Screening, diagnosis and risks associated with Hepatitis E virus infection

Comparison of two automated commercial assays for routine detection of anti-hepatitis E Virus IgM antibodies in clinical samples

Diagnosis of hepatitis E virus (HEV) infection relies first on detection of IgM antibodies (Ab), sometimes completed with HEV RNA detection. This study aimed to compare the performance of two automated anti-HEV IgM Ab assays. Correlation between Virclia® (Vircell) and Liaison® (Diasorin) assays was carried out on 178 routine clinical samples. Both assays were run on 67 samples from HEV RT-PCR (Altona) screened patients, and 52 Wantai® EIA (Euroimmun) tested samples. An excellent correlation was observed between both assays with an overall agreement of 96.6% (172/178), and a kappa coefficient at 0.93. In HEV RNA positive group (n=43), IgM detection rate was 93.3% (14/15) in immunocompetent patients, with both assays. In immunocompromised patients, detection rate was 75% (21/28) and 71.4% (20/28) using Virclia® and Liaison XL® assays, respectively. Virclia® and Liaison® anti-HEV IgM assays have similar performance for the detection of anti-HEV IgM Ab.

Evaluation of an automated platform for the detection of HEV RNA in plasma and stool

INTRODUCTION

We evaluated the performance of the automated Altostar HEV RNA platform for detecting HEV RNA.

METHODS AND RESULTS

Clinical performance was determined by testing 81 plasma samples and 10 fecal samples manually quantified previously with the Realstar RT-PCR assay using the Magnapure instrument for extraction. The assays were concordant for 79/81 plasma samples (97.5%) and 10/10 (100%) fecal samples. The two plasma samples that tested negative with the Altostar assay had a very low HEV RNA concentration (1.6 and 1.4 log10 IU/ml). Quantitative results obtained with the automated platform and the manual workflow were highly correlated (ρ= 0.98, p<0.01). The intra-run and inter-run standard deviation were 0.09 IU/ml and 0.13 IU/ml respectively. The assay was linear from 2 to 6 log IU/ml. The limit of detection determined by Probit analysis with the WHO HEV RNA standard was 7.6 [95% CI: 4.4-52.5] IU/ml.

CONCLUSIONS

The Altostar platform enables highly accurate testing for the detection of HEV RNA in stool and the quantification of HEV RNA in plasma. This allowed us to shorten turnaround times and to save time for the technical staff.

Clustered Cases of Waterborne Hepatitis E Virus Infection, France

The identification of seven cases of hepatitis E virus infection in a French rural hamlet in April 2015 led to investigations confirming the clustering and identifying the source of the infection. Laboratories and general practitioners in the area actively searched for other cases based on RT-PCR and serological tests. The environment, including water sources, was also checked for HEV RNA. Phylogenetic analyses were performed to compare HEV sequences. No other cases were found. Six of the seven patients lived in the same hamlet, and the seventh used to visit his family who lived there. All HEV strains were very similar and belonged to the HEV3f subgenotype, confirming the clustering of these cases. All the patients drank water from the public network. A break in the water supply to the hamlet was identified at the time the infection probably occurred; HEV RNA was also detected in a private water source that was connected to the public water network. The water flowing from the taps was quite turbid during the break. The private water supply containing HEV RNA was the likely source of the contamination. Private water supplies not disconnected from the public network are still frequent in rural areas, where they may contribute to public water pollution.

Hepatitis E Virus Research in Brazil: Looking Back and Forwards

Hepatitis E virus (HEV) has emerged as a public health concern in Brazil. From the first identification and characterization of porcine and human HEV-3 strains in the 2000s, new HEV subtypes have been identified from animal, human, and environmental isolates. As new potential animal reservoirs have emerged, there is a need to compile evidence on the zoonotic dissemination of the virus in animal hosts and the environment. The increasing amount of seroprevalence data on sampled and randomly selected populations must be systematically retrieved, interpreted, and considered under the One Health concept. This review focused on HEV seroprevalence data in distinct animal reservoirs and human populations reported in the last two decades. Furthermore, the expertise with experimental infection models using non-human primates may provide new insights into HEV pathogenesis, prevention, and environmental surveillance.

Diagnostic and management strategies for chronic hepatitis E infection

INTRODUCTION

Hepatitis E Virus (HEV) was initially thought to cause only acute infections, but the discovery of chronic hepatitis E in immunocompromised patients has profoundly changed our understanding of the virus.

AREAS COVERED

We describe the physiopathology, diagnosis, and clinical management of chronic HEV infection. The virus can persist in nearly two-thirds of immunosuppressed patients. Reducing immunosuppression is the first immunomodulatory strategy to cure chronic hepatitis E. But this may not always be feasible or effective. Ribavirin monotherapy for 3 months has been recommended as first-line treatment for chronically infected patients. Ribavirin is around 80% effective at eradicating HEV in retrospective studies. Apart from ribavirin, interferon has been successfully used in liver transplants recipients, but if the patient does not respond, no other alternative drug is available. The vaccine available to prevent HEV infection is one available only in China.

EXPERT OPINION

HEV infection is a major concern in immunocompromised patients. But the therapeutic arsenal is limited to ribavirin and interferon. Both produce several side effects and new drugs are urgently needed. Moreover, preventive strategies to limit HEV transmission and/or evolution to a chronic infection are also required.

Prevalence of HEV RNA in Croatian blood donors

OBJECTIVES

HEV infection is asymptomatic for immunocompetent blood donors (BD). Transfused HEV-infected blood products may cause potentially hazardous HEV infection in immunocompromised patients. Evaluation of the need for routine BD HEV RNA screening primarily demands the establishment of HEV infection prevalence in Croatian BD.

MATERIALS AND METHODS

We tested BD samples in ID-NAT with the Procleix UltrioPlex E screening test for simultaneous detection of HBV DNA, HCV RNA, HIV-1,2 RNA, and HEV RNA (Grifols, Spain). HEV infection was confirmed with HEV RNA quantitative test (Altona Diagnostics, Germany) and HEV IgM and HEV IgG antibody test (DIA.PRO Diagnostic Bioprobes, Italy). We analysed the HEV RNA sequence and performed a phylogenetic analysis. We recorded BD's anamnestic data and dietary habits. BDs gave follow-up samples after two months and did not donate blood for six months.

RESULTS

Between December 2021 and March 2022, we tested 8,631 donations and found four HEV RNA-positive donations, which equals to one in 2,158 donations (0.046 %, 95 % confidence interval, 0.018 %-0.119 %). Confirmatory HEV RNA testing gave results from negative to 4.73E + 3 IU/ml HEV RNA. Three donations were in the serological window period. We have genotyped HEV RNA of two infected BD as genotype HEV-3c. Blood donors didn't report any health problems and their diet included pork. Testing on follow-up samples presented seroconversion and no HEV RNA could be detected.

CONCLUSION

The incidence of HEV RNA infection in BD in Croatia corresponds with other European data. The decision on implementation of HEV NAT screening in Croatia needs an expert team evaluation of the possible risk of TT-HEV infection.

Hepatitis E virus in the endangered Iberian lynx (Lynx pardinus)

Hepatitis E virus (HEV) is an emerging zoonotic pathogen in Europe. In the Iberian Peninsula, wild boar (Sus scrofa) is considered the main wildlife reservoir of HEV. This wild ungulate shares habitat and resources with other potential HEV carriers in Iberian Mediterranean ecosystems, although information about the role of such sympatric species in the HEV epidemiological cycle is still very limited. The aims of the present large-scale, long-term study were: (1) to determine the seroprevalence and prevalence of HEV in both free-living and captive populations of the Iberian lynx (Lynx pardinus), the most endangered felid in the world; (2) to determine potential risk factors associated with HEV exposure in this species and (3) to evaluate the dynamics of seropositivity in longitudinally sampled animals during the study period. Between 2010 and 2021, serum samples from 275 Iberian lynxes were collected in free-ranging and captive populations across the Iberian Peninsula. Forty-four of the 275 lynxes were also longitudinally sampled during the study period. A double-antigen sandwich ELISA was used to test for the presence of antibodies against HEV. A subset of seropositive samples was analysed by Western blot (WB) assay to confirm exposure to HEV. In addition, serum, liver and/or faecal samples from 367 individuals were tested for orthohepevirus RNA by RT-PCR. A total of 50 (18.2%; 95% CI: 14.1-23.2) of the 275 animals analysed had anti-HEV antibodies by ELISA. Exposure to HEV was confirmed by WB in most of the ELISA-positive Iberian lynxes analysed. Significantly higher seroprevalence was found in captive (33.6%) compared to free-ranging (7.4%) individuals. Within captive population, the GEE model identified 'age' (senile, adult and subadult) as risk a factor potentially associated with HEV exposure in the Iberian lynx. Thirteen (29.5%) of 44 longitudinally surveyed individuals seroconverted against HEV during the study period. HEV RNA was detected in the faeces of one (1/364; 0.3%; 95% CI: 0.0-0.8) free-ranging adult animal sampled in 2021. Phylogenetic analysis showed that the sequenced strain belongs to HEV-3f subtype and shared a high nucleotide sequence identity (97-99.6%) with human HEV-3f sequences from Spain and France. To the best of the authors' knowledge, this is the first survey study on HEV in the Iberian lynx and the first molecular report of HEV-A infection in free-ranging felines. Our results indicate high exposure to HEV-3 in Iberian lynx populations, particularly those kept in captivity. The serological results suggest widespread but not homogeneous circulation of HEV in Iberian lynx populations. Further studies are required to assess the epidemiological role of this endangered species as a potential spillover host of HEV.

Diagnostic Performance of an Automated System for Assaying Anti-Hepatitis E Virus Immunoglobulins M and G Compared with a Conventional Microplate Assay

To evaluate the diagnostic performance of the Liaison® Murex anti-HEV IgM and IgG assays running on the Liaison® instrument and compare the results with those obtained with Wantai HEV assays. We tested samples collected in immunocompetent and immunocompromised patients during the acute (HEV RNA positive, anti-HEV IgM positive) and the post-viremic phase (HEV RNA negative, anti-HEV IgM positive) of infections. The specificity was assessed by testing HEV RNA negative/anti-HEV IgG-IgM negative samples. The clinical sensitivity of the Liaison® IgM assay was 100% for acute-phase samples (56/56) and 57.4% (27/47) for post-viremic samples from immunocompetent patients. It was 93.8% (30/32) for acute-phase (viremic) samples and 71%% (22/31) for post-viremic samples from immunocompromised patients. The clinical sensitivity of the Liaison® IgG assay was 100% for viremic samples (56/56) and 94.6% (43/47) for post-viremic samples from immunocompetent patients. It was 84.3% (27/32) for viremic samples and 93.5% (29/31) for post-viremic samples from immunocompromised patients. Specificity was very high (>99%) in both populations. We checked the limit of detection stated for the Liaison® IgG assay (0.3 U/mL). The clinical performance of the Liaison® ANTI-HEV assays was good. These rapid, automated assays for detecting anti-HEV antibodies will greatly enhance the arsenal for diagnosing HEV infections.

Zoonotic transmission of hepatitis E virus in a pig farmer from Argentina: A case report

Hepatitis E virus (HEV) is a public health concern due to its zoonotic transmission to human, being pigs a highly recognized reservoir. We previously demonstrated HEV genotype 3 infections in pig herds from the highest commercial active region from Argentina. Here, we present a case of acute symptomatic hepatitis E in an elderly man with occupational exposure to pigs who referred regular consumption of pork and sausages. HEV infection in this patient was demonstrated by serological methods, as well as by HEV RNA detection in serum and stool samples using the HEV/MS2 duplex RT-qPCR, formerly optimized in our laboratory. We further detected HEV RNA in pig faeces from the patient´s farm. To confirm the potential role of swine in the transmission, we performed a phylogenetic analysis of all HEV RNA derived from both, the patient and the pig samples. A 303 nt region within the HEV 5 'ORF2 was amplified by nested RT-PCR and subsequently sequenced. Phylogenetic analysis showed that the strains isolated from the farmer and from his pigs presented a nucleotide identity of 100%. These results support the zoonotic transmission of circulating HEV strains and confirm this epidemiological association for the first time in Argentina.

Hepatitis E Virus Infection: Neurological Manifestations and Pathophysiology

Hepatitis E virus (HEV) is the first cause of viral hepatitis in the world. While the water-borne HEV genotypes 1 and 2 are found in developing countries, HEV genotypes 3 and 4 are endemic in developed countries due to the existence of animal reservoirs, especially swine. An HEV infection produces many extra-hepatic manifestations in addition to liver symptoms, especially neurological disorders. The most common are neuralgic amyotrophy or Parsonage–Turner syndrome, Guillain–Barré syndrome, myelitis, and encephalitis. The pathophysiology of the neurological injuries due to HEV remains uncertain. The immune response to the virus probably plays a role, but direct virus neurotropism could also contribute to the pathophysiology. This review describes the main neurological manifestations and their possible pathogenic mechanisms.

Limited Value of Single Sampling for IgM Antibody Determination as a Diagnostic Approach for Acute Hepatitis E Virus Infection

The objective was to evaluate the accuracy of a single determination of IgM antibodies for hepatitis E virus (HEV) diagnosis in patients with acute hepatitis. A prospective study included patients with suspicion of HEV infection, defined as individuals with acute hepatitis showing negative results for serological and molecular markers of other hepatitis viruses. All patients were evaluated for hepatitis E virus infection, including both IgM antibodies and viral RNA determinations. Hepatitis E virus infection was defined as positivity for any of these markers. A total of 182 patients were included in the study, of whom 68 (37.4%) were diagnosed with HEV infection. Of these, 29 (42.6%) were positive for both IgM and HEV RNA, 25 (36.8%) were positive only for IgM antibodies, and 14 (20.6%) were positive only for HEV RNA. Considering only those individuals who were positive for IgM antibodies, 54 of the 68 total cases (79.4%) could be identified, showing a percentage of false-negative individuals of 20.6%. The diagnostic algorithm of hepatitis E virus infection in patients with acute hepatitis should include the determination of both IgM antibodies and HEV RNA because single sampling for IgM antibody determination led to an important proportion of misdiagnosed cases. IMPORTANCE In immunocompetent patients with a suspicion of hepatitis E virus (HEV) infection, single IgM antibody testing is typically applied. In this prospective study, we aimed to evaluate the accuracy of three different HEV screening approaches in patients with acute hepatitis, including approaches based on IgM determination, HEV RNA detection, and the combination of both. Our study shows that any diagnostic algorithm for HEV infection in patients with acute hepatitis should be based on the determination of both markers (IgM antibodies and HEV RNA) because single sampling for IgM antibodies results in an unacceptable number of false-negative results (20%). According to our results, the determination of HEV RNA should not be limited to immunosuppressed individuals because a high proportion of cases could be misdiagnosed.

Hepatitis E: An update on One Health and clinical medicine

The hepatitis E virus (HEV) is one of the main causes of acute hepatitis and the de facto global burden is underestimated. HEV-related clinical complications are often undetected and are not considered in the differential diagnosis. Convincing findings from studies suggest that HEV is clinically relevant not only in developing countries but also in industrialized countries. Eight HEV genotypes (HEV-1 to HEV-8) with different human and animal hosts and other HEV-related viruses are in circulation. Transmission routes vary by genotype and location, with large waterborne outbreaks in developing countries and zoonotic food-borne infections in developed countries. An acute infection can be aggravated in pregnant women, organ transplant recipients, patients with pre-existing liver disease and immunosuppressed patients. HEV during pregnancy affects the fetus and newborn with an increased risk of vertical transmission, preterm and stillbirth, neonatal jaundice and miscarriage. Hepatitis E is associated with extrahepatic manifestations that include neurological disorders such as neuralgic amyotrophy, Guillain-Barré syndrome and encephalitis, renal injury and haematological disorders. The risk of transfusion-transmitted HEV is increasingly recognized in Western countries where the risk may be because of a zoonosis. RNA testing of blood components is essential to determine the risk of transfusion-transmitted HEV. There are currently no approved drugs or vaccines for HEV infections. This review focuses on updating the latest developments in zoonoses, screening and diagnostics, drugs in use and under development, and vaccines.

Incidence and prevalence of acute hepatitis E virus infection in patients with suspected Drug-Induced Liver Injury in the Spanish DILI Registry

BACKGROUND AND AIMS

Drug-induced liver injury (DILI) presents with a wide phenotypic spectrum requiring an extensive differential diagnosis. Hepatitis E virus (HEV) is not systematically ruled out during acute hepatitis assessment in Spain. The aims of this study were to establish the role of HEV infection and its phenotypic presentation in patients initially suspected of DILI and to determine the anti-HEV seroprevalence rate.

METHODS

An analysis of 265 patients with suspected DILI and considered for enrolment in the Spanish DILI Registry and 108 controls with normal liver profiles was undertaken. Anti-HEV Immunoglobulin (Ig) G antibodies were analysed in serum from all subjects. In those with serum samples extracted within 6 months from liver damage onset (n = 144), HEV antigen (Ag) and anti-HEV IgM antibodies were tested in duplicate by ELISA. In addition, RT-PCR was performed externally in eight patients.

RESULTS

Out of 144 patients, 12 (8%) were positive for anti-HEV IgM, mean age was 61 years. Underlying hepatic diseases (OR = 23.4, P < .001) and AST peak >20 fold upper limit of normal (OR = 10.9, P = .002) were associated with the diagnosis of acute hepatitis E. The overall anti-HEV IgG seroprevalence rate was 35%, evenly distributed between patients with suspected DILI (34%), and controls (39%).

CONCLUSIONS

HEV seroprevalence and acute hepatitis E rates are relatively high in Spain. A search for active HEV infection is therefore advised in patients assessed for suspicion of DILI, particularly in patients with underlying liver diseases and high transaminase levels.

Hepatitis E, what is the real issue?

Hepatitis E virus (HEV) infection is a worldwide disease and the primary cause of acute viral hepatitis with an estimated 3.3 million symptomatic cases every year and 44,000 related deaths. It is a waterborne infection in the developing countries. In these countries, HEV genotypes 1 and 2 cause large outbreaks and affect young subjects resulting in significant mortality in pregnant women and patients with cirrhosis. In developed countries, HEV genotypes 3 and 4 are responsible for autochthonous, sporadic hepatitis and transmission is zoonotic. Parenteral transmission by the transfusion of blood products has been identified as a potential new mode of transmission. HEV can also cause neurological disorders and chronic infections in immunocompromised patients. The progression of acute hepatitis E is usually asymptomatic and resolves spontaneously. Diagnosis is based on both anti-HEV IgM antibodies in serum and viral RNA detection in blood or stools by PCR in immunocompetent patients, while only PCR is validated in immunocompromised individuals. Ribavirin is the only validated treatment in chronic infection. A vaccine has been developed in China.

Towards the Improved Accuracy of Hepatitis E Diagnosis in Vulnerable and Target Groups: A Global Perspective on the Current State of Knowledge and the Implications for Practice

The hepatitis E virus (HEV) is a positive single-stranded, icosahedral, quasi-enveloped RNA virus in the genus Orthohepevirus of the family Hepeviridae. Orthohepevirus A is the most numerous species of the genus Orthohepevirus and consists of eight different HEV genotypes that can cause infection in humans. HEV is a pathogen transmitted via the fecal-oral route, most commonly by consuming fecally contaminated water. A particular danger is the HEV-1 genotype, which poses a very high risk of vertical transmission from the mother to the fetus. Several outbreaks caused by this genotype have been reported, resulting in many premature births, abortions, and also neonatal and maternal deaths. Genotype 3 is more prevalent in Europe; however, due to the openness of the market, i.e., trade-in animals which represent a natural reservoir of HEV (such as pigs), there is a possibility of spreading HEV infections outside endemic areas. This problem is indeed global and requires increased hygiene measures in endemic areas, which entails special care for pregnant women in both endemic and non-endemic regions. As already highlighted, pregnant women could have significant health consequences due to the untimely diagnosis of HEV infection; hence, this is a population that should be targeted with a specific combination of testing approaches to ensure optimal specificity and sensitivity. Until we advance from predominantly supportive treatment in pregnancy and appraise the safety and efficacy of a HEV vaccine in this population, such screening approaches represent the mainstay of our public health endeavors.

Prognostic Significance of End-Stage Liver Diseases, Respiratory Tract Infection, and Chronic Kidney Diseases in Symptomatic Acute Hepatitis E

Symptomatic hepatitis E virus (HEV) infection is sporadic, and usually occurs in a limited number of infected patients, which hinders the investigation of risk factors for clinical outcomes in patients with acute HEV infection. A retrospective cohort study enrolling 1913 patients with symptomatic acute hepatitis E in Beijing 302 Hospital from January 1, 2001 to December 31, 2018 was conducted. The baseline characteristics, clinical features and laboratory data of these HEV infection cases were analyzed. Albumin (ALB), platelet (PLT), alanine aminotransferase (ALT), total bilirubin (T-BiL), international normalized ratio (INR) and serum creatinine (SCR) levels, along with the model for end-stage liver disease (MELD) score, hospitalization days, co-morbidity number and mortality were taken as major parameters for comparing the clinical manifestations in our study. We found that not all pre-existing chronic liver diseases exacerbate clinical manifestations of acute hepatitis E. Alcoholic hepatitis, fatty liver hepatitis, hepatic cyst, drug-induced hepatitis and hepatocellular carcinoma were not significantly associated with mortality of HEV patients. Among all of the comorbidities, end-stage liver diseases (ESLDs, including ascites, cirrhosis, hepatic coma and hepatorenal syndrome), respiratory tract infection and chronic kidney diseases (CKDs, including renal insufficiency and renal failure) were found to remarkably increase the mortality of patients with symptomatic HEV infection. Furthermore, the severity evaluation indexes (SEI), such as MELD score, duration of hospital stay, and co-morbidity number in HEV patients with underlying comorbidities were much worse than that of their counterparts without relevant comorbidities.

Hepatitis E, what's the real issue?

Hepatitis E Virus (HEV) infection is a worldwide disease and the primary cause of acute viral hepatitis in the world with an estimated 20 million cases every year and 70 000 deaths. Hepatitis E is a waterborne infection in the developing countries. In these countries, HEV genotypes 1 and 2 cause large outbreaks and affect young subjects, resulting in significant mortality in pregnant women and patients with cirrhosis. In the developed countries, HEV genotypes 3 and 4 are responsible for autochthonous, sporadic hepatitis and transmission is zoonotic. Parenteral transmission by the transfusion of blood products has been identified as a potential new mode of transmission. The prevalence of positive HEV viraemia in blood donors in Europe ranges from 1/600 to 1/2500 in highly endemic European countries. HEV can cause neurological disorders and chronic infections in immunocompromised patients. The progression of acute hepatitis E is usually asymptomatic and resolves spontaneously. Diagnostic tools include anti-HEV IgM antibodies in serum and/or viral RNA detection in the blood or the stools by PCR. Ribavirin is used to treat chronic infection. A vaccine has been developed in China.

Clinical Manifestations, Pathogenesis and Treatment of Hepatitis E Virus Infections

Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis throughout the world. Most infections are acute but they can become chronic in immunocompromised patients, such as solid organ transplant patients, patients with hematologic malignancy undergoing chemotherapy and those with a human immunodeficiency virus (HIV) infection. Extra-hepatic manifestations, especially neurological and renal diseases, have also been described. To date, four main genotypes of HEV (HEV1-4) were described. HEV1 and HEV2 only infect humans, while HEV3 and HEV4 can infect both humans and animals, like pigs, wild boar, deer and rabbits. The real epidemiology of HEV has been underestimated because most infections are asymptomatic. This review focuses on the recent advances in our understanding of the pathophysiology of acute HEV infections, including severe hepatitis in patients with pre-existing liver disease and pregnant women. It also examines the mechanisms leading to chronic infection in immunocompromised patients and extra-hepatic manifestations. Acute infections are usually self-limiting and do not require antiviral treatment. Conversely, a chronic HEV infection can be cleared by decreasing the dose of immunosuppressive drugs or by treating with ribavirin for 3 months. Nevertheless, new drugs are needed for those cases in which ribavirin treatment fails.

Gene therapy in liver diseases focus on Adeno-Associate Virus Vector (AAV) and Virus-Like Particles (VLPS)

The liver has a critical role in several genetic inherited and acquired disorders. Over the years, the development of several therapies to treat liver diseases resulted in several successful treatment outcomes for liver disorders. However, its use has been severely hampering by many undesirable side effects and methodological restrictions. Currently, there are several advances for the treatment of hepatic diseases with genetic therapy, which address several problems. Research on recent new treatments has focused on the development of specific gene editing approaches that use novel genetic tools, as well as the efficient distribution systems of these tools in the liver. This paper will provide an overview of current and emerging therapeutic strategies such as Adeno-associated Virus Vectors (AAV), new serotypes of AVV for gene therapy and Virus-like particles (VLPs)