Aetiology, clinical course and outcome of sporadic acute viral hepatitis in pregnancy

Pathogenesis of viral infections during pregnancy

SUMMARYViral infections during pregnancy are associated with significant adverse perinatal and fetal outcomes. Pregnancy is a unique immunologic and physiologic state, which can influence control of virus replication, severity of disease, and vertical transmission. The placenta is the organ of the maternal-fetal interface and provides defense against microbial infection while supporting the semi-allogeneic fetus via tolerogenic immune responses. Some viruses, such as cytomegalovirus, Zika virus, and rubella virus, can breach these defenses, directly infecting the fetus and having long-lasting consequences. Even without direct placental infection, other viruses, including respiratory viruses like influenza viruses and severe acute respiratory syndrome coronavirus 2, still cause placental damage and inflammation. Concentrations of progesterone and estrogens rise during pregnancy and contribute to immunological adaptations, placentation, and placental development and play a pivotal role in creating a tolerogenic environment at the maternal-fetal interface. Animal models, including mice, nonhuman primates, rabbits, and guinea pigs, are instrumental for mechanistic insights into the pathogenesis of viral infections during pregnancy and identification of targetable treatments to improve health outcomes of pregnant individuals and offspring.

Emerging Pathogens Causing Acute Hepatitis

Acute hepatitis is defined as an inflammation or injury in the hepatocytes that continues for a short period of time (less than 6 months) [...].

The hepatitis E virus ORF1 hypervariable region confers partial cyclophilin dependency

Hepatitis E virus (HEV) is an emerging pathogen responsible for more than 20 million cases of acute hepatitis globally per annum. Healthy individuals typically have a self-limiting infection, but mortality rates in some populations such as pregnant women can reach 30 %. A detailed understanding of the virus lifecycle is lacking, mainly due to limitations in experimental systems. In this regard, the cyclophilins are an important family of proteins that have peptidyl-prolyl isomerase activity and play roles in the replication of a number of positive-sense RNA viruses, including hepatotropic viruses such as hepatitis C virus (HCV). Cyclophilins A and B (CypA/B) are the two most abundant Cyps in hepatocytes and are therefore potential targets for pan-viral therapeutics. Here, we investigated the importance of CypA and CypB for HEV genome replication using sub-genomic replicons. Using a combination of pharmacological inhibition by cyclosporine A (CsA), and silencing by small hairpin RNA we find that CypA and CypB are not essential for HEV replication. However, we find that silencing of CypB reduces replication of some HEV isolates in some cells. Furthermore, sensitivity to Cyp silencing appears to be partly conferred by the sequence within the hypervariable region of the viral polyprotein. These data suggest HEV is atypical in its requirements for cyclophilin for viral genome replication and that this phenomenon could be genotype- and sequence-specific.

Diagnostic Approach to Elevated Liver Function Tests during Pregnancy: A Pragmatic Narrative Review

Liver disease is not uncommon during pregnancy and is associated with increased maternal and fetal/neonatal morbidity and mortality. Physiological changes during pregnancy, including a hyperestrogenic state, increase in circulating plasma volume and/or reduction in splanchnic vascular resistance, and hemostatic imbalance, may mimic or worsen liver disease. For the clinician, it is important to distinguish among the first presentation or exacerbation of chronic liver disease, acute liver disease non-specific to pregnancy, and pregnancy-specific liver disease. This last group classically includes conditions such as hyperemesis gravidarum, intrahepatic cholestasis of pregnancy, liver disorders associated with the pre-eclampsia spectrum, and an acute fatty liver of pregnancy. All of these disorders often share pathophysiological mechanisms, symptoms, and laboratory findings (such as elevated liver enzymes), but a prompt and correct diagnosis is fundamental to guide obstetric conduct, reduce morbidity and mortality, and inform upon the risk of recurrence or development of other chronic diseases later on in life. Finally, the cause of elevated liver enzymes during pregnancy is unclear in up to 30-40% of the cases, and yet, little is known on the causes and mechanisms underlying these alterations, or whether these findings are associated with worse maternal/fetal outcomes. In this narrative review, we aimed to summarize pragmatically the diagnostic work-up and the management of subjects with elevated liver enzymes during pregnancy.

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

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

Discovery of Hepatitis E and Its Impact on Global Health: A Journey of 44 Years about an Incredible Human-Interest Story

The story of the discovery of hepatitis E originated in the late 1970s with my extreme belief that there was a hidden saga in the relationship between jaundice and pregnancy in developing countries and the opportunity for a massive epidemic of viral hepatitis, which hit the Gulmarg Kashmir region in November 1978. Based on data collected from a door-to-door survey, the existence of a new disease, epidemic non-A, non-B hepatitis, caused by a hitherto unknown hepatitis virus, was announced. This news was received by the world community with hype and skepticism. In the early 1980s, the world watched in awe as an extreme example of human self-experimentation led to the identification of VLP. In 1990, a cDNA clone from the virus responsible for epidemic non-A, non-B hepatitis was isolated. Over the years, we traversed three eras of ambiguity, hope, and hype of hepatitis E research and conducted several seminal studies to understand the biology of HEV and manifestations of hepatitis E. Many milestones have been reached on the long and winding road of hepatitis E research to understand the structure, biology, and diversity of the agent, changing the behavior of the pathogen in developed countries, and the discovery of a highly effective vaccine.

The Re-Emergence of Hepatitis E Virus in Europe and Vaccine Development

Hepatitis E virus (HEV) is one of the leading causes of acute viral hepatitis. Transmission of HEV mainly occurs via the fecal-oral route (ingesting contaminated water or food) or by contact with infected animals and their raw meat products. Some animals, such as pigs, wild boars, sheep, goats, rabbits, camels, rats, etc., are natural reservoirs of HEV, which places people in close contact with them at increased risk of HEV disease. Although hepatitis E is a self-limiting infection, it could also lead to severe illness, particularly among pregnant women, or chronic infection in immunocompromised people. A growing number of studies point out that HEV can be classified as a re-emerging virus in developed countries. Preventative efforts are needed to reduce the incidence of acute and chronic hepatitis E in non-endemic and endemic countries. There is a recombinant HEV vaccine, but it is approved for use and commercially available only in China and Pakistan. However, further studies are needed to demonstrate the necessity of applying a preventive vaccine and to create conditions for reducing the spread of HEV. This review emphasizes the hepatitis E virus and its importance for public health in Europe, the methods of virus transmission and treatment, and summarizes the latest studies on HEV vaccine development.

Comparative Analysis on Clinical Characteristics Among Patients with Acute Hepatitis A Virus (HAV) and Patients with Acute Hepatitis E Virus (HEV): A Single-Center Retrospective Study from Bulgaria

Introduction

The acute viral hepatitis was one of the most common conditions in daily clinical practice varying in different parts of the world. The aim of the present study was to perform a comparative analysis on clinical characteristics among patients with acute hepatitis A virus (HAV) infection and patients with acute hepatitis E virus (HEV) infection admitted to the Military Medical Academy (MMA), Sofia, Bulgaria.

Methods

A retrospective study was performed at MMA, between 1 January 2016 and 31 December 2021. The etiological diagnosis was confirmed by enzyme-linked immunosorbent assay (ELISA) HAV/HEV IgM serology assays.

Results

The current survey included 231 patients with mean age 45.11 ± 16.08 years (95% confidence interval: 43.04-47.19). According to the case definition, inclusion and exclusion criteria, persons were divided into two groups: patients with acute HAV infection (68.4%; 158/231) and patients with acute HEV infection (31.6%; 73/231). Males with HEV had 3.091 times the odds of comorbidity "hypertension" than males with HAV (p = 0.032). There were almost equal odds of increased ALT (odds ratio = 0.999; p = 0.003) in men with HEV and men with HAV. Females with HEV had 5.161 times the odds of comorbidity "hypertension" compared with females with HAV (p = 0.049). We found almost equal odds for elevated ALT in women with HEV and women with HAV (OR = 0.999; p = 0.025). In the non-elderly group (<60-year-old), HEV individuals had 4.544 and 10.560 times the odds of comorbidities "hypertension" and "cardiovascular diseases" compared with HAV patients (p < 0.05). We found almost equal odds for elevated ALT in HEV patients and HAV participants (OR = 0.998; p = 0.002).

Conclusion

The results from the current study may support the physicians daily care for patients with acute HAV and acute HEV.

Fetal Loss in Pregnant Rabbits Infected with Genotype 3 Hepatitis E Virus Is Associated with Altered Inflammatory Responses, Enhanced Virus Replication, and Extrahepatic Virus Dissemination with Positive Correlations with Increased Estradiol Level

Hepatitis E virus (HEV) causes adverse clinical outcomes in pregnant women, but the underlying mechanisms remain poorly understood. To delineate the mechanisms of pregnancy-associated adverse effects during HEV infection, we utilized a genotype 3 HEV from rabbit (HEV-3ra) and its cognate host (rabbits) to systematically investigate the clinical consequences, viral replication dynamics, and host immune and hormonal responses of HEV infection during pregnancy. We found a significant fetal loss of 23% in HEV-infected pregnant rabbits, indicating an early-stage miscarriage. HEV infection in pregnant rabbits was characterized by higher viral loads in feces, intestinal contents, liver, and spleen tissues, as well as a longer and earlier onset of viremia than in infected nonpregnant rabbits. HEV infection altered the pattern of cytokine gene expressions in the liver of pregnant rabbits and caused a transient increase of serum interferon gamma (IFN-γ) shortly after a notable increase in viral replication, which may contribute to early fetal loss. Histological lesions in the spleen were more pronounced in infected pregnant rabbits, although moderate liver lesions were seen in both infected pregnant and nonpregnant rabbits. Total bilirubin was elevated in infected pregnant rabbits. The serum levels of estradiol (E2) in HEV-infected pregnant rabbits were significantly higher than those in mock-infected pregnant rabbits at 14 days postinoculation (dpi) and correlated positively with higher viral loads in feces, liver, and spleen tissues at 28 dpi, suggesting that it may play a role in extrahepatic virus dissemination. The results have important implications for understanding the severe diseases associated with HEV infection during pregnancy. IMPORTANCE HEV causes adverse pregnancy outcomes, with a mortality rate of >30% in pregnant women, but the underlying mechanisms are poorly understood. In this study, we utilized HEV-3ra and its cognate host (pregnant rabbit) to delineate the potential underlying mechanisms of pregnancy-associated adverse outcomes during HEV infection. We found that infected pregnant rabbits had a fetal loss of 23%, which coincided with enhanced viral replication and an elevated systemic IFN-γ response, followed by longer viremia duration and extrahepatic viral dissemination. Estradiol levels were increased in infected pregnant rabbits and correlated positively with higher fecal viral shedding and higher viral loads in liver and spleen tissues. Infected pregnant rabbits had more pronounced splenic lesions, higher serum total bilirubin, and an altered cytokine gene expression profile in the liver. The results will contribute to our understanding of the mechanisms of HEV-associated adverse pregnancy outcomes.

Severe hepatitis E infection in pregnancy: a case report

Hepatitis E virus causes self limiting hepatitis most of the times but, during pregnancy it can lead to severe hepatitis along with various complications thereby increasing the mortality.

Case presentation

A 27-year-old woman gravida two, para one at 38 weeks and 6 days of gestation presented with multiple episodes of nonbilious vomiting, severe dehydration, and later developed right upper quadrant abdominal pain. The patient had a positive serological test for the hepatitis E virus, and liver enzymes were severely elevated. Under supportive treatment she delivered a healthy baby, and her liver enzymes returned to normal levels after 2 weeks of delivery.

Clinical discussion

Although the hepatitis E virus usually causes self-limiting hepatitis, it can quickly progress to severe hepatitis, liver failure, and even death during pregnancy. Immunological change with a Th2 biased response and increased hormonal levels during pregnancy could possibly facilitate the development of severe liver damage. No particular drug has been approved for the treatment of hepatitis E viral infection in pregnant women, and the commonly used drugs are contraindicated due to the risk of teratogenicity. Supportive therapy and intensive monitoring are the core management techniques for hepatitis E virus infection in pregnant women.

Conclusion

Due to the high mortality risk, pregnant women should try to avoid possible exposure to the hepatitis E virus, but once infected, symptomatic therapy is the mainstay.

A case of persistent hepatitis E virus infection in a young adult with no medical history

Most patients with hepatitis E virus (HEV) infection are asymptomatic and improve naturally without any treatment, but even non-immunocompromised individuals may develop persistent HEV infections and should be monitored regularly for the onset.

Structural features stabilized by divalent cation coordination within hepatitis E virus ORF1 are critical for viral replication

Hepatitis E virus (HEV) is an RNA virus responsible for over 20 million infections annually. HEV's open reading frame (ORF)1 polyprotein is essential for genome replication, though it is unknown how the different subdomains function within a structural context. Our data show that ORF1 operates as a multifunctional protein, which is not subject to proteolytic processing. Supporting this model, scanning mutagenesis performed on the putative papain-like cysteine protease (pPCP) domain revealed six cysteines essential for viral replication. Our data are consistent with their role in divalent metal ion coordination, which governs local and interdomain interactions that are critical for the overall structure of ORF1; furthermore, the 'pPCP' domain can only rescue viral genome replication in trans when expressed in the context of the full-length ORF1 protein but not as an individual subdomain. Taken together, our work provides a comprehensive model of the structure and function of HEV ORF1.

Severe maternal-fetal pathological damage and inflammatory responses contribute to miscarriage caused by hepatitis E viral infection during pregnancy

BACKGROUND

Hepatitis E virus (HEV) infection causes serious adverse pregnancy outcomes during pregnancy. However, the maternal and fetal damage induced by HEV infection is rarely reported.

METHODS

A BALB/c pregnant mouse model was established to explore the maternal and fetal pathological damage and inflammatory responses caused by HEV infection.

RESULTS

Notably, miscarriages and stillbirths were observed in HEV-infected pregnant mice. HEV infections were identified by qRT-PCR, immunohistochemical analysis and immunofluorescence assay in the uterus, placenta, umbilical cords and livers and brains of fetuses. Serious inflammatory responses and pathological damage were triggered in the uterus and placenta of HEV-infected pregnant mice. Vertical transmission of HEV resulted in severe pathological damage and inflammatory responses in the livers and brains of fetuses, as well as emerging apoptosis cells in the brains of fetuses. Most of the cytokines/chemokines in the sera were significantly increased in the HEV-infected pregnant mice. Remarkably, cytokines/chemokines were significantly different between HEV-infected pregnant and miscarriage mice; IL9, GM-CSF and IL1α were the most important three cytokines/chemokines in determining the pregnancy outcomes.

CONCLUSION

HEV infections cause serious maternal/fetal pathological damage, inflammatory responses and apoptosis, which may be responsible for adverse pregnancy outcomes.

Transmission of Hepatitis E Virus

Transmission of hepatitis E virus (HEV) occurs predominantly by the fecal-oral route. Large epidemics of hepatitis E in the developing countries of Asia and Africa are waterborne and spread through contaminated drinking water. The reservoir of HEV in developed countries is believed to be in animals with zoonotic transmission to humans, possibly through direct contact or the consumption of undercooked contaminated meat. And HEV transmission through blood transfusion, organ transplantation, and vertical transmission has been reported.

Low mortality despite temporary liver dysfunction in severe courses of acute hepatitis E

BACKGROUND

Hepatitis E virus (HEV) infection can cause severe viral hepatitis and eventually liver failure. We aim to provide novel data on the epidemiology and the course of HEV infections from Q1/2008 to Q3/2018 at the Vienna General Hospital.

METHODS

Of the 88,945 people tested, we identified HEV-IgM positive (+) or HEV-PCR (+) patients and retrospectively collated information on the course of infection from patient records.

RESULTS

Among 151 HEV-IgM or PCR (+) (median age 51 years, 45.8% female), 7 (4.6%) had non-severe acute HEV infection (ALT ≥ 2-5-fold upper limit of normal, ULN), 11 (7.3%) had severe HEV infection without liver dysfunction (LD) (ALT > 5-fold ULN), and 9 (6.0%) with LD (ikterus or bilirubin > 5 mg/dL, OR coagulopathy or INR > 1.5, OR encephalopathy or ammonia > 100 µmol/L). HEV-RNA-PCR was performed in 58/190 (30.5%) HEV-IgM (+) patients and was positive in 19 (30.6%). Rates of HEV IgM/PCR positivity remained stable over the observation period. The HEV genotype (GT) was GT‑1 in 71.4% (n = 5) and GT‑3 in 28.6% (n = 2). Travel history was recorded for 9/20 (45.0%) of severe HEV and 12/20 (60.0%) patients with severe HEV infection were hospitalized. One patient with pre-existing liver disease and concomitant EBV infection required intensive care. No patient required transplantation and the 30-day mortality was 3/151 (1.9%). Despite the increased testing rates, the absolute number of diagnosed HEV infections at Vienna General Hospital remained constant between 2008 to 2018.

CONCLUSION

Although approximately half of the patients with severe acute HEV infection required hospitalization, admissions to the intensive care unit (ICU) and short-term mortality were low.

Prevalence of hepatitis E virus and its association with adverse pregnancy outcomes in pregnant women in China

BACKGROUND

Hepatitis E virus (HEV) infection has become a global concern, especially in pregnant women. However, the association between HEV prevalence and age, gravidity and parity of pregnant women remains unclear.

METHODS

Pregnant women (n=19,762) were enrolled for HEV prevalence and associated adverse pregnancy outcomes investigation in Qujing City, Yunnan Province of China from May 2019 to December 2020.

RESULTS

The seroprevalence of HEV was 11.6% (2,297/19,762; 95% CI:11.2%-12.1%). About 11.4% (2,247/19,762; 95% CI:10.9%-11.8%) were positive for anti-HEV IgG antibody, 0.1% (22/19,762; 95% CI:0.1%-0.2%) were positive for anti-HEV IgM antibody, and 0.1% (28/19,762; 95% CI:0.1%-0.2%) were positive for both anti-HEV IgM and IgG antibodies. Sixty-one out of 2,297 anti-HEV-antibodies-positive pregnant women were positive for HEV RNA. Phylogenetic analysis revealed that all HEV isolates from pregnant women belong to genotype 4. Age, gravidity and parity are associated with increased prevalence of HEV. Pregnant women positive for HEV-IgG antibody bear a higher risk for an adverse pregnancy history and liver injury with elevated alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels than anti-HEV-negative pregnant women. Furthermore, seropositive pregnant women suffered a higher adverse maternal outcomes risk (crude odds ratio [cOR]=1.29; 95% CI: 1.16-1.43; adjusted odds ratio [aOR]=1.40, 95% CI: 1.25-1.55 for anti-HEV-IgG-positive pregnant women and cOR=1.38, 95% CI: 1.02-1.86; aOR=1.43, 95% CI: 1.05-1.95 for anti-HEV-IgM-positive pregnant women) and fetal outcomes risk (cOR=1.80, 95% CI: 1.61-2.01; aOR=1.77, 95% CI: 1.57-1.99) than anti-HEV-negative pregnant women. Adverse pregnancy outcomes of HEV infection are aggravated by age, gravidity and parity.

CONCLUSION

In this study, we demonstrated high prevalence of HEV in pregnancy women in China, and HEV infection can cause various adverse maternal and neonatal outcomes.

Viral hepatitis in pregnancy

Viral hepatitis is caused by a heterogenous group of viral agents representing a wide range of phylogenetic groups. Many viruses can involve the liver and cause liver injury but only a subset are delineated as 'hepatitis viruses' based upon their primary site of replication and tropism for hepatocytes which make up the bulk of the liver cell population. Since their discovery, beginning with the agent that caused serum hepatitis in the 1960s, the alphabetic designations have been utilized. To date, we have five hepatitis viruses, A through E, though it is postulated that others may exist. This chapter will focus on those viruses. Note that hepatitis D is included as a subset of hepatitis B, as it cannot exist without concurrent hepatitis B infection. Pregnancy has the potential to affect all aspects of these viral agents due to the unique immunologic and physiologic changes that occur during and after the gestational period. In this review, we will discuss the most common viral hepatitis and their effects during pregnancy.

Urine is a viral antigen reservoir in hepatitis E virus infection

BACKGROUND AND AIMS

HEV ORF2 antigen (Ag) in serum has become a tool for diagnosing current HEV infection. Particularly, urinary shedding of HEV Ag has been gaining increasing interest. We aim to uncover the origin, antigenicity, diagnostic performance, and diagnostic significance of Ag in urine in HEV infection.

APPROACH AND RESULTS

Clinical serum and urine samples from patients with acute and chronic HEV infection were analyzed for their Ag levels. Ag in urine was analyzed by biochemical and proteomic approaches. The origin of urinary Ag and Ag kinetics during HEV infection was investigated in mouse and rabbit models, respectively. We found that both the Ag level and diagnostic sensitivity in urine were higher than in serum. Antigenic protein in urine was an E2s-like dimer spanning amino acids 453-606. pORF2 entered urine from serum in mice i.v. injected with pORF2. Ag in urine originated from the secreted form of pORF2 (ORF2^S ) that abundantly existed in hepatitis E patients' serum. HEV Ag was specifically taken up by renal cells and was disposed into urine, during which the level of Ag was concentrated >10-fold, resulting in the higher diagnosing sensitivity of urine Ag than serum Ag. Moreover, Ag in urine appeared 6 days earlier, lasted longer than viremia and antigenemia, and showed good concordance with fecal RNA in a rabbit model.

CONCLUSIONS

Our findings demonstrated the origin and diagnostic value of urine Ag and provided insights into the disposal of exogenous protein of pathogens by the host kidney.

Global public health implications of human exposure to viral contaminated water

Enteric viruses are common waterborne pathogens found in environmental water bodies contaminated with either raw or partially treated sewage discharge. Examples of these viruses include adenovirus, rotavirus, noroviruses, and other caliciviruses and enteroviruses like coxsackievirus and polioviruses. They have been linked with gastroenteritis, while some enteric viruses have also been implicated in more severe infections such as encephalitis, meningitis, hepatitis (hepatitis A and E viruses), cancer (polyomavirus), and myocarditis (enteroviruses). Therefore, this review presents information on the occurrence of enteric viruses of public health importance, diseases associated with human exposure to enteric viruses, assessment of their presence in contaminated water, and their removal in water and wastewater sources. In order to prevent illnesses associated with human exposure to viral contaminated water, we suggest the regular viral monitoring of treated wastewater before discharging it into the environment. Furthermore, we highlight the need for more research to focus on the development of more holistic disinfection methods that will inactivate waterborne viruses in municipal wastewater discharges, as this is highly needed to curtail the public health effects of human exposure to contaminated water. Moreover, such a method must be devoid of disinfection by-products that have mutagenic and carcinogenic potential.

A ribavirin-induced ORF2 single-nucleotide variant produces defective hepatitis E virus particles with immune decoy function

Hepatitis E virus (HEV) has increasing prevalence worldwide. However, little is known about the impact of single-nucleotide variants (SNV) on the replication cycle. Here, we report a ribavirin-induced open reading frame 2 (ORF2) SNV that demonstrats reduced RNA copies released in the supernatant and an impairment in the production of infectious particles. Furthermore, the P79S variant displays an altered subcellular distribution of the ORF2 protein and is able to impair antibody-mediated neutralization of HEV in a competition assay potentially acting as an immune decoy. These findings provide insights in understanding the biology of circulating HEV variants and may guide development of personalized antiviral strategies in the future.

Hepatitis E virus (HEV) is the causative agent of hepatitis E in humans and is the leading cause of enterically transmitted viral hepatitis worldwide. Ribavirin (RBV) is currently the only treatment option for many patients; however, cases of treatment failures or posttreatment relapses have been frequently reported. RBV therapy was shown to be associated with an increase in HEV genome heterogeneity and the emergence of distinct HEV variants. In this study, we analyzed the impact of eight patient-derived open reading frame 2 (ORF2) single-nucleotide variants (SNVs), which occurred under RBV treatment, on the replication cycle and pathogenesis of HEV. The parental HEV strain and seven ORF2 variants showed comparable levels of RNA replication in human hepatoma cells and primary human hepatocytes. However, a P79S ORF2 variant demonstrated reduced RNA copy numbers released in the supernatant and an impairment in the production of infectious particles. Biophysical and biochemical characterization revealed that this SNV caused defective, smaller HEV particles with a loss of infectiousness. Furthermore, the P79S variant displayed an altered subcellular distribution of the ORF2 protein and was able to interfere with antibody-mediated neutralization of HEV in a competition assay. In conclusion, an SNV in the HEV ORF2 could be identified that resulted in altered virus particles that were noninfectious in vitro and in vivo, but could potentially serve as immune decoys. These findings provide insights in understanding the biology of circulating HEV variants and may guide development of personalized antiviral strategies in the future.

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.

Pigs Immunized with the Virus-like Particle Vaccine Are Protected against the Hepatitis E-3 Virus

In this study, we generated the HEV virus-like particle (VLP) vaccine expressing 239 amino acids (367–605 aa) of the HEV-3 ORF2 using the baculovirus expression system. The HEV-3-239-VLP vaccine efficacy was evaluated by dividing 12 pathogen-free pigs into four groups: negative control, positive control, 100 μg VLP-, and 200 μg VLP-vaccinated groups for 10 weeks. The pigs in either of the vaccinated groups were administered the corresponding first and booster doses on weeks 0 and 2. At week 4, the positive control and two vaccinated groups were challenged with 10⁶ HEV-3 genomic equivalent copies; viremia and fecal shedding of the virus were identified in pigs in the positive control and 100 μg VLP-vaccinated pigs showed transient viremia and fecal viral shedding. However, no viruses were detected in the serum or fecal samples of the 200 μg VLP-vaccinated pigs. The 100 and 200 μg VLP-vaccinated pigs had significantly higher (p < 0.01) anti-HEV antibodies than the negative control pigs from weeks 6–10 with normal levels of liver enzymes. The 200 μg VLP-vaccinated pigs showed statistically less liver tissue fibrosis (p < 0.05) than that of the positive control pigs. Thus, the novel baculovirus expression system-generated VLP vaccine dose-dependently protects against HEV-3 challenge and may be useful in other animal species, including humans.

Role of "dual-personality" fragments in HEV adaptation-analysis of Y-domain region

BACKGROUND

Hepatitis E is a liver disease caused by the pathogen hepatitis E virus (HEV). The largest polyprotein open reading frame 1 (ORF1) contains a nonstructural Y-domain region (YDR) whose activity in HEV adaptation remains uncharted. The specific role of disordered regions in several nonstructural proteins has been demonstrated to participate in the multiplication and multiple regulatory functions of the viruses. Thus, intrinsic disorder of YDR including its structural and functional annotation was comprehensively studied by exploiting computational methodologies to delineate its role in viral adaptation.

RESULTS

Based on our findings, it was evident that YDR contains significantly higher levels of ordered regions with less prevalence of disordered residues. Sequence-based analysis of YDR revealed it as a "dual personality" (DP) protein due to the presence of both structured and unstructured (intrinsically disordered) regions. The evolution of YDR was shaped by pressures that lead towards predominance of both disordered and regularly folded amino acids (Ala, Arg, Gly, Ile, Leu, Phe, Pro, Ser, Tyr, Val). Additionally, the predominance of characteristic DP residues (Thr, Arg, Gly, and Pro) further showed the order as well as disorder characteristic possessed by YDR. The intrinsic disorder propensity analysis of YDR revealed it as a moderately disordered protein. All the YDR sequences consisted of molecular recognition features (MoRFs), i.e., intrinsic disorder-based protein-protein interaction (PPI) sites, in addition to several nucleotide-binding sites. Thus, the presence of molecular recognition (PPI, RNA binding, and DNA binding) signifies the YDR's interaction with specific partners, host membranes leading to further viral infection. The presence of various disordered-based phosphorylation sites further signifies the role of YDR in various biological processes. Furthermore, functional annotation of YDR revealed it as a multifunctional-associated protein, due to its susceptibility in binding to a wide range of ligands and involvement in various catalytic activities.

CONCLUSIONS

As DP are targets for regulation, thus, YDR contributes to cellular signaling processes through PPIs. As YDR is incompletely understood, therefore, our data on disorder-based function could help in better understanding its associated functions. Collectively, our novel data from this comprehensive investigation is the first attempt to delineate YDR role in the regulation and pathogenesis of HEV.

Hepatitis E and Pregnancy: An Unholy Alliance Unmasked from Kashmir, India

The adverse relationship between viral hepatitis and pregnancy in developing countries had been interpreted as a reflection of retrospectively biased hospital-based data collection by the West. However, the discovery of hepatitis E virus (HEV) as the etiological agent of an epidemic of non-A, non-B hepatitis in Kashmir, and the documenting of the increased incidence and severity of hepatitis E in pregnancy via a house-to-house survey, unmasked this unholy alliance. In the Hepeviridae family, HEV-genotype (gt)1 from genus Orthohepevirus A has a unique open reading frame (ORF)4-encoded protein which enhances viral polymerase activity and viral replication. The epidemics caused by HEV-gt1, but not any other Orthohepevirus A genotype, show an adverse relationship with pregnancy in humans. The pathogenesis of the association is complex and at present not well understood. Possibly multiple factors play a role in causing severe liver disease in the pregnant women including infection and damage to the maternal-fetal interface by HEV-gt1; vertical transmission of HEV to fetus causing severe fetal/neonatal hepatitis; and combined viral and hormone related immune dysfunction of diverse nature in the pregnant women, promoting viral replication. Management is multidisciplinary and needs a close watch for the development and management of acute liver failure. (ALF). Preliminary data suggest beneficial maternal outcomes by early termination of pregnancy in patients with lower grades of encephalopathy.

Feasibility of controlling hepatitis E in Jiangsu Province, China: a modelling study

BACKGROUND

Hepatitis E, an acute zoonotic disease caused by the hepatitis E virus (HEV), has a relatively high burden in developing countries. The current research model on hepatitis E mainly uses experimental animal models (such as pigs, chickens, and rabbits) to explain the transmission of HEV. Few studies have developed a multi-host and multi-route transmission dynamic model (MHMRTDM) to explore the transmission feature of HEV. Hence, this study aimed to explore its transmission and evaluate the effectiveness of intervention using the dataset of Jiangsu Province.

METHODS

We developed a dataset comprising all reported HEV cases in Jiangsu Province from 2005 to 2018. The MHMRTDM was developed according to the natural history of HEV cases among humans and pigs and the multi-transmission routes such as person-to-person, pig-to-person, and environment-to-person. We estimated the key parameter of the transmission using the principle of least root mean square to fit the curve of the MHMRTDM to the reported data. We developed models with single or combined countermeasures to assess the effectiveness of interventions, which include vaccination, shortening the infectious period, and cutting transmission routes. The indicator, total attack rate (TAR), was adopted to assess the effectiveness.

RESULTS

From 2005 to 2018, 44 923 hepatitis E cases were reported in Jiangsu Province. The model fits the data well (R2 = 0.655, P < 0.001). The incidence of the disease in Jiangsu Province and its cities peaks are around March; however, transmissibility of the disease peaks in December and January. The model showed that the most effective intervention was interrupting the pig-to-person route during the incidence trough of September, thereby reducing the TAR by 98.11%, followed by vaccination (reducing the TAR by 76.25% when the vaccination coefficient is 100%) and shortening the infectious period (reducing the TAR by 50.05% when the infectious period is shortened to 15 days).

CONCLUSIONS

HEV could be controlled by interrupting the pig-to-person route, shortening the infectious period, and vaccination. Among these interventions, the most effective was interrupting the pig-to-person route.

Hepatitis E Virus in Croatia in the "One-Health" Context

Hepatitis E virus (HEV) is the most common cause of viral hepatitis globally. The first human case of autochthonous HEV infection in Croatia was reported in 2012, with the undefined zoonotic transmission of HEV genotype 3. This narrative review comprehensively addresses the current knowledge on the HEV epidemiology in humans and animals in Croatia. Published studies showed the presence of HEV antibodies in different population groups, such as chronic patients, healthcare professionals, voluntary blood donors and professionally exposed and pregnant women. The highest seroprevalence in humans was found in patients on hemodialysis in a study conducted in 2018 (27.9%). Apart from humans, different studies have confirmed the infection in pigs, wild boars and a mouse, indicating the interspecies transmission of HEV due to direct or indirect contact or as a foodborne infection. Continued periodical surveys in humans and animals are needed to identify the possible changes in the epidemiology of HEV infections.

The different replication between nonenveloped and quasi-enveloped hepatitis E virus

Hepatitis E virus (HEV) is the major pathogen of viral hepatitis. However, the understanding of the HEV life cycle is limited. In the present study, cells were separately infected with nonenveloped HEV (derived from feces or bile) or quasi-enveloped HEV (derived from the cell culture after serial passages, eHEV) and observed by confocal fluorescence microscopy to investigate the life cycle of HEV. HEV finished its binding and entry into host cells at first 6 h postinoculation (hpi). Cells inoculated with eHEV showed less infectivity than cells inoculated with nonenveloped HEV. Newly synthesized progeny virions were released into the supernatant of cell cultures from 48 hpi. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analysis results showed that the supernatant's progeny viruses were infectious even after five serial passages. These results show the significant difference between nonenveloped HEV and eHEV, which will provide novel insights into the HEV replication cycle. The efficient cell culture of HEV will promote the development of anti-HEV drugs and vaccines.

Clinicobiochemical Parameters and Predictors of Liver Disease in Hospitalized Asian Indian Pregnant Women in a Tertiary Care Center in Northern India

Introduction  During pregnancy, liver dysfunction is more frequent than expected and may require specialized care. For the early diagnosis, it is important to determine if changes in liver physiology may develop into liver disease. Liver disease during pregnancy may require intervention from a hepatologist for adequate monitoring of mother-fetus health outcomes. This study was aimed to evaluate the clinical profile and predictors of maternal mortality in patients with liver diseases among Asian-Indian-females. Methods We conducted a prospective, open-label, consecutive all-comers study of 2,663 pregnant Asian Indian women admitted in the hospital, which included 92 with liver dysfunction. The medical aspects of the pregnancy were then followed prospectively with laboratory and clinical data during the hospital stay and analyzed. The current study was approved by the Institutional Ethical Committee. Results We found that 92 out of 2,663 patients had liver dysfunction with a prevalence of 3.45%. Fifty-four (58.7%) patients had icterus followed by fever in 23 (25.0%), hypertension in 22 (23.9%), central nervous system manifestations in 21 (22.8%), abdominal pain in 19 (20.6%), vomiting in 19 (20.6%), and pruritus in six (6.5%). Predictors of maternal mortality were icterus (p = 0.04), hepatomegaly (p = 0.04), presenting serum-bilirubin greater than 10 milligram% (mg%) (p = 0.008). The most common etiology was acute viral hepatitis (45.6%), followed by a hypertensive disorder of pregnancy (29.3%), acute fatty liver of pregnancy (1.1%), cholestatic jaundice (9.8%), hyperemesis gravidarum (2.2%), septicemic hepatitis (3.3%), dengue immunoglobulin M (IgM), and plasmodium vivax malaria antigen positive in (2.2%) each. Four patients (4.3%) were leptospira IgM reactive and had co-infection with hepatitis E virus. There was one patient (1.1%) with underlying chronic liver disease. Idiopathic liver disease was present in 5.4% of patients. Conclusion Liver disease is relatively common in Indian pregnant women. It is associated with high maternal and perinatal mortality, even in a tertiary referral center. When managing pregnancy in a tertiary care center, for adequate follow-up of the disease and to prevent adverse consequences for mother and child, it is important to discard liver alterations early. For this purpose, liver disease during pregnancy needs early diagnosis for proper management. Furthermore, it is difficult to manage patients with preexisting liver disease, and it may require specialized intervention from a hepatologist and a gastroenterologist.

Viral hepatitis and pregnancy

The management of viral hepatitis in the setting of pregnancy requires special consideration. There are five liver-specific viruses (hepatitis A, B, C, D, E), each with unique epidemiology, tendency to chronicity, risk of liver complications and response to antiviral therapies. In the setting of pregnancy, the liver health of the mother, the influence of pregnancy on the clinical course of the viral infection and the effect of the virus or liver disease on the developing infant must be considered. Although all hepatitis viruses can harm the mother and the child, the greatest risk to maternal health and subsequently the fetus is seen with acute hepatitis A virus or hepatitis E virus infection during pregnancy. By contrast, the primary risks for hepatitis B virus (HBV), hepatitis C virus (HCV) and hepatitis D virus are related to the severity of the underlying liver disease in the mother and the risk of mother-to-child transmission (MTCT) for HBV and HCV. The prevention of MTCT is key to reducing the global burden of chronic viral hepatitis, and prevention strategies must take into consideration local health-care and socioeconomic challenges. This Review presents the epidemiology of acute and chronic viral hepatitis infection in pregnancy, the effect of pregnancy on the course of viral infection and, conversely, the influence of the viral infection on maternal and infant outcomes, including MTCT.

Current Paradigm of Hepatitis E Virus Among Pediatric and Adult Patients

Hepatitis E virus (HEV) infection is a polymorphic condition, present throughout the world and involving children and adults. Multiple studies over the last decade have contributed to a better understanding of the natural evolution of this infection in various population groups, several reservoirs and transmission routes being identified. To date, acute or chronic HEV-induced hepatitis has in some cases remained underdiagnosed due to the lower accuracy of serological tests and due to the evolutionary possibility with extrahepatic manifestations. Implementation of diagnostic tests based on nucleic acid analysis has increased the detection rate of this disease. The epidemiological and clinical features of HEV hepatitis differ depending on the geographical areas studied. HEV infection is usually a self-limiting condition in immunocompetent patients, but in certain categories of vulnerable patients it can induce a sudden evolution toward acute liver failure (pregnant women) or chronicity (immunosuppressed patients, post-transplant, hematological, or malignant diseases). In acute HEV infections in most cases supportive treatment is sufficient. In patients who develop chronic hepatitis with HEV, dose reduction of immunosuppressive medication should be the first therapeutic step, especially in patients with transplant. In case of unfavorable response, the initiation of antiviral therapy is recommended. In this review, the authors summarized the essential published data related to the epidemiological, clinical, paraclinical, and therapeutic aspects of HEV infection in adult and pediatric patients.

Hepatitis E Virus Infection among Asymptomatic Pregnant Women at the University College Hospital, Ibadan

Introduction:

The high mortality associated with fulminant Hepatitis E infection in pregnancy justifies the need to assess the epidemiologic proportion of this underestimated virus.

Objectives:

This study aimed to determine the burden of HEV infection among pregnant women attending antenatal Clinic in Ibadan.

Methodology:

HEV IgG and IgM serological surveys were carried out among 230 pregnant women attending antenatal clinic in Ibadan, Nigeria. Serum and stool samples from HEV IgM positive women were further analysed using two independent reverse transcriptase polymerase chain reactions (RT-PCR) assays, targeting ORF1 region of HEV genome. Socio-demographic variables associated with HEV in these women, were analyzed to estimate statistical significance (P < 0.05).

Results:

Eleven (4.8%) women had HEV IgM, while 39 (17.0%) women had HEV IgG. Three (27.3%) of the 11 anti-HEV IgM positive samples were positive for HEV RNA while all stool samples tested negative for HEV RNA. HEV infection among pregnant women was statistically associated with age (p = 0.044), and educational status (p = 0.005).

Conclnusion:

Recent HEV infection among this pregnant population is on the lower part of the scale, compared with other Sub-Saharan African countries. However, the HEV IgG seroprevalence rate suggests indirect evidence of past contact with HEV.

Progress in the Production of Virus-Like Particles for Vaccination against Hepatitis E Virus

Hepatitis E virus (HEV), a pathogen that causes acute viral hepatitis, is a small icosahedral, quasi-enveloped, positive ssRNA virus. Its genome has three open reading frames (ORFs), with ORF1 and ORF3 encoding for nonstructural and regulatory proteins, respectively, while ORF2 is translated into the structural, capsid protein. ORF2 is most widely used for vaccine development in viral hepatitis. Hepatitis E virus-like particles (VLPs) are potential vaccine candidates against HEV infection. VLPs are composed of capsid subunits mimicking the natural configuration of the native virus but lack the genetic material needed for replication. As a result, VLPs are unable to replicate and cause disease, constituting safe vaccine platforms. Currently, the recombinant VLP-based vaccine Hecolin^® against HEV is only licensed in China. Herein, systematic information about the expression of various HEV ORF2 sequences and their ability to form VLPs in different systems is provided.

Burden of hepatitis E virus infection in pregnancy and maternofoetal outcomes: a systematic review and meta-analysis

Background

There is still a dearth of knowledge on the burden of HEV infection in the global population of pregnant women. Therefore, we conducted a systematic review and meta-analysis to estimate the global burden of HEV infection in pregnancy.

Methods

We searched PubMed, Embase, Web of Knowledge, and Global Index Medicus to identify articles published until January 26, 2020. We considered cross-sectional, case-control, and cohort studies reporting the immunoglobulins M HEV seroprevalence in asymptomatic and symptomatic (jaundice or elevated transaminases) pregnant women or investigating the association between HEV infection and maternofoetal outcomes. We used a random-effects model to pool studies. This review was registered with PROSPERO, CRD42018093820.

Results

For HEV prevalence estimates, we included 52 studies (11,663 pregnant women). The seroprevalence was 3.5% (95% confidence interval: 1.4–6.4) in asymptomatic women (most of whom from high endemic areas). The prevalence in symptomatic women was 49.6% (42.6–56.7) with data only from HEV high endemic countries. In the multivariable meta-regression model, the prevalence was higher in symptomatic women compared to asymptomatic (adjusted prevalence odds ratio [aPOR]: 1.76; 95%CI: 1.61–1.91) and decreased with increasing year of publication (by 10-year) (aPOR: 0.90; 95%CI: 0.84–0.96). The proportion of HEV vertical transmission was 36.9% (13.3–64.2). Risk of bias was low, moderate and high respectively in 12 (23%), 37 (70%), and 4 studies (7%) addressing HEV prevalence estimation. HEV infection was associated with maternal deaths (pooled OR 7.17; 3.32–15.47), low birth weight (OR: 3.23; 1.71–6.10), small for gestational age (OR: 3.63; 1.25–10.49), preterm < 32 weeks (OR: 4.18; 1.23–14.20), and preterm < 37 weeks (OR: 3.45; 2.32–5.13), stillbirth (OR: 2.61; 1.64–4.14), intrauterine deaths (OR: 3.07; 2.13–4.43), and not with miscarriage (OR: 1.74; 0.77–3.90). All studies which assessed the association between HEV infection and maternofoetal outcomes had a moderate risk of bias.

Conclusions

Findings from this study are suggestive of a high burden of HEV infection in pregnancy in high endemic countries, its association with poor maternofoetal outcomes, and a high rate of vertical transmission. This study supports the need for specific strategies to prevent exposure of pregnant women to HEV infection, especially in high endemic areas.

A Review of the Diagnosis and Management of Hepatitis E

Purpose of review

We aim to provide the readers an up-to-date knowledge of the structure, epidemiology, and transmission followed by a detailed discussion on testing, diagnostics and management of hepatitis E virus infection. We have also included a comprehensive review of hepatitis E in pregnancy.

Recent findings

European Association for the Study of the Liver established clinical practice guidelines for testing and treatment of suspected hepatitis E virus infections in 2018. Evidence suggests chronic hepatitis E may follow a course similar to hepatitis B/C with progression to cirrhosis and possibly hepatocellular carcinoma in immunocompromised patients.

Summary

Hepatitis E virus is the most common cause of acute viral hepatitis worldwide. A combination of serology and nucleic acid amplification testing is the recommended strategy for suspected patients. Ribavirin therapy for a period of 3 months is the drug of choice for severe acute hepatitis, acute-on chronic liver failure, and chronic infections from hepatitis E virus in immunocompromised patients who are unresponsive to decreased immunosuppression. PEGylated interferon α can be used for ribavirin-resistant liver transplant patients with chronic hepatitis E. Further research in therapeutic options is essential considering the stormy course of hepatitis E infection during pregnancy and teratogenicity of all available options.

The global epidemiology of hepatitis E virus infection: A systematic review and meta-analysis

BACKGROUND AND AIMS

Hepatitis E virus (HEV), as an emerging zoonotic pathogen, is a leading cause of acute viral hepatitis worldwide, with a high risk of developing chronic infection in immunocompromised patients. However, the global epidemiology of HEV infection has not been comprehensively assessed. This study aims to map the global prevalence and identify the risk factors of HEV infection by performing a systematic review and meta-analysis.

METHODS

A systematic searching of articles published in Medline, Embase, Web of science, Cochrane and Google scholar databases till July 2019 was conducted to identify studies with HEV prevalence data. Pooled prevalence among different countries and continents was estimated. HEV IgG seroprevalence of subgroups was compared and risk factors for HEV infection were evaluated using odd ratios (OR).

RESULTS

We identified 419 related studies which comprised of 1 519 872 individuals. A total of 1 099 717 participants pooled from 287 studies of general population estimated a global anti-HEV IgG seroprevalence of 12.47% (95% CI 10.42-14.67; I²  = 100%). Notably, the use of ELISA kits from different manufacturers has a substantial impact on the global estimation of anti-HEV IgG seroprevalence. The pooled estimate of anti-HEV IgM seroprevalence based on 98 studies is 1.47% (95% CI 1.14-1.85; I²  = 99%). The overall estimate of HEV viral RNA-positive rate in general population is 0.20% (95% CI 0.15-0.25; I²  = 98%). Consumption of raw meat (P = .0001), exposure to soil (P < .0001), blood transfusion (P = .0138), travelling to endemic areas (P = .0244), contacting with dogs (P = .0416), living in rural areas (P = .0349) and receiving education less than elementary school (P < .0001) were identified as risk factors for anti-HEV IgG positivity.

CONCLUSIONS

Globally, approximately 939 million corresponding to 1 in 8 individuals have ever experienced HEV infection. 15-110 million individuals have recent or ongoing HEV infection. Our study highlights the substantial burden of HEV infection and calls for increasing routine screening and preventive measures.

Hepatitis E virus infection during pregnancy

BACKGROUND

Hepatitis E virus (HEV) generally causes self-limiting viral hepatitis. However, in pregnant women, HEV infection can be severe and has been associated with up to 30% mortality in the third trimester. Additionally, HEV infection in pregnancy is also associated with high rates of preterm labor and vertical transmission.

MAIN BODY

HEV is now recognized as a global health problem in both developing and industrialized countries. HEV can be transmitted via the fecal-oral route, zoonotic route, and blood transfusion route. An altered immune status, hormonal levels, and viral factors may be related to the severity of the disease. Currently, no established treatment is available for HEV in pregnant women. A Chinese vaccine has been demonstrated to be protective against HEV in the general population and seems to be safe in pregnancy; however, its safety and efficacy in a large population of pregnant women remain to be determined.

CONCLUSION

This review summarizes the current knowledge about HEV infection during pregnancy and focuses on the epidemiology, clinical manifestations, mechanisms underlying severe liver injury, and management and prevention of HEV infection during pregnancy. Considering that HEV infection during pregnancy may result in poor outcomes, screening for and monitoring HEV infection early in pregnancy should be taken into account. In addition, a better understanding of the pathogenesis will help to develop potential treatment strategies targeting HEV infection in pregnancy.

A 5-year Single-Center Experience of Hepatitis E Virus Infection During Pregnancy

OBJECTIVE

The study was designed to examine the hypothesis whether the course and severity of hepatitis E virus (HEV)-related liver disease is worse during pregnancy.

METHOD

The prospective study included 1088 patients (550 pregnant; 538 nonpregnant) with clinically and biochemically confirmed acute viral hepatitis (AVH) or acute liver failure (ALF) and were subjected to a complete panel of hepatitis serology.

RESULTS

In the pregnant cohort, HEV was the cause of infection in 80.36% (442/550) of cases, whereas non-HEV accounted for 19.63 (108/550) of cases. In the ALF pregnant group, the prevalence of HEV was observed in 73.38% (102/139) of cases, whereas other viruses accounted for 26.61% (37/139) of illness. Ninety-eight of 129 (75.96%) cases of HEV-infected pregnant women died, whereas non-HEV infection was responsible for only 31 of 129 (24.04%) cases' death in comparison. Serum viral load in the ALF group was also significantly higher than that in the AVH group in the pregnant (24578.6 ± 12410.3 vs. 6821.9 ± 1832.7, respectively) cohort and nonpregnant cohort (583.6 ± 187.34 vs. 298.68 ± 65.77, respectively).

CONCLUSION

HEV infection has a higher incidence, more severe course, and greater mortality in the pregnant cohort than in the nonpregnant cohort.

Seroprevalence of hepatitis E virus among different age groups in Tehran, Iran

Hepatitis E virus (HEV) is considered to be a public health problem on a global scale, especially in developing countries. This study aims to investigate the seroprevalence of HEV in the Tehrani population. This descriptive-analytical study was carried out between the years 2017 and 2018 in Tehran, Iran. A total of 493 individuals whose blood samples and demographic data were collected via questionnaires through random cluster sampling were selected. To determine the presence of specific IgG antibody against HEV, commercial kits were used through ELISA. Chi-squared tests, logistic regression and t test were also required to conduct the statistical analysis. Of the 493 participants, with a mean age of 40.98 ± 17.10 years, included in this study, 180 were men and 313 were women. Of these, 48 (9.7%) had IgG antibodies against HEV. No significant difference was observed between the sexes (or different age groups) and positive antibody. It has been reported that the prevalence rate of this infection is high in Tehran, which is indicative of the endemic nature of this infection in society. The results of this study are similar to those obtained from the east of Golestan province, Iran but different from those obtained from Isfahan province, Iran. As a high percentage of people are susceptible to the infection in society, it is likely to have the prevalence of an epidemic.

Hepatitis E as a cause of adult hospitalization in Bangladesh: Results from an acute jaundice surveillance study in six tertiary hospitals, 2014-2017

In the absence of reliable data on the burden of hepatitis E virus (HEV) in high endemic countries, we established a hospital-based acute jaundice surveillance program in six tertiary hospitals in Bangladesh to estimate the burden of HEV infection among hospitalized acute jaundice patients aged ≥14 years, identify seasonal and geographic patterns in the prevalence of hepatitis E, and examine factors associated with death.

We collected blood specimens from enrolled acute jaundice patients, defined as new onset of either yellow eyes or skin during the past three months of hospital admission, and tested for immunoglobulin M (IgM) antibodies against HEV, HBV and HAV. The enrolled patients were followed up three months after hospital discharge to assess their survival status; pregnant women were followed up three months after their delivery to assess pregnancy outcomes. From December’2014 to September’2017, 1925 patients with acute jaundice were enrolled; 661 (34%) had acute hepatitis E, 48 (8%) had hepatitis A, and 293 (15%) had acute hepatitis B infection. Case fatality among hepatitis E patients was 5% (28/589). Most of the hepatitis E cases were males (74%; 486/661), but case fatality was higher among females—12% (8/68) among pregnant and 8% (7/91) among non-pregnant women. Half of the patients who died with acute hepatitis E had co-infection with HAV or HBV. Of the 62 HEV infected mothers who were alive until the delivery, 9 (15%) had miscarriage/stillbirth, and of those children who were born alive, 19% (10/53) died, all within one week of birth. This study confirms that hepatitis E is the leading cause of acute jaundice, leads to hospitalizations in all regions in Bangladesh, occurs throughout the year, and is associated with considerable morbidity and mortality. Effective control measures should be taken to reduce the risk of HEV infections including improvements in water quality, sanitation and hygiene practices and the introduction of HEV vaccine to high-risk groups.

In the absence of reliable surveillance data on the burden of hepatitis E in endemic countries, we conducted a hospital-based acute jaundice surveillance study over a two and a half year period in six tertiary hospitals in Bangladesh. The study confirms that HEV infections occur throughout the year, and is a major (34%) cause of acute jaundice in tertiary hospitals in Bangladesh. Three-quarters of the acute hepatitis E cases were male, and HEV infection was higher among patients residing in urban areas than patients in rural areas (41% vs 32%). The overall case fatality rate of acute HEV infections in hospitals was 5%, but was higher among pregnant women (12%). Hepatitis E patients who died were more likely to have co-infection with HAV or HBV than the HEV infected patients who did not die. Fifteen percent of HEV infected mothers had miscarriage/stillbirth. Of the children who were born alive, 19% died, all within one week of birth. Considering the high burden of hepatitis E among hospitalized acute jaundice patients, Bangladesh could take control measures to reduce this risk including improvements in water quality, sanitation and hygiene practices and the introduction of hepatitis E vaccine in high-risk areas.

The outcomes of transient elevation of maternal liver enzymes preceding laser treatment for twin-twin transfusion syndrome

BACKGROUND

A proportion of twin-twin transfusion syndrome (TTTS) patients may have elevated liver enzymes (ELEzs) before fetoscopic laser therapy, but the incidence of ELEzs before laser therapy and the association with the perinatal outcomes after laser therapy remain unclear.

METHODS

From October 2008 to April 2015, 93 patients with TTTS who received fetoscopic laser therapy at our hospital were included in this study, and aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were measured within 24 h before therapy. If ELEzs (AST > 34 U/L or ALT > 36 U/L) were observed before therapy, the AST and ALT levels were evaluated within 24 h after therapy. The pre-operative characteristics and post-therapy outcomes were compared between patients with and without ELEzs.

RESULTS

Among 93 TTTS patients before laser operation, 18 patients (were found with ELEzs (19.4%) before laser therapy. In 17 (94.4%) of the 18 cases, their liver enzymes values dropped after laser surgery. Maternal body mass index, age, gestational age of laser therapy, hemoglobin level before laser therapy and survival rates after laser therapy were not significantly different between TTTS with and without ELEzs. The maternal hemoglobin dropped significantly from 10.8 [1.6] g/dL before surgery to 9.6 [1.5] g/dL after laser therapy in TTTS with ELEzs (p < 0.001).

CONCLUSION

An elevated liver enzyme was not associated with poor perinatal outcomes in patients with TTTS after laser therapy. The authors suspected that the reduced liver enzymes values after laser therapy could partly arise from the hemo-dilution effect.

Rapid High-Yield Transient Expression of Swine Hepatitis E ORF2 Capsid Proteins in Nicotiana benthamiana Plants and Production of Chimeric Hepatitis E Virus-Like Particles Bearing the M2e Influenza Epitope

The Hepatitis E virus (HEV) is a causative agent of acute hepatitis, mainly transmitted by the fecal-oral route or zoonotic. Open reading frame (ORF) 2 encodes the viral capsid protein, which is essential for virion assembly, host interaction, and inducing neutralizing antibodies. In this study, we investigated whether full-length and N- and C-terminally modified versions of the capsid protein transiently expressed in N. benthamiana plants could assemble into highly-immunogenic, virus-like particles (VLPs). We also assessed whether such VLPs can act as a carrier of foreign immunogenic epitopes, such as the highly-conserved M2e peptide from the Influenza virus. Plant codon-optimized HEV ORF2 capsid genes were constructed in which the nucleotides coding the N-terminal, the C-terminal, or both parts of the protein were deleted. The M2e peptide was inserted into the P2 loop after the residue Gly556 of HEV ORF2 protein by gene fusion, and three different chimeric constructs were designed. Plants expressed all versions of the HEV capsid protein up to 10% of total soluble protein (TSP), including the chimeras, but only the capsid protein consisting of aa residues 110 to 610 (HEV 110–610) and chimeric M2 HEV 110–610 spontaneously assembled in higher order structures. The chimeric VLPs assembled into particles with 22–36 nm in diameter and specifically reacted with the anti-M2e antibody.

Updates in Hepatitis E virus (HEV) field; lessons learned from human liver chimeric mice

Hepatitis E virus (HEV) is the most common cause of viral hepatitis globally, and it is an emerging pathogen in developed countries. In vivo studies of HEV have long been hindered due to the lack of an efficient small animal model. Recently, human liver chimeric mice were described as an elegant model to study chronic HEV infection. HEV infection was established in mice with humanized liver that were challenged with stool preparations containing HEV genotype (gt)1 and/or gt3. An increase in viral load and the level of HEV Ag in mouse samples were markers of active infection. Plasma-derived HEV preparations were less infectious. The kinetics of HEV ORF2 Ag during HEV infection and its impact on HEV diagnosis were described in this model. In addition, the nature of HEV particles and HEV ORF2 Ag were characterized. Moreover, humanized mice were used to study the impact of HEV infection on the hepatic innate transcriptome and evaluation of anti-HEV therapies. This review highlights recent advances in the HEV field gathered from well-established experimental mouse models, with an emphasis on this model as a tool for elucidating the course of HEV infection, the study of the HEV life cycle, the interaction of the virus with the host, and the evaluation of new anti-HEV therapies.

Characterization of Hepatitis Delta Virus Among Pregnant Women of Pakistan

Hepatitis delta virus (HDV) is a highly pathogenic virus and causes rapid disease progression from fulminant hepatitis to development of hepatocellular carcinoma in patients infected with hepatitis B virus (HBV). HDV is endemic in Pakistan; however, there are no available data on HDV prevalence among the high-risk group of HBV-infected pregnant women. A total of 1,394 pregnant women, visiting different public-sector hospitals in Lahore, were enrolled in this study. Their demographic data and blood samples were collected from May 2016 to July 2017. Samples were screened for both HBsAg and anti-HDV. Anti-HDV positive samples were tested for HDV RNA, and samples positive for HDV RNA were further sequenced to determine the HDV genotype. Of the 1,394 samples, HBsAg was positive in 63 (4.5%). Of these 63 HBsAg-positive samples, 13 (20.63%) were positive for anti-HDV. Of the 13 HBsAg/anti-HDV positive samples, HDV RNA was detected in 4 (30.8%) samples and all 4 carried HDV genotype 1. The age of enrolled women varied from 20 to 40 years, with most of the women living in urban areas, having education more than secondary school level, belonging to middle class, and being housewives. Majority of the tested women were of age from 25 to 30 years (39.2%); however, the prevalence of HBV was higher in age group 31-35 years (10.7%, confidence interval [CI]: 4.73-16.67); however, anti-HDV prevalence was 1.9% (CI: -0.7 to 4.7). This study is the first report on HDV prevalence among pregnant women in Pakistan. Our study showed a high predominance of HDV (20.63%) in HBV-infected pregnant women and the prevalence of HDV genotype 1 infection. The findings contribute to a better understanding of the HDV/HBV coinfection among pregnant women and circulating HDV genotypes in the country.

Targeted hepatitis E vaccination for women of childbearing age is cost-effective in China

BACKGROUND

Hepatitis E virus (HEV) infection is hyper-endemic in China, it is characterized with a high morbidity of fulminant hepatitis and mortality in pregnant women. The first hepatitis E vaccine, HEV 239, was licensed in China in 2011 which provides an effective preventive measure.

OBJECTIVE

To evaluate the cost-effectiveness of vaccination with HEV 239 in women of childbearing age in China and whether HEV antibody screening should be considered before vaccination.

METHODS

A decision tree-Markov model was constructed to simulate HEV infection in a closed female cohort with an average first-marriage age of 25 years and evaluate health and economic outcomes of two potential vaccination strategies, direct vaccination and combined screening and vaccination, from a societal perspective. An incremental cost-effectiveness ratio (ICER, additional costs per disability-adjusted life-year (DALY) averted) was calculated for each vaccination strategy versus no vaccination and between two vaccination strategies. Univariate and probabilistic sensitivity analyses were conducted to assess the robustness of the model findings.

RESULTS

ICERs of direct vaccination and combined screening and vaccination versus no vaccination were $4040 and $3114 per DALY averted, respectively, much lower than 1-time Chinese per-capita GDP ($8127). Direct vaccination would need additional $45,455 for each DALY averted compared with combined screening and vaccination, far more than the 3-time per-capita GDP. Probabilistic sensitivity analyses confirmed our findings that two vaccination strategies would be cost-effective if the willingness-to-pay reached the 1-time per-capita GDP, and that combined screening and vaccination would be more cost-effective than direct vaccination strategy.

CONCLUSION

Vaccinating women of childbearing age with HEV 239 would cost less than the 1-time per-capita GDP for each DALY averted in China, and the vaccination with a prior screening would be the optimal option.

Hepatitis E Virus Replication

Hepatitis E virus (HEV) is a small quasi-enveloped, (+)-sense, single-stranded RNA virus belonging to the Hepeviridae family. There are at least 20 million HEV infections annually and 60,000 HEV-related deaths worldwide. HEV can cause up to 30% mortality in pregnant women and progress to liver cirrhosis in immunocompromised individuals and is, therefore, a greatly underestimated public health concern. Although a prophylactic vaccine for HEV has been developed, it is only licensed in China, and there is currently no effective, non-teratogenic treatment. HEV encodes three open reading frames (ORFs). ORF1 is the largest viral gene product, encoding the replicative machinery of the virus including a methyltransferase, RNA helicase, and an RNA-dependent RNA polymerase. ORF1 additionally contains a number of poorly understood domains including a hypervariable region, a putative protease, and the so-called ‘X’ and ‘Y’ domains. ORF2 is the viral capsid essential for formation of infectious particles and ORF3 is a small protein essential for viral release. In this review, we focus on the domains encoded by ORF1, which collectively mediate the virus’ asymmetric genome replication strategy. We summarize what is known, unknown, and hotly debated regarding the coding and non-coding regions of HEV ORF1, and present a model of how HEV replicates its genome.

Epidemiology of Genotype 1 and 2 Hepatitis E Virus Infections

Hepatitis E virus (HEV) genotypes 1 and 2 are responsible for the majority of acute viral hepatitis infections in endemic areas in South Asia and sub-Saharan Africa. In addition to frequent sporadic illnesses throughout the year, these viruses often cause large epidemics in association with monsoon rains in Asia or during humanitarian crises in Africa. Clinical hepatitis commonly involves adults more often than young children, with an overall mortality of ∼1%. However, the mortality among pregnant women is often 30% or higher. HEV infection in pregnant women frequently leads to infant mortality or premature delivery. Hepatitis E is an important, yet largely neglected, global public health problem.

Infectious hepatitis: A 3-year retrospective study at a tertiary care hospital in India

Context

Acute viral hepatitis (AVH) is predominantly caused by hepatitis A virus (HAV) and hepatitis E virus (HEV), the prevalence of which varies in different geographical regions.

Aims

This study aimed to determine the prevalence of HAV and HEV infections in patients with AVH, the rate of HAV-HEV co-infection and the prevalence of HEV infection among pregnant women with hepatitis.

Settings and Design

It was a retrospective observational study conducted over 3 years from January 2015 to December 2017, after obtaining clearance from the institutional ethics committee.

Subjects and Methods

A total of 675 serum samples were collected from patients with a clinical diagnosis of AVH, between January 2015 and December 2017. The study population included outdoor and hospitalised patients between 3 and 70 years of age who presented with signs and symptoms of hepatitis. The presence of IgM anti-HAV and IgM anti-HEV antibodies in serum were assessed by enzyme-linked immunosorbent assay.

Statistical Analysis Used

Chi-square test.

Results

The prevalence of HAV, HEV and HAV-HEV co-infection was found to be 6.96%, 9.63% and 2.07%, respectively. Among males, this was 7.3%, 8.8% and 2.6%, respectively and in females 6.7%, 10.2% and 1.7%, respectively. However, these differences in the prevalence rates were of no statistical significance. The prevalence of HEV infection in pregnant women with hepatitis was 9.4%. HAV and HEV infections showed a seasonal trend with predominance during summer and rainy seasons (May to September).

Conclusions

A higher seroprevalence of HEV as compared to HAV together with a co-infection rate of 2.07% mandates screening for HEV in all suspected cases of acute hepatitis, particularly pregnant women in whom the outcomes of HEV infection are poor. Health and civic authorities should make necessary efforts to counter epidemic or outbreak situations, thus reducing morbidity, mortality and economic burden.

Emerging zoonotic viral infections of occupational health importance

Emerging viral infections represent a public health risk pointed out by the spreading of pathogens with potential zoonotic risk. Moreover, the risk of zoonosis has probably been underestimated in occupational settings. A literature review between 2007 and 2018 was performed to identify evidences concerning the epidemiological associations between some emerging viruses and occupational diseases. Observational studies and case-reports were selected and analyzed. West Nile Virus (WNV) disease, Crimean-Congo Hemorrhagic Fever (CCHF) disease and Hepatitis E virus (HEV) infection were included in the review for their potential zoonotic transmission. The most important risk factor for acquiring WNV infection and CCHF infection is the exposure to infected mosquitoes and ticks, respectively; therefore, outdoor workers are at risk of infection. HEV is responsible for epidemics and endemics of acute hepatitis in humans, that can become infected through waterborne, foodborne and zoonotic transmission routes. A total of 10, 34 and 45 eligible studies for WNV, CCHF virus (CCFHV) and HEV, respectively, were analyzed by year, country, study design, risk group and outcomes. The occupational risk groups mainly included farm and agricultural workers, veterinarians, slaughterers, animal handlers, healthcare workers and soldiers. These findings support the need to develop effective interventions to prevent transmission of emerging viruses.