV as a proxy for improvement in sanitation. These curves will serve as baseline information to future planned surveys as the sanitation programme progresses. METHODS: Incidence rate curves from prevalence data are estimated parametrically via a Weibull-like survival function, and non-parametrically via maximum likelihood and monotonic splines. Sera collected from children and adults in the three areas are used to detect antibodies against HAV through ELISA. RESULTS: We compare baseline incidence curves at the three sites estimated by the three methods. We observe a strong negative correlation between level of sanitation and incidence rates for HAV infection. Incidence estimates yielded by the parametric and non-parametric approaches tend to agree at early ages in the microregion showing the best level of sanitation and to increasingly disagree in the other two. CONCLUSION: Our results support the choice of HAV as a sentinel disease that is associated with level of sanitation. We also introduce monotonic splines as a novel non-parametric approach to estimate incidence from prevalence data. This approach outperforms current estimating procedures. (+info)
Lack of evidence for increased risk of hepatitis A infection in homosexual men.
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In 1997, prevalence of and risk factors for hepatitis A virus (HAV) infection were evaluated in 146 homosexual and 286 heterosexual men attending a Sexually Transmitted Disease (STD) Clinic in Rome, Italy. Total HAV antibody (anti-HAV) was detected in 60.3% of homosexuals and 62.2% of heterosexuals. After adjustment for the confounding effects of age, years of schooling, number of sexual partners, use of condoms, and history of STD, homosexuals were not found to be at increased risk of previous HAV exposure than heterosexuals (OR 1.1; 95% CI 0.7-1.9). Independent predictors of the likelihood of anti-HAV seropositivity among homosexuals and heterosexuals were: age older than 35 years and positive syphilis serology which is likely a proxy of lifestyles that increase the risk of faecal-oral infections. These findings do not support a higher risk in homosexual men but could suggest a role for the vaccination of susceptible patients attending STD clinics. (+info)
Prevalence of antibodies against hepatitis A and E viruses among rural populations of the Chaco region, south-eastern Bolivia.
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We conducted a cross-sectional study to determine the seroprevalence of antibodies against hepatitis A and hepatitis E viruses (HAV and HEV) in the population of two rural areas, Camiri and Villa Montes, of the Chaco region, south-eastern Bolivia. HAV antibodies were detected in 461 (94.1%) of 490 serum samples tested, not differing significantly between sexes and study areas. The HAV seropositivity rate (64.7%) was high even in the youngest age group (1-5 years). The prevalence of HEV was 7.3%, with no significant differences between sexes. The prevalence of HEV antibodies in the population of the Camiri area (10.4%) was significantly higher than in the Villa Montes area (4.4%), possibly due to the better quality of drinking water in the Villa Montes area. In the population /= 31 year-old group. This is consistent with findings in other countries. This is the first report of the prevalence of HEV infection in Bolivia. (+info)
Immunogenicity and safety of hepatitis A vaccine in liver and renal transplant recipients.
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Organ transplant recipients with chronic hepatitis B or hepatitis C virus infection may be at increased risk of fulminant hepatitis A. Liver transplant (LTX) recipients, renal transplant (RTX) recipients, and healthy controls received 2 doses of hepatitis A vaccine 6 months apart. Anti-hepatitis A virus (anti-HAV) seroconversion after the primary dose occurred in 41% of the LTX patients, 24% of the RTX patients, and 90% of the controls. After the booster dose, the respective rates were 97%, 72%, and 100% (P<.001). RTX patients also had significantly lower geometric mean titers (GMTs) of anti-HAV than LTX patients and controls. In the RTX group, the seroconversion rate and GMT were inversely associated with the number of immunosuppressive drugs received by the patients. The vaccine was well tolerated. Hepatitis A vaccine can be recommended to LTX and RTX patients, but the patients should receive a full course of 2 doses before imminent exposure. (+info)
Identity of a novel swine hepatitis E virus in Taiwan forming a monophyletic group with Taiwan isolates of human hepatitis E virus.
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Recently, we found that more than 10% of the cases of acute non-A, non-B, non-C hepatitis in Taiwan were caused by a novel strain of hepatitis E virus (HEV). Since none of these patients had a history of travel to areas where HEV is endemic, the source of transmission remains unclear. The recent discovery of a swine HEV in herd pigs in the United States has led us to speculate that HEV may also circulate in herd pigs in Taiwan and may serve as a reservoir for HEV in Taiwan. Of 275 herd pigs obtained from 10 pig farms in Taiwan, 102 (37%) were seropositive for serum anti-HEV immunoglobulin G (IgG). A 185-bp genomic sequence within the ORF-2 of the HEV genome was amplified and cloned from serum samples of an anti-HEV positive pig and subsequently from serum samples of a patient with acute hepatitis E. Sequence comparison revealed that the swine and human isolates of HEV share 97.3% identity. Phylogenetic analyses further showed that the Taiwan swine and human isolates of HEV form a distinct branch divergent from all other known strains of HEV, including the U.S. swine strain. To examine the potential risk of cross-species transmission of swine HEV to humans, the seroprevalences of anti-HEV IgG in 30 swine handlers, 20 pork dealers, and 50 control subjects were assessed and were found to be 26.7, 15, and 8%, respectively (for swine handlers versus controls, P = 0.048). Our findings may help provide an understanding of the modes of HEV transmission and may also raise potential public health concerns for HEV zoonosis. (+info)