Diagnosis of acute hepatitis E by antibody and molecular testing: a study on 277 suspected cases

Role of real-time polymerase chain reaction in diagnosing Hepatitis E, the commonest cause of acute hepatitis in adult patients seeking institutional care

Background

This cross-sectional study was performed with the aim of determining the prevalence of hepatitis E virus (HEV) infection among acute hepatitis patients attending a tertiary care teaching hospital in a developing country and to determine the relative performance of prevalent diagnostic assays in establishing its diagnosis.

Materials and Methods

A total of 46 adult patients were included in this study, all of whom presented with jaundice of <4 weeks' duration and elevation of AST and ALT above 500 U/L. The prevalence of HEV among patients with acute hepatitis was calculated on the basis of the proportion of recruited patients reacting positively in serum anti-HEV immunoglobulin M (IgM) and real-time polymerase chain reaction (RT-PCR) assays.

Results

Among the recruited patients, 11 (23.91%) and 15 (32.6%) patients were positive for anti-HEV IgM and RT-PCR, respectively. The two tests demonstrated poor inter-test agreement, thereby implying the necessity of performing both tests for reliable diagnosis of acute HEV virus infection. We also observed a significant difference in the duration of illness between RT-PCR positive and negative patients (P = 0.008). The mean (±SD) duration of illness in the two groups was 8.6 (±3.50) and 11.66 (± 5.15) days, respectively. Combining the results of IgM ELISA and RT-PCR, we observed that 23 out of 46 patients (50%) had evidence of acute HEV virus infection among our patients.

Conclusion

Our study suggests that HEV is the commonest cause of acute hepatitis in adult patients attending a tertiary care teaching hospital and that the diagnostic algorithm for its confirmation should include both IgM ELISA and RT-PCR assays.

Role of formalin fixed paraffin embedded liver tissues in the diagnosis of viral hepatitis E in patients with undiagnosed acute liver failure

Viral hepatitis E is gaining importance as an emerging worldwide disease. Though viral hepatitis E (HEV) has been attributed as an etiology of acute liver failure (ALF), however its actual incidence and the immunopathogenesis are being under explored. The present study is aimed at detecting HEV in post mortem liver tissues of patients with undiagnosed ALF. Twenty six liver tissues of ALF patients died of unknown etiology are subjected to nested reverse transcriptase PCR with HEV ORF1 gene targeted primers and HEV RNA is detected in 30.4% (7/23) of ALF cases. Out of seven HEV RNA positive cases, three (42.8%) had HEV antigen positivity by immunohistochemistry on liver tissues using HEV ORF2 antibody. Histopathological examination by H&E staining shows multiacinar confluent hepatic necrosis, bile ductular proliferation, bridging hepatic and periportal necrosis in 4, 4, 2 and 1 cases respectively. The isolates were sequenced using RdRp gene specific primers and found to HEV genotype-1. Quantitative TaqMan real time PCR estimated the viral load ranged between 7.77 × 10³ and 1.44 × 10⁷ viral copies/µl. HEV has been associated with 30.4% (7/23) of undiagnosed ALF cases. Immuno-histochemistry along with molecular testing in FFPE biopsies might be useful for the detection of HEV in undiagnosed cases.

Development of new hepatitis E vaccines

Hepatitis E virus (HEV) infection is an emerging zoonotic disease posing a severe threat to public health in the world, especially to pregnant women. Currently, no specific treatments are available for HEV infection. Therefore, it is crucial to develop vaccine to prevent this infection. Although several potential candidate vaccines against HEV have been studied for their immunogenicity and efficacy, only Hecolin® which is developed by Xiamen Innovax Biotech Co., Ltd. and approved by China Food and Drug Administration (CFDA) in 2012, is the licensed HEV vaccine in the world so far. Extensive studies on safety, immunogenicity and efficacy in phase III clinical trials have shown that Hecolin® is a promising vaccine for HEV prevention and control. In this article, the advances on HEV vaccine development and research are briefly reviewed.

Autochthonous acute hepatitis E: an increasingly frequent diagnosis. Clinical-epidemiological analysis of our experience

BACKGROUND

In Europe, acute hepatitis caused by the hepatitis E virus (HEV) traditionally was an infection found in people who had travelled to endemic zones, mainly Asia and Africa. However, a growing number of sporadic autochthonous cases are now being diagnosed in the Western world.

OBJECTIVE

To analyze the cases of acute HEV hepatitis diagnosed in our setting, with the identification of the clinical-epidemiological characteristics.

MATERIAL AND METHODS

We included the cases of acute HEV hepatitis diagnosed (positive anti-HEV IgM and/or HEV RNA present in serum) between January 2008 and December 2014. Different clinical, epidemiological and evolutive parameters were analyzed.

RESULTS

A total of 23 patients were identified, all originating from Spain. Fourteen cases (60.87%) presented jaundice and marked cytolysis at the time of diagnosis (aspartate aminotransferase [AST] 1,106.91 U/l and alanine aminotransferase [ALT] 1,407.04 U/l). Twenty-two cases were regarded as autochthonous, and one patient had travelled to China three months before. The mean time to resolution was 11.2 weeks. Some autoimmune markers were positive in 43.5% of the patients. Two subjects were diagnosed with previous chronic liver disease and were classified as "acute-on-chronic liver failure" (ACLF), one died and the other underwent liver transplantation.

CONCLUSION

Acute HEV hepatitis in our setting is an autochthonous condition that is probably underdiagnosed, manifesting with jaundice and cytolysis. Autoimmune marker positivity is an epiphenomenon, which in some cases complicates the diagnosis.

The added value of hepatitis E diagnostics in determining causes of hepatitis in routine diagnostic settings in the Netherlands

OBJECTIVES

Hepatitis E virus (HEV) genotype 3 is endemic in Europe and an underdiagnosed and emerging (public) health issue. In recent years commercial enzyme immunoassays (EIAs) that detect antibodies to HEV more adequately, became available. We investigated the added value of this HEV serology in the diagnostic work flow to detect viral causes of recent hepatitis.

METHODS

During a 2-year period (May 2013 to May 2015), HEV serology was added to the hepatitis work flow, consisting of serological detection of hepatitis viruses A, B and C (HAV, HBV, HCV), Epstein-Barr virus (EBV) and cytomegalovirus (CMV). Samples positive for HEV IgM were also analysed using PCR to detect HEV RNA. If positive, HEV sequencing was performed for genotyping purposes.

RESULTS

In 235 out of 2521 patients (9.3%), a viral cause for hepatitis was found. Recent HAV, HBV, HCV, EBV or CMV infections were serologically diagnosed in 3, 34, 10, 69 and 42 patients, respectively. Seventy-eight patients (3.1%) had a recent HEV infection. In 49 of them, sufficient HEV RNA was present for genotyping. All patients were infected with HEV genotype 3.

CONCLUSIONS

In our region, an HEV infection is the most frequently diagnosed viral cause for recent hepatitis. These results indicate that, in a country where HEV is endemic, serological HEV diagnostics should be added to the standard work-up for viral hepatitis.

Hepatitis E Virus in Industrialized Countries: The Silent Threat

Hepatitis E virus (HEV) is the main cause of acute viral hepatitis worldwide. Its presence in developing countries has been documented for decades. Developed countries were supposed to be virus-free and initially only imported cases were detected in those areas. However, sporadic and autochthonous cases of HEV infection have been identified and studies reveal that the virus is worldwide spread. Chronic hepatitis and multiple extrahepatic manifestations have also been associated with HEV. We review the data from European countries, where human, animal, and environmental data have been collected since the 90s. In Europe, autochthonous HEV strains were first detected in the late 90s and early 2000s. Since then, serological data have shown that the virus infects quite frequently the European population and that some species, such as pigs, wild boars, and deer, are reservoirs. HEV strains can be isolated from environmental samples and reach the food chain, as shown by the detection of the virus in mussels and in contaminated pork products as sausages or meat. All these data highlight the need of studies directed to control the sources of HEV to protect immunocompromised individuals that seem the weakest link of the HEV epidemiology in industrialized regions.

Hepatitis E virus infection in patients with acute non-A, non-B, non-C hepatitis in Central Brazil

Hepatitis E virus (HEV) infection has a worldwide distribution and represents an important cause of acute hepatitis. This study aims to investigate the occurrence of HEV infection and factors associated with this infection in patients with acute non-A, non-B, non-C hepatitis in Central Brazil. From April 2012 to October 2014, a cross-sectional study was conducted among 379 patients with acute non-A, non-B, non-C hepatitis in the City of Goiania, Central Brazil. Serum samples of all patients were tested for serological markers of HEV infection (anti-HEV IgM and IgG) by ELISA. Positive samples were confirmed using immunoblot test. Anti-HEV IgM and IgG positive samples were tested for HEV RNA. Of the 379 serum samples, one (0.3%) and 20 (5.3%) were positive for anti-HEV IgM and IgG, respectively. HEV RNA was not found in any sample positive for IgM and/or IgG anti-HEV. After multivariate analysis, low education level was independently associated with HEV seropositivity (p = 0.005), as well as living in rural area, with a borderline p-value (p = 0.056). In conclusion, HEV may be responsible for sporadic self-limited cases of acute hepatitis in Central Brazil.

Evaluation of rapid tests for diagnosis of acute hepatitis E

BACKGROUND

Hepatitis E virus diagnosis still presents difficulties due to discordant results among diagnostic tests.

OBJECTIVES

The aim of this study was to evaluate the performance of two rapid tests for detection of anti-HEV IgM antibodies.

STUDY DESIGN

The rapid tests were compared with three commercial anti-HEV ELISA assays and one Real-Time PCR assay on 59 sera from patients with acute viral non-AC hepatitis.

RESULTS

The presence of anti-HEV IgM antibodies was evaluated by two rapid tests (Wantai and Assure) on 25 HEV RNA positive samples. Anti-HEV IgM antibodies were detected in 24/25 and 23/25 samples respectively. The sensitivity and specificity of Wantai and Assure Rapid tests were evaluated using the 25 HEV RNA positive samples and 50 HEV RNA negative samples (including sera from acute-phase HAV and HBV infections and blood donors). Overall, the sensitivity of Wantai Rapid and Assure Rapid tests was 96.1% and 92.6% respectively; the specificity of the 2 tests was 100%.

CONCLUSION

Our data suggest the potential use of anti-HEV IgM rapid assays as a first line test in primary health care settings, particularly useful for patients with chronic liver disease or pregnant women who urgently need an antiviral treatment.

Hepatitis E virus as a Cause of Acute Hepatitis in The Netherlands

BACKGROUND

Recent studies indicate that 27% of Dutch blood donors have evidence of past infection with HEV. However, the low number of diagnosed HEV infections indicates either an asymptomatic course or under diagnosis.

OBJECTIVES

We investigated whether HEV is a cause of acute hepatitis in Dutch patients and which diagnostic modality (serology or PCR) should be used for optimal detection.

STUDY DESIGN

Serum samples were retrospectively selected from non-severely immuno-compromised patients from a university hospital population, suspected of having an infectious hepatitis. Criteria were: elevated alanine aminotransferase (ALT> 34 U/l) and request for antibody testing for CMV, EBV or Hepatitis A (HAV).

RESULTS

All samples were tested for HEV using ELISA and PCR. Ninety patients/sera were tested, of which 22% were HEV IgG positive. Only one serum was IgM positive. HEV PCR was positive in two patients: one patient was both HEV IgM and IgG positive, the other patient was only IgG positive. Both HEV RNA positive samples belonged to genotype 3. Evidence of recent infection with CMV, EBV and HAV was found in 13%, 10% and 3% respectively.

CONCLUSIONS

Although our study is limited by small numbers, we conclude that HEV is a cause of acute hepatitis in hospital associated patients in The Netherlands. Moreover, in our study population the prevalence of acute HAV (3%) was almost similar to acute HEV (2%). We propose to incorporate HEV testing in panels for acute infectious hepatitis. Negative results obtained for HEV IgM in a HEV PCR positive patient, indicates that antibody testing alone may not be sufficient and argues for PCR as a primary diagnostic tool in hospital associated patients. The high percentage of HEV IgG seropositivity confirms earlier epidemiological studies.

Epidemiology of Hepatitis E Virus in European Countries

Over the last decade the seroprevalence of immunoglobulin (IgG) anti hepatitis E virus (HEV) has been increasing in European countries and shows significant variability among different geographical areas. In this review, we describe the serological data concerning the general population and risk groups in different European countries. Anti-HEV antibody prevalence ranged from 1.3% (blood donors in Italy) to 52% (blood donors in France). Various studies performed on risk groups in Denmark, Moldova and Sweden revealed that swine farmers have a high seroprevalence of HEV IgG (range 13%-51.1%), confirming that pigs represent an important risk factor in HEV infection in humans. Subtypes 3e,f are the main genotypes detected in the European population. Sporadic cases of autochthonous genotype 4 have been described in Spain, France, and Italy. Although most HEV infections are subclinical, in immune-suppressed and transplant patients they could provoke chronic infection. Fulminant hepatitis has rarely been observed and it was related to genotype 3. Interferon and ribavirin treatment was seen to represent the most promising therapy.

Current Knowledge on Hepatitis E

Although only a single serotype of hepatitis E virus (HEV), the causative agent of hepatitis E, has been identified, there is great genetic variation among the different HEV isolates reported. There are at least four major recognized genotypes of HEV: genotypes 1 and 2 are mainly restricted to humans and linked to epidemic outbreaks in nonindustrialized countries, whereas genotypes 3 and 4 are zoonotic in both developing and industrialized countries. Besides human strains, genotype 3 and 4 strains of HEV have been genetically characterized from swine, sika deer, mongooses, sheep, and rabbits. Currently, there are approximately 11,000 human and animal sequences of HEV available at the International Nucleotide Sequence Database Collaboration. HEV is the major cause of waterborne outbreaks of hepatitis in areas of poor sanitation. Additionally, it is responsible for sporadic cases of viral hepatitis in not only endemic but industrialized countries as well. Transmission of HEV occurs predominantly by the fecal-oral route, although parenteral and perinatal routes have been reported. HEV infection develops in most individuals as a self-limiting, acute, icteric hepatitis; with mortality rates around 1%. However, some affected individuals will develop fulminant hepatic failure, a serious condition that is frequently fatal without a liver transplant. This complication is particularly common when the infection occurs in pregnant women, where mortality rates rise dramatically to up to 25%. Among the preventive measures available to avoid HEV infection, two separate subunit vaccines containing recombinant truncated capsid proteins of HEV have been shown to be highly effective in the prevention of disease. One of them, HEV 239, was approved in China, and its commercialization by Innovax began in November 2012 under the name Hecolin(®).

Hepatitis E in patients with hepatic disorders and HIV-infected patients in Croatia: is one diagnostic method enough for hepatitis E diagnosis?

We assessed hepatitis E virus (HEV) seroprevalence in patients with hepatic disorders as well as in human immunodeficiency virus (HIV)-infected patients and emphasised the issue of possible non-specific anti-HEV seroresponse and need for combining diagnostic methods for hepatitis E diagnosis. Over a two-year period, from March 2011 to February 2013, we determined anti-HEV immunoglobulin M (IgM) and IgG by enzyme immunoassays (EIA; Mikrogen, Germany) in 504 hepatitis patients negative for acute viral hepatitis A-C. Furthermore, 88 samples from randomly selected consecutive HIV-infected patients were also analysed. All EIA reactive samples were additionally tested by line immunoblot assays (LIA; Mikrogen, Germany). HEV nested reverse transcription polymerase chain reaction (RT-PCR) was carried out in 14 anti-HEV IgM LIA-positive patients. Anti-HEV IgM or IgG were detected in 16.9 % of patients by EIA and confirmed by LIA in 10.7 % [95 % confidence interval (CI) 8.3-13.7 %] of hepatitis patients. HEV RNA was detected in five patients. The agreement between EIA and LIA assessed by Cohen's kappa was 0.47 (95 % CI 0.55-0.75) for IgM and 0.83 (95 % CI 0.78-0.93) for IgG. Anti-HEV IgM and IgG seroprevalence in HIV-infected patients was 1.1 %, respectively. Our findings show a rather high HEV seroprevalence in patients with elevated liver enzymes in comparison to HIV-infected patients. Discordant findings by different methods stress the need to combine complementary methods and use a two-tier approach with prudent interpretation of reactive serological results for hepatitis E diagnosis.

Autochthonous Hepatitis E Virus Infection in Europe: A Matter of Concern for Public Health?

Human hepatitis E virus (HHEV) is the proposed name for a diverse group of RNA viruses from the family Hepeviridae that cause acute hepatitis among humans. Waterborne strains are regularly imported into Europe by international travelers, and virus transmission of zoonotic strains via contaminated aliments is involved in autochthonous cases. Therefore, in Europe, hepatitis E displays a unique dual character, having features of both imported and autochthonous infections. Environmental involvement of waterborne and zoonotic diseases puts alimentary safety at risk. In addition, it may lead to serious health problems derived from persistent infection among patients with immune impairment due to organ transplant, cancer, or human immunodeficiency virus infection. Although the European health authorities know at present that HHEV represents a problem worthy of consideration, the actual incidence of the disease in Europe is unknown, and attempts to ascertain the prevalence of the infection is hampered by unresolved technical issues. In order to determine the burden of hepatitis E in Europe, the World Health Organization Regional Office and the European Centre for Disease Prevention and Control should pay specific attention to hepatitis E, and research efforts in the continent should be transnational and collaborative. Development of a specific European network for hepatitis E would help to achieve these goals.

Light and Darkness: Prevalence of Hepatitis E Virus Infection among the General Population

Human hepatitis E virus (HHEV) spreads early in life among the population in areas endemic for genotype 1 and infects mainly adults in areas endemic for genotype 3, where it would be responsible for about 10% of cases of suspected acute viral hepatitis of unknown etiology and for a number of subclinical, unrecognized infections. The overall prevalence of antibody to HHEV is high in most of the former areas and low in most of the later ones, but wide regional differences have been recorded in both cases. "Hot spots" of HHEV infection would exist for both types of strains in particular regions or among particular populations of the world. Studies on pork derivatives, shellfish bivalves, and vegetables for HHEV contamination at the sale point need to be extended for evaluating the impact of the agent on food safety, and the meaning of the finding of HHEV genotype 1 genomes in urban sewage from developed countries should be established through active surveillance. Consensus about technical issues in regard to anti-HEV testing would improve the knowledge of the HHEV epidemiology. Studies in particular regions and populations, and introduction of molecular diagnosis in the clinical setting as a routine tool, would also be required.

Hepatitis E virus infection in Latin America: a review

Data reported during recent years reveal the complex picture of the epidemiology of hepatitis E virus (HEV) infection in Latin America. Whereas in countries like Argentina and Brazil is almost identical to the characteristic of most countries from North America and Europe, HEV in the Caribbean and Mexico involves the water-borne, non-zoonotic viral genotypes responsible for epidemics in Asia and Africa. Nevertheless, Latin America has been considered a highly endemic region for hepatitis E in the scientific literature, a generalization that ignores the above complexity. In addition, reports from isolated Amerindian communities, which display well known, important and very specific epidemiological features for hepatitis B and D virus infections are neither taken into account when considering the epidemiology of hepatitis E in the region. This review updates compilation of the available information for the HEV infection, both among humans and other mammals, in Latin America, discusses the strengths and the weaknesses of our current knowledge, and identifies future areas of research.

An exploratory case control study of risk factors for hepatitis E in rural Bangladesh

Hepatitis E virus (HEV) is the major cause of epidemic and sporadic hepatitis globally. Outbreaks are associated with fecal contamination of drinking water, yet the environmental reservoir of HEV between epidemics remains unclear. In contrast to neighboring countries, where epidemics and sporadic disease co-occur, HEV-endemic communities in rural Bangladesh seldom report outbreaks; sporadic hepatitis E is reported from urban and rural areas of the country. Besides typical enteric risk factors, other routes for HEV infection and disease are unclear. We conducted monthly household surveillance of a southern Bangladeshi community of 23,500 people to find incident cases of acute hepatitis E over a 22 month period. An algorithm was used to capture 279 candidate cases, of which 46 were confirmed acute HEV infections. An exploratory case-control study was conducted to identify putative risk factors for disease. Nearly 70% of cases were over 15 years old. Female gender seemed protective (OR:0.34) against hepatitis E in this conservative setting, as was the use of sanitary latrines (OR:0.28). Socioeconomic status or animal exposures were not significant predictors of disease, although outdoor employment and recent urban travel were. Unexpectedly, recent contact with a “jaundiced” patient and a history of injection exposure in the 3 months prior to disease (OR:15.50) were significant. Susceptible individuals from “endemic” communities share similar enteric exposure risks to those commonly associated with tourists from non-endemic countries. This study also raises the novel possibility of parenteral and person-to-person transmission of HEV in non-epidemic, sporadic disease settings.

[Hepatitis E: scale of the problem in Spain]

Hepatitis E virus (HEV) infection is one of the most frequent causes of acute hepatitis worldwide. However, in Spain, HEV causes only a tiny number of cases of acute hepatitis, the most prevalent cause being hepatitis A. Most cases of HEV in Spain are "imported", being acquired through travel to areas where this infection is endemic. Nevertheless, in the last few years a growing number of "autochthonous cases" have been reported in persons with no history of travelling to HEV-endemic areas. The prevalence of IgG antibodies against HEV, indicating exposure to this virus, is approximately 0.6-7.3% in the general population in Spain and is 19% in persons with risk factors such as exposure to pigs.

Diagnosis of HEV infection by serological and real-time PCR assays: a study on acute non-A-C hepatitis collected from 2004 to 2010 in Italy

Background

The impact of hepatitis E in developed countries, like Italy, still requires a clear definition. In the present study, we evaluated HEV infection in patients with acute non-A-C hepatitis by an approach comparing data from Real-time PCR and serological assays.

Methods

In a first analysis, sera from 52 patients hospitalized with a diagnosis of acute viral non-A-C hepatitis in Italy were tested by in-house Real-Time PCR assay for identification of Hepatitis E Virus (HEV) RNA and by anti-HEV IgM and IgG assays. In a subsequent analysis, selected samples were evaluated by additional IgM tests to confirm diagnosis.

Results

Among the 52 samples, 21 showed positive results for all three markers (IgM, IgG and HEV RNA). One patient showed HEV RNA as single marker. Uncertain results were found in 8 samples while the remaining 22 were negative for all markers. Further analysis of the 8 undefined samples by additional IgM tests confirmed HEV infection in 1 patient. Overall, acute HEV infections were reliably identified in 23 (44.2%) out of 52 patients.

Conclusions

In the present paper, we performed a study evaluating HEV infection in 52 sporadic non-A-C acute hepatitis cases. All samples were collected from 2004 to 2010 in Italy. By a diagnostic strategy based on genomic and serological assays we identified HEV infections in 23 out of 52 patients (44.2%), a percentage higher than previous estimates. Thus, the actual impact of HEV infections in Italy needs to be further evaluated on a national scale by a diagnostic strategy based on multiple and last generation assays.

Immunohistochemistry for the diagnosis of hepatitis E virus infection

Hepatitis E virus (HEV) is an emerging pathogen and the most common cause of acute viral hepatitis all over the world. We describe here an immunohistochemical method for the detection of HEV antigens (pORF2 and pORF3) in formalin-fixed, paraffin-embedded liver tissues using monoclonal antibodies raised against two of the virus proteins (pORF2 and pORF3). We analysed their specificity and sensitivity in comparison with serology and nucleic acid detection in cases of acute liver failure (ALF). We used this test on 30 liver biopsies collected post-mortem from the patients of ALF caused by HEV infection. These cases were selected on the basis of positive results for enzyme immunoassay (IgM anti-HEV). Of the 30 cases taken from the archives of the Department of Pathology, the antibodies successfully stained all. However, only 25 serum samples (83.3%) of these were positive for HEV RNA. Fifteen controls used (Five noninfected liver tissues, five HBV- and five hepatitis C virus-infected liver tissues) were all negative. The immunohistochemical assay described here may prove a valuable tool for the detection of HEV infection in biopsy, autopsy and explant liver tissues and can serve as a link along with other available tests to delineate the extent of HEV-associated problem worldwide.

Hepatitis E virus infection as a cause of acute hepatitis in Southern Italy

BACKGROUND

Hepatitis E virus (HEV) is a major cause of acute hepatitis in developing countries, whereas it is not considered a major health problem in Western World.

AIMS

To investigate the spread of HEV and its possible role in causing acute hepatitis in Southern Italy.

METHODS

Four hundred and thirty patients observed from April to December 2009 were studied and grouped as follows: 55 individuals with acute hepatitis (AH), 33 of whom cryptogenic; 321 individuals with chronic liver diseases (CLD), (278 Italians and 43 immigrants); 54 individuals without liver disease (control-group). Serum samples from all cases were tested for IgG anti-HEV antibodies and those positive to this test as well as all AH cases were also tested both for IgM anti-HEV and HEV RNA.

RESULTS

Two of 33 (6%) cryptogenic AH cases were associated with HEV infection as shown by positive IgM anti-HEV test. Both these patients had not travelled to areas at high HEV endemicity. HEV RNA was not found in any sample tested. IgG anti-HEV antibodies were detected in 5.7% of Italians with CLD and 3.7% of the control-group. No immigrant was found positive for any HEV marker.

CONCLUSION

Autochthonous HEV infection is present in Southern Italy where it may cause AH.

Identifications of polyphyletic variants in acute hepatitis suggest an underdiagnosed circulation of hepatitis E virus in Argentina

BACKGROUND

In recent years, an increasing number of infections with genotype 3 hepatitis E virus (HEV) have been reported in western countries. Data in South America, however, are still scarce. Swine and human variants previously described in Argentina are closely related to a human Austrian one.

OBJECTIVE

To identify whether HEV is still circulating in Argentina.

STUDY DESIGN

Sera and stool samples from adults and children with unexplained acute liver disease referred to our center during the last six years were prospectively studied. Dual infection with hepatitis A was retrospectively studied in a group of children with fulminant hepatic failure.

RESULTS

Fifteen new cases (13 adults and 2 children), seven of whom required hospitalization, were diagnosed. Nine had detectable HEV RNA, and one had imported genotype 1. Subgenotype 3i HEV-related variants are still circulating. Five autochthonous sequences, related to European, American and Japanese ones, grouped in subgenotype 3a. One case had a subgenotype 3b variant.

DISCUSSION

The polyphyletic variants widespread in Argentina suggest multiple sources of infection. Whether or not their reservoir is swine merits further investigation. Since hepatitis E is still considered rare, differential laboratory testing in unexplained acute liver disease is not routinely performed in Argentina. Broadening awareness of this disease is important in light of the decrease in hepatitis A incidence since universal vaccination was implemented in 2005. The diagnosis of hepatitis E with a combination of serological and molecular tools is needed to better understand its epidemiology and impact on the clinical management of patients with unexplained increased transaminases.

Serological diagnostics of hepatitis E virus infection

Development of accurate diagnostic assays for the detection of serological markers of hepatitis E virus (HEV) infection remains challenging. In the course of nearly 20 years after the discovery of HEV, significant progress has been made in characterizing the antigenic structure of HEV proteins, engineering highly immunoreactive diagnostic antigens, and devising efficient serological assays. However, many outstanding issues related to sensitivity and specificity of these assays in clinical and epidemiological settings remain to be resolved. Complexity of antigenic composition, viral genetic heterogeneity and varying epidemiological patterns of hepatitis E in different parts of the world present challenges to the refinement of HEV serological diagnostic assays. Development of antigens specially designed for the identification of serological markers specific to acute infection and of IgG anti-HEV specific to the convalescent phase of infection would greatly facilitate accurate identification of active, recent and past HEV infections.