Hepatitis E virus infection in patients infected with the human immunodeficiency virus

Hepatitis E Virus (HEV) Infection Among Immunocompromised Individuals: A Brief Narrative Review

Hepatitis E virus (HEV) is a single-stranded positive-sense RNA virus that belongs to Hepeviridae family. HEV is the most common cause of acute viral hepatitis worldwide. According to the World Health Organization (WHO), there are estimated 20 million HEV infections worldwide every year, leading to estimated 3.3 million symptomatic cases of HEV infection. The WHO estimates that HEV infection caused approximately 44,000 deaths in 2015, which represents 3.3% of mortality rates due to viral hepatitis. In low-income (LI) countries and lower-middle-income (LMI) countries, HEV is a waterborne infection induced by HEV genotype (gt) 1 and HEV gt 2 that cause large outbreaks and affect young individuals with a high mortality rate in pregnant women from South Asian countries and patients with liver diseases. HEV gt 3, HEV gt 4, and HEV gt 7 are responsible for sporadic infections with zoonotic transmission mainly through the consumption of raw or undercooked meat from different animals. Acute HEV infection is relatively asymptomatic or mild clinical form, in rare cases the disease can be moderate/severe clinical forms and result in fulminant hepatitis or acute liver failure (ALF). Furthermore, HEV infection is associated with extrahepatic manifestations, including renal and neurological clinical signs and symptoms. Pregnant women, infants, older people, immunocompromised individuals, patients with comorbidities, and workers who come into close contact with HEV-infected animals are recognized as major risk groups for severe clinical form of HEV infection and fatal outcome. Chronic HEV infection can occur in immunocompromised individuals with the possibility of progression to cirrhosis.

Seroreversion of IgG anti-HEV in HIV cirrhotic patients: A long-term multi-sampling longitudinal study

The aim of our study was to evaluate HEV antibody kinetics in HIV/HCV-coinfected patients with cirrhosis. A longitudinal retrospective study was designed. Patients were followed up every 6 months; anti-HEV IgG and IgM antibodies levels and HEV-RNA by qPCR were analysed. The prevalence and incidence of every HEV infection marker were calculated. The kinetics of anti-HEV IgG and IgM during the follow-up were evaluated. Seventy-five patients comprised the study population. The seroprevalence observed was 17.3%. None showed IgM antibodies or HEV-RNA at baseline. None showed detectable HEV viral load during the study period. After a median follow-up of 5.1 years, two of 62 seronegative patients (3.2%) seroconverted to IgG antibody. The incidence for IgM was 2.7%. Of the 13 patients with IgG seropositivity at baseline, five (38.5%) seroreverted. Meanwhile, of the two patients who exhibited IgM positivity during the study, one (50%) showed intermittent positivity. We found that HEV seropositivity is common in HIV/HCV-coinfected cirrhotic patients. A remarkable rate of IgG seroreversions and IgM intermittence was found, limiting the use of antibodies for the diagnosis of HEV infection in this population.

Hepatitis E virus in Saudi Arabia: more surveillance needed

Hepatitis E virus (HEV) is a small quasi-enveloped ssRNA causing acute hepatitis. HEV is the leading cause of intermittent acute hepatitis and fulminant hepatic failure. Risk factors include drinking contaminated water in developing countries and consumption of infected animal products in developed countries. Previous reports on HEV prevalence in Saudi Arabia had small sample sizes. Nationwide systematic seroprevalence studies are needed to investigate risk factors and annual incidence. Camels play a cultural and economic role in the life of Saudi citizens with frequent human contact and potential role in zoonotic transmission. Future research needs to include larger sample-sizes and nationwide studies. Future studies should also focus on raising awareness of HEV infection and the need for wider population testing and screening.

Beyond the Usual Suspects: Hepatitis E Virus and Its Implications in Hepatocellular Carcinoma

Hepatitis E virus infections are the leading cause of viral hepatitis in humans, contributing to an estimated 3.3 million symptomatic cases and almost 44,000 deaths annually. Recently, HEV infections have been found to result in chronic liver infection and cirrhosis in severely immunocompromised patients, suggesting the possibility of HEV-induced hepatocarcinogenesis. While HEV-associated formation of HCC has rarely been reported, the expansion of HEV's clinical spectrum and the increasing evidence of chronic HEV infections raise questions about the connection between HEV and HCC. The present review summarizes current clinical evidence of the relationship between HEV and HCC and discusses mechanisms of virus-induced HCC development with regard to HEV pathogenesis. We further elucidate why the development of HEV-induced hepatocellular carcinoma has so rarely been observed and provide an outlook on possible experimental set-ups to study the relationship between HEV and HCC formation.

Hepatitis E seroprevalence and viremia rate in immunocompromised patients: a systematic review and meta-analysis

BACKGROUND AND AIMS

Hepatitis E is an infectious disease of the liver caused by the hepatitis E virus (HEV). Immunocompromised patients present a particular risk group, as chronification of hepatitis E leading to life-threatening cirrhosis occurs when these patients are infected. Therefore, this study aims to estimate and compare the anti-HEV seroprevalence and the rate of HEV RNA positivity in transplant recipients and patients with human immunodeficiency virus (HIV).

METHODS

This systematic review and meta-analysis involved a literature search (PubMed, Scopus; 1,138 studies) including 120 studies from 1996 to 2019, reporting anti-HEV seroprevalence and/or HEV-RNA positivity. Statistical analysis was performed using a linear mixed-effects meta regression model.

RESULTS

Anti-HEV seroprevalence in 14 626 transplant recipients ranged from 6% (95% CI: 1.9-17.2) to 29.6% (95% CI: 21.6-39.) in different commercially available assays and did not differ significantly compared to 20 825 HIV positive patients (range: 3.5% (95% CI: 0.9-12.8) - 19.4% (95% CI: 13.5-26.9). In contrast, HEV-RNA positivity rate was significantly higher in transplant recipients than in HIV positive patients (1.2% (95% CI: 0.9-1.6) vs 0.39% (95% CI: 0.2-0.7); P-value = 0.0011).

CONCLUSION

Anti-HEV seroprevalence did not differ significantly between transplant recipients and HIV positive patients. Interestingly, rates of HEV-RNA positivity, indicating ongoing infection, were significantly higher in transplant recipients. These findings demonstrate that transplant patients have an elevated risk of chronic infection in comparison to HIV patients at comparable risk of HEV-exposure.

No evidence of sexual transmission of HEV among individuals using HIV pre-exposure prophylaxis

We investigated the seroprevalence and incidence of hepatitis E virus (HEV) infection in men who have sex with men (MSM) who have been exposed to pre-exposure prophylaxis (PrEP) against HIV as sexual transmission of HEV has been suggested. A total of 147 PrEP-using MSM and 147 blood donors matched for sex, age and geographical area were tested for anti-HEV IgG and IgM. Among them, 135 have been followed for 1 year, at the end of which serological tests for HEV were performed retrospectively on stored samples. Laboratory data on sexual transmitted infections (STIs) and viral hepatitis, including hepatitis A virus (HAV), were collected. Baseline seroprevalence rates in PrEP users were 42.2% (anti-HEV IgG) and 3.4% (anti-HEV IgM). Those of the control blood donors were similar (anti-HEV IgG 43.5% and anti-HEV IgM 4.1%). There was no incident of HEV infection despite the rates of bacterial STIs (incidence rate (IR) = 46.6%) and HAV infection (IR = 15.8%). Age was the only risk factor associated with anti-HEV IgG seropositivity at baseline and at the end of follow-up. Sexual transmission does not seem to be a major route of HEV infection in MSM, unlike HAV.

Viral Hepatitis E and Chronicity: A Growing Public Health Concern

Hepatitis E viral infection recently emerges as a global health concern. Over the last decade, the understanding of hepatitis E virus (HEV) had changed with the discovery of new genotypes like genotype-7 and genotype-8 with associated host and mode of infection. Diversification in the mode of hepatitis E infection transmission through blood transfusion, and organ transplants in contrast to classical feco-oral and zoonotic mode is the recent medical concern. The wide spectrum of infection ranging from self-limiting to acute liver failure is now overpowered by HEV genotype-specific chronic infection especially in transplant patients. This concern is further escalated by the extra-hepatic manifestations of HEV targeting the central nervous system (CNS), kidney, heart, and pancreas. However, with the development of advanced efficient cell culture systems and animal models simulating the infection, much clarity toward understanding the pathogenetic mechanism of HEV has been developed. Also this facilitates the development of vaccines research or therapeutics. In this review, we highlight all the novel findings in every aspect of HEV with special emphasis on recently emerging chronic mode of infection with specific diagnosis and treatment regime with an optimistic hope to help virologists and/or liver specialists working in the field of viral hepatitis.

The Clinical Perspective on Hepatitis E

Every year, there are an estimated 20 million hepatitis E virus (HEV) infections worldwide, leading to an estimated 3.3 million symptomatic cases of hepatitis E. HEV is largely circulating in the west and is associated with several hepatic and extrahepatic diseases. HEV Genotype 1 and 2 infections are waterborne and causative for epidemics in the tropics, while genotype 3 and 4 infections are zoonotic diseases and are mainly transmitted by ingestion of undercooked pork in industrialized nations. The clinical course of these infections differs: genotype 1 and 2 infection can cause acute illness and can lead to acute liver failure (ALF) or acute on chronic liver failure (ACLF) with a high mortality rate of 20% in pregnant women. In contrast, the majority of HEV GT-3 and -4 infections have a clinically asymptomatic course and only rarely lead to acute on chronic liver failure in elderly or patients with underlying liver disease. Immunosuppressed individuals infected with genotype 3 or 4 may develop chronic hepatitis E, which then can lead to life-threatening cirrhosis. Furthermore, several extra-hepatic manifestations affecting various organs have been associated with ongoing or previous HEV infections but the causal link for many of them still needs to be proven. There is no approved specific therapy for the treatment of acute or chronic HEV GT-3 or -4 infections but off-label use of ribavirin has been demonstrated to be safe and effective in the majority of patients. However, in approximately 15% of chronically HEV infected patients, cure is not possible.

Detection and characterization of hepatitis E virus genotype 3 in HIV-infected patients and blood donors from southern Brazil

BACKGROUND

Hepatitis E virus genotype 3 (HEV-3) infection usually causes self-limited acute hepatitis. In immunosuppressed patients, HEV-3 infection can rapidly progress to chronic hepatitis and cirrhosis. In southern Brazil, data on HEV seroprevalence are scarce.

METHODS

Testing for HEV RNA and antibodies (anti-HEV) was performed for 320 HIV-infected patients followed at the HIV/AIDS Service of the Federal University of Rio Grande between 2012 and 2013, as well as 281 blood donor samples obtained in 2015. Variables associated with anti-HEV positivity were assessed by multivariable logistic regression analysis.

RESULTS

HIV and blood donor groups showed similar HEV seroprevalence (6.7% and 7.1%, respectively). Risk factors associated with anti-HEV detection were older age, marital status, a higher number of sexual partners, poor sanitation, and alcohol use (HIV group), and living in a rural area (blood donors). HEV RNA was detected in eight serum samples from HIV-infected patients and in one blood donor, who was also positive for anti-HEV IgM and IgG.

CONCLUSIONS

The prevalence rates of HEV infection were comparable between HIV-seropositive patients who were not severely immunocompromised and blood donors. The blood donor's HEV isolate showed high similarity with swine HEV strains from Brazilian herds in the same region, thus indicating a potential risk of foodborne and parenteral transmission via blood transfusion.

Hepatitis E Infection in HIV-Infected Patients

BACKGROUND

The hepatitis E virus (HEV) represents a major cause of acute hepatitis worldwide. The majority of HEV cases occur in low-income countries, mainly Asia and Africa, where HEV causes large outbreaks associated with the consumption of contaminated water and high mortality in specific populations. In high-income countries, HEV infection is considered a zoonotic disease that is linked to the consumption of contaminated food. Although a high proportion of cases have self-limiting asymptomatic or subclinical infections, immunosuppression may modify the pathogenesis and clinical impact of this emerging disease.

RESULTS AND DISCUSSION

Here, we review the current knowledge about the epidemiology, diagnosis, clinical manifestations, management and prevention of HEV infection in HIV-infected subjects.

CONCLUSIONS

Despite the increasing knowledge about the pathogenesis, epidemiology and clinical impact of HEV infection, several major factors are faced by HIV-infected patients, including treatment recommendations, immunization and risk practices.

Animal Models for Hepatitis E virus

Hepatitis E virus (HEV) is an underdiagnosed pathogen with approximately 20 million infections each year and currently the most common cause of acute viral hepatitis. HEV was long considered to be confined to developing countries but there is increasing evidence that it is also a medical problem in the Western world. HEV that infects humans belongs to the Orthohepevirus A species of the Hepeviridae family. Novel HEV-like viruses have been observed in a variety of animals and some have been shown to be able to cross the species barrier, causing infection in humans. Several cell culture models for HEV have been established in the past years, but their efficiency is usually relatively low. With the circulation of this virus and related viruses in a variety of species, several different animal models have been developed. In this review, we give an overview of these animal models, indicate their main characteristics, and highlight how they may contribute to our understanding of the basic aspects of the viral life cycle and cross-species infection, the study of pathogenesis, and the evaluation of novel preventative and therapeutic strategies.

Clinical features and determinants of chronicity in hepatitis E virus infection

Hepatitis E virus (HEV) has traditionally been associated with an acute, self-limiting hepatitis and is not known to have any chronic sequelae. HEV genotypes 1 and 2, which are human pathogens, have been associated with this self-limiting presentation, in both sporadic and epidemic settings. HEV genotype 3, which is zoonotically transmitted, is increasingly being reported as a cause of chronic infection in immunocompromised patients. These include patients with solid organ transplants, patients receiving chemotherapy for haematologic malignancies and patients infected with HIV. Chronic infection is associated with rapidly progressing liver disease and extrahepatic manifestations including neurologic disorders. We review the clinical manifestations of chronic HEV infection and discuss factors determining persistence and chronicity of HEV.

Seroprevalence of Hepatitis E Virus Infection Among People Living With HIV in the Central African Republic

Background

Hepatitis E virus (HEV) is a waterborne virus that causes acute hepatitis in immunocompromised patients and those who are immunocompetent. Few cases of chronic HEV have been described in industrialized countries. The Central African Republic is 1 of the few countries in the world that is endemic for both HIV and HEV. The prevalence of HIV infection is estimated to be 4.9% among adults aged 15-49 years, and hepatitis E is epidemo-endemic. The aim of this study was to characterize the epidemiology of HEV infection in people living with HIV (PLHIV) in Bangui.

Methods

A cross-sectional study was conducted between April and September 2015 based on answers to a questionnaire, and blood samples were collected for determination of immunological markers by enzyme-linked immunosorbent assay and molecular tests.

Results

Of the 200 PLHIV included, 15 (7.5%) had the IgM that characterizes acute HEV infection; 8.9% were women, and 2.2% were men. The overall seroprevalence of IgG was 68% (48% women and 70.4% men), indicating that men are statistically significantly more exposed to HEV than women. HEV infection had no effect on transaminase or T-CD4+ lymphocyte cell levels. The origin of infection could not be identified.

Conclusions

The seroprevalence of HEV is very high among PLHIV and in the general population of Bangui. This must be taken into account in studies of the risk factors of PLHIV infected with HEV.

Detection and quantification of hepatitis E virus in the absence of IgG and IgM anti-HEV in HIV-positive patients

AIMS

To improve RT-qPCR with an internal control and a synthetic standard curve to detect HEV in HIV co-infected patients.

METHODS AND RESULTS

A single-stranded RNA (ssRNA) and a double-stranded DNA (dsDNA) synthetic curve were designed, compared to the international reference panel for HEV genotypes, and tested to quantify and detect a reference panel for HEV genotypes. The detection limit of the RNA synthetic curve (50 copies per ml) was better than the DNA synthetic curve (100 copies per ml) and the WHO standard curve (250 copies per ml). Then, 280 serum samples from HIV-positive patients were tested for HEV RNA, which was detected in 3·6% of serum samples. The viral load ranged from 2 × 10² copies per ml to 4·78 × 10⁸ copies per ml. HEV IgM/IgG antibodies were not detected in the RNA-positive patients. Sequencing analysis of HEV showed that the virus belongs to genotype 3 (HEV GT3).

CONCLUSIONS

Real-time PCR was a useful tool to estimate co-infection with HEV/HIV, even in patients with low viral loads and undetectable anti-HEV IgG and IgM antibodies.

SIGNIFICANCE AND IMPACT OF THE STUDY

Hepatitis E virus genotype 3 (HEV GT3) has been associated with silent chronic hepatitis and cirrhosis in HIV-positive subjects worldwide, but there is a lack of data on this co-infection in Brazil.

Hepatitis E virus infection in HIV-infected patients: A large cohort study in Yunnan province, China

Hepatitis E virus (HEV) infection in immunocompromised patients often results in distinct outcome, compared to the infection in general population. This study aimed to investigate the prevalence, potential risk factors, and clinical features of HEV infection among HIV patients treated with antiretroviral therapy (ART) in Yunnan province, China. A total of 770 HIV-infected patients between May 2015 and February 2016 were enrolled in Yunnan, China. All patients received ART. All plasma samples were tested for anti-HEV IgG, anti-HEV IgM antibodies using ELISA kits, and HEV RNA by real-time qRT-PCR. Association between anti-HEV antibody positivity and demographic, clinical and laboratory measures was assessed in univariate and multivariate logistic regression models. Of the 770 HIV-infected patients, 342 patients (44.42%) were anti-HEV IgG antibody positive, and six patients (0.78%) were anti-HEV IgM antibody positive. None of the patients was HEV RNA positive, as tested in our assays. We found that age, gender, CD4 cell count, WHO stage, marital status, and total cholesterol levels were associated with HEV infection. We report a high seroprevalence rate and several potential risk factors of HEV infection in a large HIV cohort from Yunnan province in China. Further research on identification of the circulating HEV strains and the clinical outcome of this patient population is required.

Serological and molecular markers of hepatitis E virus infection in HIV-infected patients in Brazil

In Brazil, the circulation of hepatitis E virus (HEV) has been demonstrated in distinct groups of individuals and some animals, but its prevalence among individuals with human immunodeficiency virus (HIV) infection is unknown. This study aimed to assess the frequency of serological and molecular HEV markers in individuals infected with HIV from São Paulo, Brazil. Serum and plasma samples of 354 HIV-infected patients collected between 2007 and 2013 were included. All samples were tested for anti-HEV IgG and IgM antibodies and HEV RNA. Anti-HEV IgG and IgM antibodies were detected in 10.7% (38/354) and 1.4% (5/354) of the samples, respectively. Both antibodies were detected simultaneously in only two samples. HEV RNA was not detected in any sample. There was no significant correlation of anti-HEV serological status (positivity to anti-HEV IgG and/or IgM) with sex, age, CD4⁺ T cell count, HIV viral load, antiretroviral therapy, liver enzyme levels, or coinfection with hepatitis B virus and/or hepatitis C virus. Our study provides serological evidence of past and recent HEV infections in HIV-infected patients from São Paulo, Brazil. However, the occurrence of ongoing HEV infection appears be a rare event in this population.

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.

Liver involvement in human immunodeficiency virus infection

The advances in management of patients with acquired immunodeficiency syndrome (AIDS) with highly effective anti-retroviral therapy (HAART) have resulted in increased longevity of patients with human immunodeficiency virus (HIV) infection. AIDS-related illnesses now account for less than 50 % of the deaths, and liver diseases have emerged as the leading cause of death in patients with HIV infection. Chronic viral hepatitis, drug-related hepatotoxicity, non-alcoholic fatty liver disease, and opportunistic infections are the common liver diseases that are seen in HIV-infected individuals. Because of the shared routes of transmission, co-infections with hepatitis B virus (HBV) and hepatitis C virus (HCV) are very common in HIV-infected persons. Hepatitis C is the most common viral hepatitis seen in HIV-infected patients. With the availability of directly acting agents, treatment outcome of HCV is comparable to that seen in non HIV-infected patients. Careful monitoring is required for drug interactions and drug-induced hepatotoxicity and modification of drugs should be done where necessary. The results of liver transplantation in select HIV-infected patients can be comparable with those of HIV-negative patients.

Analysis of long-term follow-up and examination of pathological liver tissue in chronic hepatitis E

Hepatitis E is chronic in immunocompromised patients with HIV infection, organ transplant, or radiation and chemotherapy. General cases are not chronic. Fifty-five cases were collected and followed up for 4-14 years. It was found that chronic hepatitis E is more common in males, but a high degree of inflammatory activity and fibrosis was not evident. After 4-14 years of follow-up observation, cirrhosis or liver cancer did not appear. This is significantly different from the hepatitis B and C viruses. We speculated that the chronic mechanism in the general patients with hepatitis E might be different from that of immunocompromised cases.

Hepatitis E virus infection in the HIV-positive patient

Hepatitis E virus (HEV) is a RNA virus that can cause hepatitis. In immunocompetent individuals, infection with HEV usually leads to asymptomatic seroconversion. However, in immunosuppressed patients, such as transplant recipients, HEV can develop into a chronic infection. Studies regarding the seroprevalence and clinical implications of HEV in patients infected with the human immunodeficiency virus (HIV) are conflicting. Levels of CD4 count in blood seem to be the most widely associated risk factor, while other factors such as meat consumption or proximity to animals are less clearly associated with HEV infection. Progression to chronicity, as well as extrahepatic manifestations of HEV seem rare in HIV, and the implications of HEV in liver disease progression are poorly understood in the HIV-infected. In this review we describe the epidemiology, risk factors, and clinical implications of HEV infection in individuals infected with HIV.

Hepatitis E virus as an emerging zoonotic pathogen

Hepatitis E outbreaks are a serious public health concern in developing countries. The disease causes acute infections, primarily in young adults. The mortality rate is approximately 2%; however, it can exceed 20% in pregnant women in some regions in India. The causative agent, hepatitis E virus (HEV), has been isolated from several animal species, including pigs. HEV genotypes 3 and 4 have been isolated from both humans and animals, and are recognized as zoonotic pathogens. Seroprevalence studies in animals and humans indirectly suggest that HEV infections occur worldwide. The virus is primarily transmitted to humans via undercooked animal meats in developed countries. Moreover, transfusion- and transplantation-mediated HEV infections have recently been reported. This review summarizes the general characteristics of hepatitis E, HEV infection status in animals and humans, the zoonotic transmission modes of HEV, and HEV vaccine development status.

Acute and Chronic Hepatitis E Virus Infection in Human Immunodeficiency Virus-Infected U.S. Women

Exposure to hepatitis E virus (HEV) is common in the United States, but there are few data on prevalence of HEV/human immunodeficiency virus (HIV) coinfection in U.S.

POPULATIONS

We tested 2,919 plasma samples collected from HIV-infected (HIV(+)) women and men enrolled in U.S. cohort studies for HEV viremia using a high-throughput nucleic acid testing (NAT) platform. NAT(+) samples were confirmed by real-time polymerase chain reaction. Samples were selected for testing primarily on the basis of biomarkers of liver disease and immune suppression. Prevalence of HEV viremia was 3 of 2,606 and 0 of 313 in tested plasma samples collected from HIV(+) women and men, respectively. All HEV isolates were genotype 3a. Based on follow-up testing of stored samples, 1 woman had chronic HEV infection for >4 years whereas 2 women had acute HEV detectable at only a single study visit.

CONCLUSIONS

To our knowledge, this is the first reported case of chronic HEV infection in an HIV(+) U.S. individual. We also confirm that chronic HEV infection can persist despite a CD4(+) count >200 cells/mm(3). Overall, though, these data suggest that HEV infection is rare in the HIV(+) U.S. population.

Hepatitis E virus: An ancient hidden enemy in Latin America

Hepatitis E virus (HEV) infection is a common cause of acute clinical hepatitis worldwide. HEV is an RNA-containing virus and the only member of the genus Hepevirus in the family Hepeviridae. Human HEV is classified into four genotypes widely distributed across the world. The virus is mainly transmitted via the fecal-oral route, and water-borne epidemics have become characteristic of hepatitis E in developing countries, including those in Latin America. The zoonotic potential of HEV is broadly recognized. Thus, there is an urgent need to re-evaluate virus transmission scenarios and to enforce epidemiological surveillance systems. Additionally, it is known that HEV infections, initially defined as self-limiting, can also take chronic courses in immunocompromised patients. Moreover, we recently reported a high seroprevalence of HEV in samples from cirrhotic patients with no other etiological agents present, suggesting the potential role of HEV in the development of chronic liver illness. In this review, HEV genomic variability, transmission, chronic infectious course, zoonotic potential and treatment are discussed. Focus is placed on the impact of HEV infection in Latin America, to support the development of specific control strategies and the handling of this important and typically imperceptible viral infection.

Is hepatitis E virus an emerging problem in industrialized countries?

Hepatitis E virus (HEV) is yearly responsible for approximately 20 million infections worldwide. Although most infections occur in developing countries, HEV appears to be an emerging problem in several industrialized countries, where it is mostly associated with either traveling to an HEV endemic area or contact with pigs, which represent a major reservoir of HEV. The major risk groups for HEV infection and its ensuing complications are elderly men, pregnant women, young children, immunocompromised patients, patients with preexisting liver disease, and workers that come into close contact with HEV-infected animals. Whereas HEV mainly causes acute self-limiting infections, chronic infections may occur among immunocompromised patients (e.g., transplant recipients and human immunodeficiency virus [HIV]-infected patients). Accordingly, HEV-HIV coinfection leads to accelerated liver cirrhosis and increased mortality rates compared to HEV infection alone, which is, except during pregnancy, usually associated with only low mortality. In the Western world, the most common genotype (gt) causing HEV infection is gt 3. Ribavirin (RBV) and interferon have been used successfully for treatment of HEV, but this treatment is contraindicated in certain patient groups. Therefore, novel antiviral compounds are highly needed, especially given that viral isolates with RBV resistance have been recently identified. Moreover, eradication of HEV is hampered by long-term environmental persistence of the virus, which represents a continuous source of the virus. In 2011, the first prophylactic HEV vaccine, Hecolin, was approved in China, but it is not yet globally available. In this review, we will discuss the molecular virology of HEV, mode of transmission in industrialized countries, and potential implications for different specific patient populations.

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.

Chronic hepatitis E: A brief review

Hepatitis E viral infection has traditionally been considered an acute, self-limited, water borne disease similar to hepatitis A, endemic to developing countries. However, over the past decade, zoonotic transmission and progression to chronicity in human patients has been identified, resulting in persistently elevated transaminase levels, progressive liver injury and cirrhosis. In addition to liver injury, neurological, renal and rheumatological manifestations have also been reported. Chronic hepatitis E occurs mainly in immunosuppressed individuals such as transplant recipients, human immunodeficiency virus patients with low CD4 counts and in patients with hematological malignancies receiving chemotherapy. Diagnosis is established by persistent elevation of hepatitis E virus RNA in the stool or serum. This population often requires treatment with antiviral agents, particularly ribavirin, as spontaneous clearance with reduction in immunosuppression occurs only in about a third of the patients. The purpose of this review, is to further discuss the clinical presentation, and recent advances in diagnosis, treatment and prophylaxis of chronic hepatitis E.

Chronically infected wild boar can transmit genotype 3 hepatitis E virus to domestic pigs

Hepatitis E virus (HEV) causes acute hepatitis E in humans in developing countries, but sporadic and autochthonous cases do also occur in industrialized nations. In Europe, food-borne zoonotic transmission of genotype 3 (gt3) has been associated with the consumption of raw and undercooked products from domestic pig and wild boar. As shown recently, naturally acquired HEV gt3 replicates efficiently in experimentally infected wild boar and is transmissible from a wild boar to domestic pigs. Generally, following an acute infection swine suffer from a transient febrile illness and viremia in connection with fecal virus shedding. However, little is known about sub-acute or chronic HEV infections in swine, and how and where HEV survives the immune response. In this paper, we describe the incidental finding of a chronic HEVgt3 infection in two naturally infected European wild boar which were raised and housed at FLI over years. The wild boar displayed fecal HEV RNA excretion and viremia over nearly the whole observation period of more than five months. The animal had mounted a substantial antibody response, yet without initial clearance of the virus by the immune system. Further analysis indicated a subclinical course of HEV with no evidence of chronic hepatitis. Additionally, we could demonstrate that this chronic wild boar infection was still transmissible to domestic pigs, which were housed together with this animal. Sentinel pigs developed fecal virus shedding accompanied by seroconversion. Wild boar should therefore be considered as an important reservoir for transmission of HEV gt3 in Europe.

Hepatitis E virus co-infection in HIV-infected patients in Foggia and Naples in southern Italy

BACKGROUND

Hepatitis E virus (HEV) infection represents an emerging infection in developed countries and is thought to be a zoonotic infection. It has recently been described as a new causative agent of acute and chronic hepatitis in immunosuppressed subjects, including HIV-infected patients. The aim of this study was to assess the sero-virological prevalence of HEV in HIV patients and in the general population as control group.

METHODS

A prospective and observational cohort study was carried out in two hospitals in southern Italy. The seroprevalence of HEV was determined in a cohort of 959 subjects, 509 (53%) of whom were HIV-positive patients and 450 were from the general population. Serum samples were tested for anti-HEV antibodies; repeatedly positive results were confirmed by a Western blot assay. In positive patients HEV RNA and genotypes were also determined.

RESULTS

A total of 46 (4.8%) of the 959 serum samples examined were reactive to anti-HEV Ig and confirmed by Western blotting. The prevalence of HEV antibodies (IgG and/or IgM) was 2.7% in the control group and 6.7% in HIV-infected patients. Anti-HEV IgM was found in 6/46 (13.0%) of the anti-HEV Ig-positive serum samples, in 5/34 HIV patients and in 1/12 of the general population. No HIV-infected patient presented chronic hepatitis with HEV infection alone.

CONCLUSIONS

This study indicates a higher circulation of HEV in HIV-infected patients, whereas a low prevalence of HEV antibodies in the general Italian population was shown. Chronic hepatitis with HEV alone was absent, while it was present in subjects with HIV-HEV, co-infected with hepatitis B virus (HBV) and/or hepatitis C virus (HCV).

Seroprevalence of hepatitis E in HIV infected patients in Greece

HEV infection is an emerging public health problem worldwide Data concerning HEV infection in HIV+ patients in Greece is scare. The aim of the study was to determine HEV seroprevalence in patients with HIV infection in Greece. We studied 243 HIV(+) patients 214 men (88%) and 29 women (12%) with a median age of 45 years (range 19-83) who attended the HIV unit of Pathophysiology Department of Laikon General Hospital in Athens for the presence of anti-HEV IgG antibodies with (EIA) (EIA HEV IgG, Adaltis, Rome, Italy Eighteen/243 patients (7.3%) were positive for HEV IgG antibodies, a seroprevalence that was not different from that described for the blood donors group from Greece There was no difference of the presence of HbsAg, hepatitis C and hepatitis A between the HEV(+) and HEV(-) patients. There was no statistically significant difference between the HEV(+) and HEV(-) group in terms of HIV acquisition, sexual orientation, median duration of HIV infection, ART treatment, or duration of ART. Only the median age of HEV(+) was 52 years (35-78) while that of HEV(-) was 44 years (19-83)(P = 0.03). Only 2/18(11.1%) HEV(+) HIV(+) patients had abnormal ALT and AST values. The seroprevalence of hepatitis E in HIV(+) patients in Greece seems to be the same with that of the general population thus implying that HIV infection is not a risk factor for HEV infection and only age shows a positive correlation with seropositivity.

Hepatitis E virus: chronic infection, extra-hepatic manifestations, and treatment

Hepatitis E virus (HEV) infection is a worldwide disease. An improved understanding of the natural history of HEV infection has been achieved within the last decade. Several reservoirs and transmission modes have been identified. It is an underdiagnosed disease because of the use of low-sensitivity serological assays; however, diagnostics tools, including nucleic-acid tests, have improved. HEV infection is usually an acute self-limiting disease, but causes chronic infection with rapidly progressive cirrhosis in adult and pediatric organ-transplant-patients. HEV infection evolves to chronic hepatitis in nearly 60% of HEV-infection solid-organ-transplant patients. HEV can also cause extra-hepatic manifestations, such as neurological symptoms and kidney injury. Reducing immunosuppression in transplant patients can lead to HEV clearance in one-third of patients with chronic hepatitis. The use of anti-viral therapies, such as pegylated-interferon and ribavirin, has been found to efficaciously treat HEV infection.

High prevalence of antibodies against hepatitis E virus in HIV-infected patients with unexplained liver disease

OBJECTIVE

To look for evidence of hepatitis E virus (HEV) exposure in HIV-infected patients with unexplained elevations of liver stiffness (LS).

METHODS

Case-control study conducted in 31 HIV-infected patients with unexplained elevations of LS and in 31 HIV-controls with normal LS, matched by age, sex and CD4 cell-counts. Serum HEV antibodies were tested by two ELISA procedures and by Immunoblot. We defined exposure to HEV as the detection of serum HEV antibodies by at least one of the two ELISA assays, provided that it was confirmed by Immunoblot. A real-time PCR RNA assay was conducted in all plasma samples to identify subjects with active HEV infection.

RESULTS

Exposure to HEV was demonstrated, according to the criteria used in this study, in 9 (29%) of the cases, whereas it was shown in 5 (16%) of the controls (p=.3). Serum HEV RNA was detected in none of the controls and in only in one case. This patient had a documented chronic hepatitis E with progression to cirrhosis.

CONCLUSIONS

HEV antibodies are frequently found in HIV-infected patients with unexplained liver disease.

The impact of hepatitis E in the liver transplant setting

Hepatitis E virus (HEV) infection has been identified as a cause of graft hepatitis in liver transplant recipients. The true frequency and clinical importance of HEV infections after liver transplantations is a matter of debate. It is proposed that consumption of HEV-contaminated undercooked meat is a main source for HEV infections in developed countries--which might also account for some hepatitis E cases after organ transplantation. However, HEV is also transmitted by transfusion of blood products, likely representing a previously underestimated risk particularly for patients in the transplant setting. HEV infection can take chronic courses in immunocompromised individuals, associated in some cases with rapid progression to cirrhosis within 1-2 years of infection. Diagnosis in transplanted patients is based on HEV RNA testing as antibody assays are not sensitive enough. Selection of immunosuppressive drugs is important as different compounds may influence viral replication and the course of liver disease. Ribavirin has antiviral activity against HEV and should be administered for at least three months in chronically infected individuals; however, treatment failure may occur. HEV infections have also been linked to a variety of extrahepatic manifestations both during and after resolution of infection. In this review we summarize the emerging data on hepatitis E with a particular focus on the importance of HEV infections for liver transplant recipients.

High hepatitis E virus seroprevalence with absence of chronic infection in HIV-infected patients

BACKGROUND & AIMS

The seroprevalence of the hepatitis E virus (HEV) and its chronicity rate in the HIV-infected population has not been well established. As a result, the magnitude of this emerging disease in this population cannot be established.

METHODS

Prospective study that included HIV-infected patients followed up between September 2012 and May 2013. All included patients were tested for anti-HEV IgG/IgM. In patients with confirmed anti-HEV IgG/IgM positivity, RT-PCR was performed. In patients where HEV RNA was amplified, a second RT-PCR assay was performed 6 months later to identify transient or chronic HEV infections.

RESULTS

Eight hundred and ninety-four HIV-infected patients were enrolled in the study. Of these patients, 399 (44.6%) were monoinfected with HIV; 462 (51.6%) were co-infected with HIV/HCV; 12 (1.3%) were co-infected with HIV/HBV; and 21 (2.3%) were co-infected with HIV/HCV/HBV. In 88 patients, anti-HEV IgG/IgM was detected (seroprevalence: 9.8% [95% CI: 8.02%-11.9%]). In five patients (0.5%; 95% CI: 0.2%-1.2%), HEV RNA was detected; 5.7% (95% CI: 2.1%-12.1%) of the patients were anti-HEV IgG/IgM positive. None of these patients showed detectable HEV RNA six months later.

CONCLUSION

HEV infection is frequent in HIV-infected patients but developing a chronic HEV infection may be considered an uncommon liver disease in this population.

Hepatitis viruses and liver transplantation: evolving trends in antiviral management

Viral hepatitis is both a leading indication for liver transplant (LT) and an important cause of posttransplant graft loss and mortality. Treatment and prevention of hepatitis B virus in LT recipients, with the observed corresponding improvement in post-LT outcomes, is among the great success stories in transplantation. By comparison, treatment of hepatitis C virus with safe and effective regimens is only just becoming a reality. Chronic hepatitis E virus infection in LT recipients represents a newly described phenomenon that can also lead to graft loss; early diagnosis and treatment may be key in the management of these patients.

SPF rabbits infected with rabbit hepatitis E virus isolate experimentally showing the chronicity of hepatitis

This study focused on investigating the pathogenesis seen in specific-pathogen-free (SPF) rabbits following infection with a homologous rabbit HEV isolate (CHN-BJ-rb14) and comparing it to that seen following infection with a heterologous swine genotype 4 HEV isolate (CHN-XJ-SW13). Three of the four animals inoculated with the homologous rabbit HEV became infected, exhibiting an intermittent viremia, obvious fluctuations of liver function biomarkers alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and persistent fecal virus shedding throughout the nine month study. In addition, liver histopathology showed both chronic inflammation and some degree of fibrosis. Both positive and negative-stranded HEV RNA and HEV antigen expression were detected in liver, brain, stomach, duodenum and kidney from the necropsied rabbits. Inflammation of extrahepatic tissue (duodenum and kidney) was also observed. Three of the four rabbits inoculated with the heterologous genotype 4 swine HEV also became infected, showing similar levels of anti-HEV antibody to that generated following infection with the homologous virus isolate. The duration of both viremia and fecal shedding of virus was however shorter following infection with the heterologous virus and there was no significant elevation of liver function biomarkers. These results suggest that rabbit HEV infection may cause more severe hepatitis and prolong the course of the disease, with a possible chronic trend of hepatitis in SPF rabbits.

Hepatitis E virus infection

Hepatitis E virus (HEV) infection is a worldwide disease. An improved understanding of the natural history of HEV infection has been achieved within the last decade. Several reservoirs and transmission modes have been identified. Hepatitis E is an underdiagnosed disease, in part due to the use of serological assays with low sensitivity. However, diagnostic tools, including nucleic acid-based tests, have been improved. The epidemiology and clinical features of hepatitis E differ between developing and developed countries. HEV infection is usually an acute self-limiting disease, but in developed countries it causes chronic infection with rapidly progressive cirrhosis in organ transplant recipients, patients with hematological malignancy requiring chemotherapy, and individuals with HIV. HEV also causes extrahepatic manifestations, including a number of neurological syndromes and renal injury. Acute infection usually requires no treatment, but chronic infection should be treated by reducing immunosuppression in transplant patients and/or the use of antiviral therapy. In this comprehensive review, we summarize the current knowledge about the virus itself, as well as the epidemiology, diagnostics, natural history, and management of HEV infection in developing and developed countries.

Epidemiology and associated risk factors of hepatitis e virus infection in plateau state, Nigeria

A cross-sectional study in Nigeria was undertaken to determine the epidemiology, seroprevalence, and associated risk factors, of hepatitis E virus (HEV). A total of 462 subjects were used for the study, categorized into four groups: apparently healthy persons, pregnant women, HIV positive subjects, and animal handlers. Information was obtained from subjects using interviewer-administered questionnaire. Blood samples were collected and analyzed for HEV antibodies (IgG and IgM) using enzyme-linked immunosorbent assay (ELISA) technique. Results obtained were analyzed using Statistical Package for Social Sciences (SPSS) version 17.0 statistical software. The overall seroprevalence of IgG and IgM was 42.7 and 0.9%, respectively. Animal handlers had the highest seroprevalence (66.7%). The associated risk factors for IgM seroprevalence were rural dwelling (P = 0.039, odds ratio (OR) 3.3, 95% confidence interval (CI) 0.7–15.4), blood transfusion (P < 0.001, OR 9.6, 95% CI 2.6–35.6), attending to animals (P = 0.032, OR 4.9, 95% CI 0.9–26.6), and waste disposal (P < 0.001). Factors associated with IgG were age (P = 0.044), location (P < 0.001), marital status (P < 0.001), formal education (P < 0.001), farming as occupation (P < 0.001), rural dwelling (P = 0.001), waste disposal (P < 0.001), alcohol consumption (P = 0.001, OR 2.4, 95% CI 1.4–4.0), open defecation (P < 0.001, OR 2.9, 95% CI 1.4–5.7), attending to animals (P < 0.001, OR 2.3, 95% CI 1.6–3.4), consuming unwashed fruits/vegetables (P < 0.001, OR 4.2, 95% CI 0.3–54.1), and stream/river as a source of drinking water (P < 0.001, OR 3.6, 95% CI 1.6–7.8). Preventive public health measures should be reinforced among all communities, particularly domestic animal handlers and pregnant women. Potable water should be provided for all communities. Data suggest that HEV remains an under-recognized and significant public health problem, warranting further attention and research.

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.

Fatal fulminant hepatitis E associated with autoimmune hepatitis and excessive paracetamol intake in Southeastern France

We present, to our knowledge, the first case of fatal fulminant liver failure associated with hepatitis E virus infection, autoimmune hepatitis, and excessive paracetamol intake, which occurred in a 77-year-old woman. Hepatitis E testing should be performed in severe acute liver failure cases, even when another cause has been identified.

Hepatitis E virus serological testing in kidney transplant recipients with elevated liver enzymes in 2007-2011 in southeastern France

Hepatitis E virus (HEV) is an emerging cause of acute and chronic hepatitis in Europe, particularly in solid organ transplant recipients. Anti-HEV IgG/IgM testing in kidney transplant recipients with liver biological disturbances indicated high HEV exposure in our geographical area and led to diagnose HEV infection in 6% of cases.

Host immune status and response to hepatitis E virus infection

Hepatitis E virus (HEV), identified over 30 years ago, remains a serious threat to life, health, and productivity in developing countries where access to clean water is limited. Recognition that HEV also circulates as a zoonotic and food-borne pathogen in developed countries is more recent. Even without treatment, most cases of HEV-related acute viral hepatitis (with or without jaundice) resolve within 1 to 2 months. However, HEV sometimes leads to acute liver failure, chronic infection, or extrahepatic symptoms. The mechanisms of pathogenesis appear to be substantially immune mediated. This review covers the epidemiology of HEV infection worldwide, the humoral and cellular immune responses to HEV, and the persistence and protection of antibodies produced in response to both natural infection and vaccines. We focus on the contributions of altered immune states (associated with pregnancy, human immunodeficiency virus [HIV], and immunosuppressive agents used in cancer and transplant medicine) to the elevated risks of chronic infection (in immunosuppressed/immunocompromised patients) and acute liver failure and mortality (among pregnant women). We conclude by discussing outstanding questions about the immune response to HEV and interactions with hormones and comorbid conditions. These questions take on heightened importance now that a vaccine is available.

Hepatitis E: An emerging infection in high income countries

Hepatitis E virus (HEV) genotype 3 is the most recently characterized hepatotropic virus and is increasingly being recognized as the cause of unexplained liver disease in many western countries. Although asymptomatic in most cases, HEV GT3 may be responsible for a wide range of illnesses, from mild to fulminant acute hepatitis, and also chronic hepatitis in immunocompromised patients. Extrahepatic manifestations have been occasionally described. Anti-HEV antibody detection by immunoassays is hampered by moderate test accuracy particularly in immunocompromised hosts while a WHO international standard for molecular detection of HEV RNA by RT-PCR has recently been introduced. This review describes the basic virology, epidemiology, clinical virology and treatment of HEV GT3 infections in high income countries.

Patients infected with HIV are at high-risk for hepatitis E virus infection in Spain

Hepatitis E virus is responsible for sporadic cases of acute, self-limited viral hepatitis not only in endemic but also in industrialized countries. In addition, some reports confirm that it can cause chronic infection and even cirrhosis in immunosuppressed and also in patients infected with HIV. There are few data about prevalence and incidence of HEV chronic infection in HIV-HEV coinfected individuals in Spain. The aim of this study is to investigate the prevalence of anti-HEV IgG in a representative sample of 448 patients infected with HIV and determine the role of age, gender, and CD4 counts in the detection of anti-HEV IgG antibodies in blood. In addition, the clinical features and ALT levels in relation to the presence of anti-HEV IgM and/or HEV-RNA in the blood of these patients were investigated. Anti-HEV IgG antibodies were detected in serum using a commercial enzyme immunoassay. All positive samples were studied further for the presence of anti-HEV IgM antibodies. In addition, HEV RNA was amplified by reverse transcriptase (RT)-nested PCR in all serum samples with IgM anti-HEV. The overall prevalence of anti-HEV IgG was 10.4% (45/448, 95% C.I. 7.2-12.8%). HEV-RNA was found in only one patient out of the 45 anti-HEV IgG positive samples studied. Regarding to gender and CD4 count, no difference in seroprevalence could be observed. This prevalence data suggest that patients infected with HIV can be considered a risk group for HEV infection and that chronic coinfection HEV-HIV seems to be a very rare event.

Seroepidemiology of hepatitis E virus infection in an urban population in Zambia: strong association with HIV and environmental enteropathy

Background. Hepatitis E virus (HEV) infection causes major epidemics of infectious hepatitis, with high mortality rates in pregnant women. Recent reports indicate that HEV coinfections with human immunodeficiency virus (HIV) may have a more protracted course. However, the impact of HEV infections in communities heavily affected by HIV remains poorly studied. We set out to examine age-related seroprevalence in a community where we have previously carried out studies on environmental enteropathy.

Methods. Blood samples from 194 children and 106 adults were examined for immunoglobulin G and immunoglobulin M antibodies for HEV. HEV data were correlated with HIV status and morphometric analysis of small intestinal biopsies.

Results. Seroprevalence rose throughout childhood, from 8% in children aged 1–4 years, to 36% in children aged 10–14 years. In adults, the overall prevalence was 42%, with 28% in HIV-seronegative adults and 71% in HIV-seropositive adults (odds ratio, 6.2; 95% confidence interval, 2.2–18; P = .0001). In adults, villous height and crypt depth measurements showed that HEV seropositivity was associated with worse enteropathy (P = .05 and P = .005, respectively).

Conclusions. HEV infection is common in Zambia. In adults it is strongly associated with HIV status, and also with environmental enteropathy.