Prevalence of Hepatitis E Virus and Its Associated Outcomes among Pregnant Women in China.

Hepatitis E virus (HEV) is a significant public health concern worldwide. Pregnant women are at high risk of severe HEV infection. Various adverse outcomes in pregnant women related to HEV infection have been well documented in low-income and middle-income countries with poor sanitation. However, previous studies have provided inconsistent conclusions regarding the effects of HEV infection on the health of pregnant women and their infants in developed countries and contemporary China. In China, previous studies on HEV in pregnant women mainly focused on anti-HEV IgM and/or anti-HEV IgG. In this study, 4244 pregnant women were retrospectively analyzed for HEV-related markers. The positive rates of HEV antigen, HEV RNA, anti-HEV IgM, and anti-HEV IgG were 0.28%, 0.54%, 0.35%, and 10.49%, respectively. Among the 467 pregnant women who tested positive for at least one HEV-related marker, 92.93% (434) were positive for anti-HEV IgG only and 0.21% (1) were positive for HEV antigen, anti-HEV IgM, and anti-HEV IgG. Although the prevalence of anti-HEV IgG significantly increased with age, the prevalence of anti-HEV IgM, HEV RNA, and HEV antigen did not differ among pregnant women of different ages. Thirty-three pregnant women were positive for at least one of anti-HEV IgM, HEV antigen, and HEV RNA, and these individuals were recently or currently infected with HEV. None of the 33 pregnant women exhibited obvious clinical symptoms. Of the 33 pregnant women, 39.39% (13) experienced adverse fetal outcomes, including preterm birth, fetal distress, and low birth weight, the incidence of which was significantly higher than in pregnant women who were not recently or currently infected with HEV. These findings suggest that maternal HEV infection may impact the health of fetuses; thus, these results may contribute to the development of appropriate public health interventions for this population.

Placenta as a site of HEV replication and inflammatory cytokines modulating the immunopathogenesis of HEV in pregnant women.

Viral hepatitis E is an under-estimated clinical entity with high mortality (20%-30%), especially in the third trimester of pregnancy. As complications due to hepatitis E virus (HEV) in pregnancy is much greater, it is hypothesized that HEV may cross the placenta and replicate in placental tissues even weeks after clearance from the blood, and cytokines may play a role in the immunopathogenesis of HEV in pregnancy. A total of 12 pregnant women with features of acute viral hepatitis/acute liver failure and positive for either HEV-immunoglobulin M (IgM)/HEV-RNA and 30 pregnant women negative for HEV RNA/IgM/immunoglobulin G were enrolled as study subjects and healthy controls, respectively. Following delivery, 5 ml blood was collected from the mother for HEV-RNA. Replicative RNA and viral load in placental tissue were detected through Real-Time PCR. Placental tissues from the maternal/fetal sides were stained for HEV antigen using HEV-open reading frame-2 antibody by immunohistochemistry (IHC) and for histopathological changes by haematoxylin and eosin. Plasma samples were tested for interleukin (IL)-1ß and IL-18 cytokine levels using Duo-R&D ELISA kit, whereas peripheral blood mononuclear cells were used to study the inflammasomes and IL-1ß and IL-18 cytokine genes expression.Of the 10 HEV RNA-positive sera, 9 had HEV RNA either in the maternal/fetal side of the placenta with the mean viral load of 137.4 IU/ml. Of the 10 HEV RNA-positive pregnant women, stillbirth in two and fetal and maternal death in one case was reported. IHC revealed strong brownish cytoplasmic staining (HEV antigen) in cytotrophoblasts and syncytiotrophoblast cells in positive samples. The maternal/fetal side of the infected placenta showed irregular intervillous fibrin deposition as well as tissue necrosis. The mean levels of IL-1ß and IL-18 cytokines in serum of infected subjects were significantly higher than the healthy controls (17.31 ± 4.462 vs. 8.85 ± 4.36 pg/ml; p < 0.0001*** and 2275 ± 536.9 vs. 1085 ± 531.7 pg/ml; p < 0.0001***), respectively. Detecting replicative HEV RNA and HEV antigen in placental tissues indicated the extra-hepatic replication of HEV. Furthermore, placental tissue necrosis and significant rise of cytokine levels in HEV-infected pregnant women might be contributing to the HEV pathogenesis in pregnancy.

Prevalence of Hepatitis E Virus Infection among Laboratory Rabbits in China.

Hepatitis E virus (HEV) is zoonotic and the leading cause of acute viral hepatitis worldwide. Rabbit HEV can infect humans and is prevalent globally. It is reported that laboratory rabbits are also naturally infected with HEV. Therefore, it is important to investigate in a large scale the prevalence of HEV in laboratory rabbits. Serum samples were collected from 649 laboratory rabbits of 13 different commercial vendors in Beijing, China, from 2017 to 2019, and anti-HEV and HEV antigen (Ag) were tested. Fecal samples were collected from 50 laboratory rabbits from one of the vendors for HEV RNA detection. Six laboratory rabbits with natural HEV infection were euthanized and their liver, kidney, bile and urine samples were collected for HEV RNA quantification. Liver tissues were subjected to histopathology analysis. The overall positive rates of anti-HEV antibodies and HEV-Ag are 2.6% (15/588) and 7.9% (51/649), respectively. HEV RNA was detected in 12.0% (6/50) of the rabbits. High viral load of HEV RNA was detected in liver and bile samples. Liver inflammation was observed. HEV is circulating in laboratory rabbit population in China. Strict screening is crucial to ensure experimental accuracy and prevent zoonotic transmission to research personnel.

Evaluation of hepatitis E antigen kinetics and its diagnostic utility for prediction of the outcomes of hepatitis E virus genotype 1 infection.

HEV-Ag ELISA assay is a reliable diagnostic test in resource-limited areas. HEV genotype 1 (HEV-1) infections are either self-limited or progress to fulminant hepatic failure (FHF) and death if anti-HEV therapy is delayed. Limited data is available about the diagnostic utility of HEV Ag on HEV-1 infections. Herein wWe aimed to study the kinetics of HEV Ag during HEV-1 infections at different stages, i.e., acute HEV infection, recovery, and progression to FHF. Also, we evaluated the diagnostic utility of this marker to predict the outcomes of HEV-1 infections. Plasma of acute hepatitis E (AHE) patients were assessed for HEV RNA by RT-qPCR, HEV Ag, and anti-HEV IgM by ELISA. The kinetics of HEV Ag was monitored at different time points; acute phase of infection, recovery, FHF stage, and post-recovery. Our results showed that the level of HEV Ag was elevated in AHE patients with a significantly higher level in FHF patients than recovered patients. We identified a plasma HEV Ag threshold that can differentiate between self-limiting infection and FHF progression with 100% sensitivity and 88.89% specificity. HEV Ag and HEV RNA have similar kinetics during the acute phase and self-limiting infection. In the FHF stage, HEV Ag and anti-HEV IgM have similar patterns of kinetics which could be the cause of liver damage. In conclusion, the HEV Ag assay can be used as a biomarker for predicting the consequences of HEV-1 infections which could be diagnostically useful for taking the appropriate measures to reduce the complications, especially for high-risk groups.

A possible risk of environmental exposure to HEV in Ibadan, Oyo State, Nigeria.

Hepatitis E virus (HEV) infection is both a major public health concern and emerging global health concern, with a documented incidence of 20 million, 3.4 million clinical cases, 70,000 deaths, and 3,000 stillbirths. The aetiologic agent, HEV is a primarily enterally transmitted hepatotropic virus. Fecal samples were collected from three selected pig farms across Ibadan, South-west Nigeria. Randomly picked samples were pooled per unit pen and fecal suspensions prepared were subjected to HEV Antigen (Ag) enzyme-linked immunosorbent assay. Molecular probing was done by Reverse Transcription and nested polymerase reaction (RT-nPCR) and deep sequencing. Sequencing was done paired-end for 300 cycles using the HiSeq system. Overall farm prevalence of 66.7% (2/3) and prevalence at individual level of 13.2% (9/68) were recorded. All nine samples positive for the ELISA screen were negative when subjected to RT-nPCR assays. Further, on deep sequencing, no HEV genomic fragment was found in the sample using de-novo assembly. Findings suggest possibly inapparent HEV in the pigs studied or a yet to be identified protein with HEV-Ag cross-reactivity ability on ELISA, thus constituting a possible risk of exposure to HEV infection in the population. Consequently, we recommend prompt intervention to unravel the mystery and break the chain of transmission.

Unexpected long-lasting anti-HEV IgM positivity: Is HEV antigen a better serological marker for hepatitis E infection diagnosis?

Hepatitis E virus (HEV) is the leading cause of acute hepatitis worldwide. The minimum criterion for diagnosis of acute infection is detection of anti-HEV antibodies, although there are scant data on IgM duration. Our aim was to assess the persistence of HEV markers after acute self-limited hepatitis E. HEV serological tests (IgM by Mikrogen and Wantai and HEV-Ag) and HEV RNA were carried out in two cohorts: (a) patients with prior acute hepatitis E (ALT >10 x ULN plus positive IgM ± HEV RNA) currently self-limited and (b) 50 blood donors with positive HEV RNA. Among 25 cases of prior acute hepatitis E, after a median follow-up of 34 months, all presented undetectable HEV RNA. However, anti-HEV IgM remained detectable in 14 (56%) by Mikrogen, 6 (24%) by Wantai and none for HEV-Ag. Anti-HEV IgM tested positive in 80%-100% within the second year and 17%-42% over 3 years later, by Wantai and Mikrogen, respectively. Among HEV RNA-positive donors, 12 (25%) tested positive for either IgM by Mikrogen or Wantai, 9 (18%) for both and 18 (36%) for HEV-Ag. HEV-Ag positivity was more likely as HEV RNA was higher (14% if <2.2 log IU/mL; 64% if RNA ≥ 3.7). Overall, HEV-Ag performed best, with a positive predictive value of 100% and diagnostic accuracy of 57%. Anti-HEV IgM exhibited unexpectedly long persistence after a self-limited acute hepatitis E. HEV-Ag had the best performance and could be especially useful in settings where HEV RNA is not available.

Four-year long (2014-2017) clinical and laboratory surveillance of hepatitis E virus infections using combined antibody, molecular, antigen and avidity detection methods: Increasing incidence and chronic HEV case in Hungary.

BACKGROUND: Hepatitis E virus (HEV) is a pathogen of viral hepatitis. Since 2006, the number of reported HEV cases has ten-fold increase in Hungary. OBJECTIVES: The aim of this clinical and laboratory surveillance study was to analyse and confirm HEV IgM-positive sera with different methods in four consecutive years (2014-2017) in Hungary. STUDY DESIGN: Between 2014 and 2017, a total of 1439 sera samples were tested for HEV from in/out-patients with unknown hepatitis from university and county hospitals and general practitioners from three counties in Southwest Hungary (covered population: Σ894.000 persons) using combined antibody (serology), various molecular (RT-PCR and RT-qPCR), novel antigen (Ag) and avidity detection methods. RESULTS: Total of 162 (11.3%) of the 1439 sera were HEV IgM-positive including 13 (8%) HEV RT-PCR-positive (confirmed as HEV genotype 3 sub-genotypes 3a/c/e/f/i in genus Orthohepevirus A) with up to 1.1383 × 108 RNA copy/ml, 30 (18.5%) HEV Ag-positive and 16 with low avidity index for HEV, respectively. Total of 6 samples were positive simultaneously with the combined four methods and 31 with three methods. If the quotient of serum sample's OD/cut-off of anti-HEV ELISA IgM and IgG scores is higher than ≥1 it predisposes for acute HEV infection. No rat or ferret HEV RNA (genus Orthohepevirus C) were identified from these specimens by RT-PCR. During our surveillance period a 68-year-old professional (meat-packing) hunter with kidney transplantation and immunosuppressive therapy was confirmed and treated as the first documented case of chronic HEV infection in Hungary. CONCLUSION: This four-year-long clinical and laboratory surveillance highlights the increasing importance of acute and chronic HEV infections in Hungary and supports the use of confirmatory assays for laboratory diagnosis of HEV in human.

Evaluation of an antigen assay for diagnosing acute and chronic hepatitis E genotype 4 infection.

BACKGROUND AND AIM: Results obtained from different hepatitis E virus (HEV) tests are usually inconsistent. The detection of serum HEV antigen (Ag) has been suggested to be more sensitive for the diagnosis of genotypes 1 and 3 HEV. METHODS: We compared the diagnostic accuracies of serum HEV Ag and HEV RNA by using 202 serum samples from patients suspected acute viral hepatitis. RESULTS: The HEV Ag assay was 100% specific. The lower detected levels of viremia ranged from 102 to 103  copies/mL. The sensitivity of the HEV Ag test was 90.5%. One of the 42 cases was negative for anti-HEV IgM, but HEV Ag was still detectable. The detectable period of HEV Ag was in concordance with the detectable period of HEV RNA. Serum HEV Ag was persistently detected in two cases of chronic hepatitis E, confirmed by the persistent presence of HEV RNA despite being negative for anti-HEV IgM. HEV Ag demonstrated good consistency with positive HEV RNA (k = 0.938, P < 0.001). Receiver operating characteristic analysis of HEV Ag suggested a second cut-off value of >0.095 to predict HEV patients with 95.24% sensitivity and 98.75% specificity, and the area under the curve was 0.9887, which was higher than that of three commercial anti-HEV IgM ELISA tests. CONCLUSIONS: The presence of HEV Ag has good consistency with HEV RNA in both acute and chronic genotype 4 hepatitis E. HEV Ag is a more promising serum marker to identify active genotype 4 HEV infection than anti-HEV IgM and HEV RNA.

Hepatitis E virus ORF 1 induces proliferative and functional T-cell responses in patients with ongoing and resolved hepatitis E.

BACKGROUND AND AIMS: Hepatitis E virus (HEV) is a major cause of acute viral hepatitis with >3 million symptomatic cases per year accounting for 70 000 HEV-related deaths. HEV-specific T-cell responses have been investigated against structural proteins expressed by open reading frames (ORF) 2 and 3. T-cell responses against non-structural HEV proteins encoded by ORF1 are hardly studied. The aim of this study was to determine HEV ORF1-specific T-cell responses in comparison to ORF2/3 in patients exposed to HEV. METHODS: HEV-specific CD4+ and CD8+ T-cell responses against HEV genotype 3 were investigated in patients with acute and chronic hepatitis E as well as in HEV seropositive and seronegative individuals. HEV-specific T-cell responses were determined by proliferation and intracellular cytokine assay upon stimulation of PBMCs with HEV-specific overlapping peptide pools spanning the entire HEV genome. HEV-antigen was measured using an anti-HEV antigen-specific ELISA. RESULTS: Broad HEV ORF1-specific T-cell responses were detected in patients with acute, resolved and chronic hepatitis E without distinct dominant regions. The magnitude and frequency in recognition of ORF1-specific T-cell responses were similar compared to responses against HEV ORF2/3. Longitudinal studies of HEV-specific T-cell responses displayed similar behaviour against structural and non-structural proteins. HEV-antigen levels were inversely correlated with HEV-specific T-cell responses. CONCLUSIONS: HEV-specific T-cell responses are detectable against the entire HEV genome including the non-structural proteins. HEV-specific T-cell responses are associated with control of HEV infection. These findings have implications for the design of HEV vaccines.

Infectivity of hepatitis E virus in SPF rabbit urine / 中华微生物学和免疫学杂志

Objective@#To investigate the presence of hepatitis E virus (HEV) RNA and HEV antigen (HEV-Ag) and to evaluate the infectivity of HEV in urine through a SPF rabbit model of HEV infection.@*Methods@#Serum, fecal and urine samples collected from SPF rabbits with HEV infection were tested for viral and biochemical markers using real-time RT-PCR and ELISA. Liver and kidney biopsies were performed for observing histopathological changes and immunohistochemical staining. Rabbits were challenged with HEV isolated in urine samples to evaluate the infectivity.@*Results@#Rabbit R1# that was injected with rabbit HEV presented viremia, fecal shedding of HEV, high serum level of HEV-Ag, elevated aspartate transaminase (AST) and alanine transaminase (ALT) and typical symptoms of hepatitis. Urine samples of rabbit R1# continued to be positive for HEV RNA and HEV-Ag. Ratios of HEV-Ag to RNA in urine samples of rabbit R1# were significantly higher than those in serum and feces samples. The parameters quantified in routine urinalysis remained within the normal ranges in rabbit R1#. However, pathological changes and the presence of HEV-Ag were observed in kidney tissues. Furthermore, serum and fecal samples that were collected from one of the two rabbits injected with rabbit R1# urine-derived HEV were HEV positive and the virus strains isolated form feces remained infective to rabbits.@*Conclusion@#HEV infection may result in kidney injury and the urine may pose a risk of transmission. HEV-Ag detection in urine may be valuable for the diagnosis of ongoing HEV infection.

Role of HEV antigen detection in HEV-related acute viral hepatitis and acute liver failure.

Detection of HEV antigen presents as an interesting low cost, novel, and rapid diagnostic technique to ascertain HEV viremia where facilities for reverse transcriptase polymerase chain reaction (RT PCR) are sparse. This study was undertaken to assess the relative efficacy of HEV antigen detection by ELISA with currently available diagnostic tests in patients of HEV-related acute viral hepatitis (AVH) and acute liver failure (ALF). This study included 36 ALF and 64 AVH cases. HEV RNA and HEV viral load were determined by RT PCR and real time PCR, respectively. Evidence of recent HEV infection was detected in 45/64 AVH cases and 22/36 ALF cases. IgM anti-HEV antibody, HEV RNA, and HEV antigen were positive in 34/45 (75.56%), 26/45 (57.77%), and 21/45 (46.66%), in the AVH group, and 16/22 (72.72%), 14/22 (63.63%), 12/22 (54.54%) in ALF group, respectively. The concordance between HEV RNA and HEV antigen was 75.56% (P < 0.01) with κ-coefficient of 0.516 and 75.27% (P = 0.07) with κ-coefficient of 0.441 (P = 0.07) in the AVH and ALF patients, respectively, indicating moderate concordance. It was established that HEV antigen detection can be used as a valuable marker of active viremia and a cheaper surrogate to HEV RT PCR, particularly in window period, pregnant and immunocompromised patients, however, it did not correlate with severity of disease or influence the final outcome of illness in any of the study groups. J. Med. Virol 88:2179-2185, 2016. © 2016 Wiley Periodicals, Inc.

Performance of an antigen assay for diagnosing acute hepatitis E virus genotype 3 infection.

BACKGROUND: Hepatitis E virus (HEV) is a major cause of hepatitis worldwide. Its diagnosis is based on the detection of anti-HEV IgM and/or HEV-RNA. OBJECTIVE: To evaluate the performance of the Wantaï HEV-antigen (Ag) ELISA(Plus) assay for diagnosing acute HEV infections. STUDY DESIGN: Specificity was assessed using 100 blood samples containing no anti-HEV IgM, anti-HEV IgG, or HEV-RNA. Cross reactivity was assessed using samples positive for hepatitis C virus RNA (n=10), Epstein-Barr virus DNA (n=10) and cytomegalovirus DNA (n=10). Serial dilutions of 4 HEV RNA positive samples were used to estimate the corresponding viremia detected with the Ag assay. Blood samples from 33 immunocompetent and 31 immunocompromised patients with an acute HEV genotype 3 infection, HEV-RNA positive, were tested to assess diagnostic sensitivity. RESULTS: The HEV-Ag assay was 100% specific, with no cross-reactivity. The lower viremias detected ranged from 10(3)copies/ml to 10(5)copies/ml (800-80,000UI/ml). Diagnostic sensitivity for an acute HEV infection was 91%, with no significant difference between immunocompetent (88%) and immunocompromised (94%) patients. The HEV-Ag assay was more frequently positive in immunocompromised patients at the acute phase (94%) than was the anti-HEV IgM test (71%; p=0.04). The HEV-Ag assay ratio was correlated with HEV-RNA viral load (ρ=0.54; p<0.0001). CONCLUSION: The HEV-Ag assay performed well and could be suitable for laboratories with no molecular diagnosic facilities.

Investigation of suspected viral hepatitis outbreaks in North West India.

Hepatitis E (HEV) infection is diagnosed on the basis of serum anti-HEV IgM detection. In outbreaks, early diagnostic method is important for prompt control measures. This study compared 3 diagnostic methods in 60 serum samples collected in suspected HEV outbreaks. The suitability of saliva samples for antibody detection was also evaluated in 21 paired serum saliva samples. The anti-HEV IgM, HEV-Ag, and HEV-RNA were detected in serum samples of 52 (86.66%), 16 (26.66%), and 18 (30%) patients, respectively. The concordance between serum and saliva IgM was found to be 76.91%. The positivity of PCR and HEV-Ag detection was 100% within 1 week of illness which declined to 5-10% thereafter. The outbreak was attributed to HEV genotype 1, subtype 1a, and the clinical and environmental strains clustered together. HEV-antigen and RNA were an early diagnostic marker with 96.66% concordance. Saliva samples can be used as an alternative in outbreak setting.

Detection and assessment of infectivity of hepatitis E virus in urine.

BACKGROUND & AIMS: Hepatitis E virus (HEV) is known to be excreted in the stool but there has been no report of its presence in urine. This study investigated the presence of HEV RNA and antigen (HEV-Ag) in urine and its possible transmission. METHODS: Serum and urine samples from patients with chronic or acute HEV infection and HEV infected monkeys were tested for viral and biochemical markers. Liver and kidney biopsies from the infected monkeys were analyzed by histopathology and immunohistochemistry. The infectivity of HEV from urine was assessed by inoculation into monkeys. RESULTS: HEV RNA and HEV-Ag were detected persistently in the urine of a patient with chronic HEV infection. Subsequently, HEV RNA was detected in the urine of three of the eight (37.5%) acute patients, all of whom had detectable HEV-Ag in their urine. HEV RNA and HEV-Ag were also detectable in the urine of HEV infected monkeys. The ratio of HEV-Ag to RNA in the urine of the infected monkeys was significantly higher than in their sera and feces. The parameters of routine urinalysis remained within the normal ranges in the hepatitis E patients and infected monkeys, however, pathological changes and HEV-Ag were observed in the kidneys of the infected monkeys. Furthermore, one of two monkeys became infected with HEV after inoculation with urine from another infected monkey. CONCLUSIONS: HEV infection may result in kidney injury and the urine may pose a risk of transmission. HEV-Ag detection in urine may be valuable for diagnosis of ongoing HEV infection.

Evaluation of an antigen-capture EIA for the diagnosis of hepatitis E virus infection.

An enzyme immunoassay (EIA) has been developed for hepatitis E virus (HEV) antigen (HEV-Ag) detection and marketed in China. This study aimed to evaluate the sensitivity of the assay and assess the value of HEV-Ag detection in the diagnosis of HEV infection in comparison with HEV RNA detection. Using serial dilutions of a genotype 4 HEV strain, significant correlation was found between the EIA (S/CO) and HEV RNA (IU/mL) concentration in the range 10(3.5) to 10(0.5) IU/mL HEV RNA, the Pearson correlation coefficient r approached 0.97. The EIA detection limit was 54.6 IU/mL, compared to 24 IU/mL for HEV RNA using real-time RT-PCR. In clinical samples from hepatitis E patients, the HEV-Ag and HEV RNA positivity rates were 55.6% (65/117) and 60.7% (71/117) in sera and 76.7% (56/73) and 84.9% (62/73) in stools, and the concordance of these two markers was 77.8% in sera and 80.8% in stools. In serum samples, the HEV-Ag positivity rate and the concordance between HEV-Ag and HEV RNA were inversely proportional to the presence of anti-HEV antibody. The presence of anti-HEV IgG could reduce the S/CO of the HEV-Ag EIA. These results reveal a significant correlation between the detection of HEV-Ag and HEV RNA. The sensitivity of the HEV-Ag EIA was lower than real-time RT-PCR but could be higher than conventional nested RT-PCR. Therefore, the detection of HEV-Ag in serum and faeces is valuable for the diagnosis and prognosis of HEV infection in developing regions where real-time RT-PCR is not available.

Role of hepatitis E virus antigen in confirming active viral replication in patients with acute viral hepatitis E infection.

BACKGROUND: Demonstration of active viral replication is important in serologically confirmed cases of hepatitis E virus (HEV) infection to assess prognosis. Detection of HEV RNA by reverse transcriptase polymerase chain reaction (rtPCR) is the gold standard for demonstration of active viremia. OBJECTIVES: The present study was designed to compare the diagnostic utility of HEV antigen (Ag) with HEV IgM and HEV rtPCR in detecting the active viral replication. STUDY DESIGN: Blood samples from 156 probable cases of acute viral hepatitis (AVH) were collected. Screening for hepatitis B surface antigen (HBsAg), antibody to hepatitis C virus (anti HCV), IgM antibody to hepatitis A virus (HAV IgM) was done on the Architect platform (Abbott Laboratories, IL, USA). HEV IgM ELISA (Wantai Biological, Beijing, China), HEV-Ag ELISA (Wantai Biological, Beijing, China) and HEV rtPCR were done on all the samples. RESULTS: Out of 156 AVH cases in 56 (35.8%) a diagnosis of HEV was confirmed. Positivity being; anti-HEV IgM 44/56, HEV RNA 20/56, and HEV antigen 17/56 in established cases. Male to female ratio was 3:1. The median age was 40 (range 14-71) years. HEV Ag showed a good concordance with HEV RNA (k=0.635, p<0.001). However HEV IgM did not show any concordance with HEV RNA (k=0.14). CONCLUSION: HEV antigen assay can be used as an additional diagnostic marker to confirm active viral replication in serologically positive samples.