Hepatitis E infection: A review

Evaluating the Efficacy and Safety of Hepatitis E Vaccination in Reproductive-Age Women: A Systematic Review and Meta-Analysis

BACKGROUND

Hepatitis E virus (HEV) infection presents a significant health risk in endemic regions, especially for pregnant women, who face higher risks of severe complications, including maternal and fetal mortality. The recombinant HEV vaccine, HEV239, has demonstrated high efficacy in the general population, yet data on its safety and efficacy in women of a childbearing age remain limited. This systematic review and meta-analysis aim to evaluate the safety and effectiveness of HEV239 in this specific population, with a focus on pregnancy-related outcomes.

METHODS

A comprehensive search was conducted in PubMed, Embase, Cochrane Library, and Scopus, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were included if they reported outcomes on HEV239's safety or efficacy in women of childbearing age, with data being extracted and analyzed for immunogenicity, HEV incidence, and maternal adverse events. The risk of bias was assessed using the Cochrane and Newcastle Ottawa Scales, and a random-effects meta-analysis was performed.

RESULTS

Three studies, enrolling over 23,000 participants, were included in the current systematic review, with two meeting the criteria for meta-analysis. HEV239 demonstrated high efficacy in preventing hepatitis E infection, with no significant increase in adverse pregnancy outcomes such as stillbirth or elective termination. However, there was an elevated risk of miscarriage (odds ratio [OR], 1.60; 95% confidence interval [CI], 0.99-2.57). The analysis revealed high heterogeneity for miscarriage outcomes (I2 = 67%), reflecting variability in study designs and populations.

CONCLUSIONS

HEV239 is effective in preventing HEV infection among women of childbearing age, although caution is advised when administering the vaccine near conception due to potential miscarriage risks. Future studies should focus on understanding the biological mechanisms and timing-specific safety to guide vaccination recommendations.

Diagnostic accuracy of hepatitis E virus antibody tests: A comprehensive meta-analysis

AIM

Hepatitis E virus (HEV) is a major global health issue, with an estimated 20 million infections annually. Although polymerase chain reaction (PCR) is the diagnostic gold standard due to its precision, it is expensive and technically demanding. Antibody tests offer a more practical and cost-effective alternative, although their accuracy can vary due to factors, such as test manufacturer, antigen composition, HEV genotype, and host immune status.

METHODS

A comprehensive search was conducted in PubMed, Cochrane, Scopus, and Web of Science databases. Studies included comparing the sensitivity and specificity of immunoglobulin M or immunoglobulin G antibody tests to PCR. Exclusion criteria were non-PCR comparisons, sample sizes under 10, IgA or antigen tests, non-human samples, or missing sensitivity and specificity data. Only English-language full-texts or abstracts were considered. Data analysis was performed using Meta-DTA v2.1.1 and Stata 16.0.

RESULTS

The meta-analysis evaluated 8054 blood samples from 21 studies. Immunoglobulin M antibody tests demonstrated an overall sensitivity of 83% (95% CI 76-88) and specificity of 98% (95% CI 97-99). Immunoglobulin G tests showed a sensitivity of 74% (95% CI 62-82) and specificity of 89% (95% CI 84-93). Among manufacturers, Wantai was the most accurate for immunoglobulin M detection, whereas MP led for immunoglobulin G. Notably, test sensitivity improved when the test protein genotype aligned with the HEV genotype.

CONCLUSION

This meta-analysis confirmed that antibody assays have a good sensitivity and high specificity to detect HEV infection in situations where PCR is not feasible, highlighting their potential as a practical diagnostic tool.

Viral Hepatitis: Host Immune Interaction, Pathogenesis and New Therapeutic Strategies

Viral hepatitis is a major cause of liver illness worldwide. Despite advances in the understanding of these infections, the pathogenesis of hepatitis remains a complex process driven by intricate interactions between hepatitis viruses and host cells at the molecular level. This paper will examine in detail the dynamics of these host-pathogen interactions, highlighting the key mechanisms that regulate virus entry into the hepatocyte, their replication, evasion of immune responses, and induction of hepatocellular damage. The unique strategies employed by different hepatitis viruses, such as hepatitis B, C, D, and E viruses, to exploit metabolic and cell signaling pathways to their advantage will be discussed. At the same time, the innate and adaptive immune responses put in place by the host to counter viral infection will be analyzed. Special attention will be paid to genetic, epigenetic, and environmental factors that modulate individual susceptibility to different forms of viral hepatitis. In addition, this work will highlight the latest findings on the mechanisms of viral persistence leading to the chronic hepatitis state and the potential implications for the development of new therapeutic strategies. Fully understanding the complex host-pathogen interactions in viral hepatitis is crucial to identifying new therapeutic targets, developing more effective approaches for treatment, and shedding light on the mechanisms underlying progression to more advanced stages of liver damage.

Role of pseudotyped viruses in understanding epidemiology, pathogenesis and immunity of viral diseases affecting both horses and humans

In this review, we explore how pseudotyped viruses (PVs) are being applied to the study of viruses affecting both humans and horses. For the purposes of this review, we define PVs as non-replicative viruses with the core of one virus and the surface protein(s) of another and encapsulating a reporter gene such as luciferase. These 'reporter' PVs enable receptor-mediated entry into host cells to be quantified, and thus can be applied to study the initial stages of viral replication. They can also be used to test antiviral activity of compounds and measure envelope protein-specific antibodies in neutralisation tests.

Seroprevalence of the Hepatitis E Virus in Indigenous and Non-Indigenous Communities from the Brazilian Amazon Basin

Hepatitis E virus (HEV) infection is a common cause of acute viral hepatitis in tropical regions. In Brazil, HEV G3 is the only genotype detected to date. Reports on HEV prevalence are heterogeneous. We aimed to compare the prevalence of anti-HEV among three populations living in the Brazilian Amazon basin. Two cross-sectional studies were conducted in urban, rural, and Yanomami indigenous areas. Plasma samples from 428 indigenous and 383 non-indigenous subjects were tested for anti-HEV IgG using enzyme-linked immunosorbent assays. The overall prevalence of anti-HEV was 6.8% (95%CI: 5.25-8.72), with 2.8% (12/428) found in the Yanomami areas, 3% (3/101) in an urban area, and 14.2% (40/282) in a rural area. Multivariate logistic analysis indicated that patients aged 31-45 years or ≥46 years are more likely to present anti-HEV positivity, with a respective aOR of 2.76 (95%CI: 1.09-7.5) and 4.27 (95%CI: 1.58-12.35). Furthermore, residence in a rural area (aOR: 7.67; 95%CI: 2.50-33.67) represents a relevant risk factor for HEV infection. Additional studies detecting HEV RNA in fecal samples from both humans and potential animal reservoirs are necessary to comprehensively identify risk factors associated with HEV exposure.