Molecular epidemiology of hepatitis A virus infection in Northeast India

Recent advances in hepatitis A virus research and clinical practice guidelines for hepatitis A virus infection in Japan

In 2018, there was a hepatitis A outbreak in Japan, and hepatitis A virus (HAV) infection is considered a sexually transmitted disease. In general, patients with hepatitis A should be given attention, and this disease should be prevented more than ever. The Japan Agency for Medical Research and Development (AMED) Hepatitis A and E viruses (HAV and HEV) Study Group has worked on the project to create "Recent Advances in Hepatitis A Virus (HAV) Research and Clinical Practice Guidelines for HAV Infection in Japan". The group consists of expert hepatologists and virologists who gathered at virtual meeting on August 5, 2023. Data about the pathogenesis, infection routes, diagnosis, complications, several factors for the severities, vaccination, and current and future treatments for hepatitis A were discussed and debated for a draft version. The participants assessed the quality of cited studies. The finalized recommendations are presented in this review. The recent advances in HAV research and clinical practice for HAV infection in Japan, have been reviewed by the AMED HAV and HEV Study Group.

A Comparison of Clinical Manifestations and Outcomes between Acute Sporadic Hepatitis A and Hepatitis E Infections in Thailand

Hepatitis A virus (HAV) and hepatitis E virus (HEV) infections often present as acute hepatitis with prodromal symptoms. These infections, transmitted via the oral-enteral route, constitute significant public health challenges, particularly in developing countries with subpar sanitary systems. The aim of the study was to describe the clinical manifestations, laboratory findings, and outcomes of hepatitis A and hepatitis E infections in Thailand. We conducted a retrospective chart review and analysis of 152 patients diagnosed with acute hepatitis A or hepatitis E from January 2007 to August 2018 at Siriraj Hospital. The hepatitis E cohort was older with a greater prevalence of comorbidities (hypertension, diabetes mellitus, chronic kidney disease, chronic hepatitis B, and post-kidney transplantation status) than the hepatitis A cohort. While the majority of hepatitis A patients presented with fever (98%) and jaundice (96%), these symptoms were less pronounced in hepatitis E patients. Furthermore, hepatitis A patients exhibited significantly higher aminotransferase and total bilirubin levels. However, clinical outcomes, such as hospitalization rates, progression to acute liver failure, and mortality, were comparable across both groups. In conclusion, although the clinical manifestations of hepatitis A and hepatitis E were similar, fever and jaundice were more prevalent and aminotransferase and bilirubin levels were higher in the HAV-infected group.

Circulation of a single hepatitis A virus genotype IIIA with two distinct clusters in different states of India

With the changing hepatitis A epidemiology in India, focal viral outbreaks are being reported from different parts of the country. This study presents Hepatitis A Virus (HAV) strain characterization (period 2009-2020) from 18 states of India. For that, blood and stool samples (n ​= ​280) were screened for HAV RNA and sequences for 5'non-coding and VP3 regions were generated from positive samples (n ​= ​68). Presence of a single IIIA genotype in all samples indicated IIIA being the only HAV genotype currently circulating in India. Interestingly, it was evident that these strains form two distinct groups suggesting independent evolution of these two clusters.

Currently circulating genotypes of Hepatitis A virus in South West, East and North East India, 2017-2018

Background

This study was carried out to understand the circulating genotypes of Hepatitis A virus (HAV) in South West, East and North East India during the period 2017-2018 as a part of acute febrile illness surveillance at the Manipal Institute of Virology.

Methods

Archived serum samples of 48 Hepatitis A confirmed cases were subjected to RNA extraction using QIAamp® Viral RNA Mini Kit (QIAGEN, Germany). The samples with molecular confirmation for HAV by reverse transcriptase real-Time PCR (Real Star® HAV RT-PCR Kit 2.0, Altona Diagnostics, GmbH, Hamburg, Germany) were further subjected to nested conventional PCR targeting the 5' UTR region. The purified PCR products were sequenced using Big Dye Terminator Kit (Applied Biosystems, USA), in a 3500 XL genetic analyzer (Applied Biosystems, USA). The edited sequences by means of MEGA X (MEGA version 10.1) were compared with reference sequences in the NCBI nucleotide database.

Results

From states of Assam, Goa, Gujarat, Karnataka, Kerala, Maharashtra, Odisha, Tamil Nadu and Tripura, 139 Hepatitis A and 33 Hepatitis E cases were reported during the study period. The median age of the acute Hepatitis A cases was 19 years (IQR 12.8-24) and most of the affected individuals were students between 10 and 19 years (52.5%). In the present study, 14 samples from Assam, Goa, Gujarat, Karnataka, Odisha, Kerala, Maharashtra and Tamil Nadu were genotyped as genotype IIIA by nested conventional polymerase chain reaction.

Conclusion

The circulating HAV genotype in South West, North East and East India between 2017 and 2018 was IIIA.

Increasing Burden of Hepatitis A in Adolescents and Adults and the Need for Long-Term Protection: A Review from the Indian Subcontinent

Hepatitis A, an acute inflammatory liver disease caused by hepatitis A virus (HAV) infection from close contact with infected people, is highly endemic in the Indian subcontinent. Due to poor sanitary conditions, most of the population is exposed to the virus in childhood. At this age, the disease is asymptomatic and provides life-long protection against the disease. Due to rapid socioeconomic development in some areas, however, pockets of the population are reaching adolescence/adulthood without prior exposure to the virus and are thus susceptible to infection. At these ages, infection carries a higher risk of symptomatic disease and complications including mortality. This review of epidemiology and burden of disease studies in the Indian subcontinent, published since 2005, shows increasing evidence of a shift from high to intermediate endemicity in high-income-typically urban-populations. The prevalence of anti-HAV antibodies (previously reported at > 90%) is lower now in adolescents and young adults (e.g., around 80% in Bangladesh and 55% in 5-15 years in India). As a result, HAV is responsible for more acute viral hepatitis predominantly in this age group (e.g., > 15 years: 3.4% in 1999 to 12.3% in 2003 or high socioeconomic status 13-20 years: 27% in 1999 to 62% in 2003), with a greater clinical and economic burden. Numerous outbreaks due to HAV have been reported [e.g., Sri Lanka (2009-2010): > 13,000 affected; Kashmir (2015-2017): 12 outbreaks; Kerala (2012-2016): 84 outbreaks] from water or food contamination. Due to current shifts in endemicity, a growing proportion of the population is no longer exposed in childhood. As the disease remains highly endemic, it also provides a source for more severe disease in susceptible people at an older age and for outbreaks. Well-tolerated and effective vaccines are available and help prevent disease burden and provide long-term protection. These should now be used more widely to protect more patients from the growing disease burden of hepatitis A. FUNDING: GlaxoSmithKline Biologicals SA. Plain language summary available for this article-please see Fig. 1 and the following link: https://doi.org/10.6084/m9.figshare.9963044.Fig. 1Plain Language Summary. Highlights the context of the article, the endemicity shift and the burden of hepatitis A in adolescents and adults and steps to be taken to address the impact of this disease.

[Markers of hepatitis A in the monkeys of the Adlers primate center.]

Hepatitis A is a widespread viral infection. The HAV strains of "human" and "monkey" origin are similar in their morphological and antigenic properties, but differ genotypically.

OBJECTIVES

The aim of this research was a comparative study of serological and molecular-genetic markers of HAV infection in monkeys born at the Adler Primate Center and in those imported from different countries.

MATERIAL AND METHODS

Fecal samples (n = 313) and serum (n = 266) from various species of monkey using ELISA and RT-PCR were studied.

RESULTS AND DISCUSSION

The frequency of anti-HAV-IgG was high (78.9%) in imported animals (vervet monkeys from Tanzania and cynomolgus monkeys from Vietnam) and as well as in various species of monkeys (rhesus monkeys, cynomolgus monkeys, green monkeys and papio hamadryas) of the Center (88.6%). At the same time, in the imported monkeys, the markers of "fresh" HAV infection (IgM-27.2%, Ag-HAV-16.7%, RNA-22.0%) were detected significantly more often (p> 0.05) than in monkeys kept at the Colony (IgM-7.5%, HAV-Ag - 5.2%, RNA - 3.6%). In general, anti-IgG reactivity ranged from 1.064 to 2.073 OD₄₅₀, anti-IgM ranged from 0.546 to 1.059 OD₄₅₀. The number of HAV-Ag was 0.496 - 1.995 OD₄₅₀. RNA HAV only in rhesus monkeys and cynomolgys monkeys born at the Colony, as well as in imported vervet monkeys was detected.

CONCLUSIONS

The data obtained indicate a wide circulation of HAV among monkeys born in the Adler Primate Center and among the imported animals. Markers of "fresh" HAV infection varied depending on the species of monkeys and their origin.

Molecular characterization of hepatitis A virus from children hospitalized at a tertiary care centre in northwest India

Background & objectives:

Hepatitis A virus (HAV) infection is a major cause of childhood hepatitis, prevalent worldwide. HAV is classified into seven genotypes I-VII; genotypes III and I are the most common among humans. The present work was carried out to identify the genotypes prevalent in children suspected to have acute viral hepatitis (AVH), hospitalized at a tertiary care centre in northwest India.

Methods:

A total of 1269 blood samples from children (0-15 yr of age) clinically suspected of viral hepatitis were screened for anti-HAV IgM. Acute phase serum was processed for RNA extraction and amplified by nested polymerase chain reaction (PCR) followed by sequencing of representative samples.

Results:

Among the 1269 samples tested, 642 (50.59%) were positive for anti-HAV IgM; among the positive samples, 171 patients having a history of less than seven days were tested by PCR, of whom 141 (82.45%) were found to be PCR positive. Nucleotide sequencing of a representative 44 samples showed high homology; all the samples were found to be of genotype IIIA.

Interpretation & conclusions:

Hepatitis A was prevalent during July to September and in predominantly children less than five years age. Only genotype IIIA was detected in all the samples.

Molecular genetic identification of isolates of the hepatitis A virus (HAV) from monkeys at Adler Primate Center

BACKGROUND

The aim of this study was to assess prevalence and genetic variability of hepatitis A virus (HAV) isolates in monkeys born and kept at Adler Primate Center, as well as in imported animals.

METHODS

The fecal samples from various species of monkeys (n = 119) were studied using reverse transcription seminested PCR, sequencing, and phylogenetic analysis.

RESULTS

HAV RNA was detected in 2 Macaca mulatta and 1 Macaca fascicularis (3.8%) kept at Adler Primate Center (n = 79) and in 11 (27.5%) Chlorocebus pygerythrus (n = 40) imported from Tanzania. Phylogenetic analysis demonstrated that all HAV strains belonged to simian genotype V, but differed from the prototype genotype V strain (AGM-27) by 5.4%-5.5%. Sequences isolated in this study differed by only 0.1%, suggesting a common source of infection.

CONCLUSIONS

This study demonstrated the asymptomatic circulation of HAV genotype V among the monkeys at Adler Primate Center, and it indicated the significant genetic diversity within this HAV genotype.

Projections of hepatitis A virus infection associated with flood events by 2020 and 2030 in Anhui Province, China

Assessing and responding to health risk of climate change is important because of its impact on the natural and societal ecosystems. More frequent and severe flood events will occur in China due to climate change. Given that population is projected to increase, more people will be vulnerable to flood events, which may lead to an increased incidence of HAV infection in the future. This population-based study is going to project the future health burden of HAV infection associated with flood events in Huai River Basin of China. The study area covered four cities of Anhui province in China, where flood events were frequent. Time-series adjusted Poisson regression model was developed to quantify the risks of flood events on HAV infection based on the number of daily cases during summer seasons from 2005 to 2010, controlling for other meteorological variables. Projections of HAV infection in 2020 and 2030 were estimated based on the scenarios of flood events and demographic data. Poisson regression model suggested that compared with the periods without flood events, the risks of severe flood events for HAV infection were significant (OR = 1.28, 95 % CI 1.05-1.55), while risks were not significant from moderate flood events (OR = 1.16, 95 % CI 0.72-1.87) and mild flood events (OR = 1.14, 95 % CI 0.87-1.48). Using the 2010 baseline data and the flood event scenarios (one severe flood event), increased incidence of HAV infection were estimated to be between 0.126/10⁵ and 0.127/10⁵ for 2020. Similarly, the increased HAV infection incidence for 2030 was projected to be between 0.382/10⁵ and 0.399/10⁵. Our study has, for the first time, quantified the increased incidence of HAV infection that will result from flood events in Anhui, China, in 2020 and 2030. The results have implications for public health preparation for developing public health responses to reduce HAV infection during future flood events.

Hepatitis A: epidemiology in resource-poor countries

PURPOSE OF REVIEW

Transmission of hepatitis A virus (HAV) infection is primarily fecal-oral. Symptomatic hepatitis, severe disease, and death are more likely to occur when infection occurs at an older age. Improvements in socioeconomic and hygienic conditions have led to a change in its epidemiology worldwide.

RECENT FINDINGS

In the last two decades, improved hygiene in several resource-poor countries has led to reduced transmission of HAV, an increase in average age at infection, and, consequently, a paradoxical increase in morbidity and mortality because of hepatitis A. In Argentina, introduction of one dose (instead of the conventional two doses, to reduce costs) of inactivated HAV vaccine at 12-month age in a universal childhood immunization program during such 'epidemiologic transition' has markedly reduced the incidence of symptomatic hepatitis A, and of fulminant hepatitis and liver transplantation caused by HAV infection. The monetary value of medical and nonmedical benefits of this strategy outweighed the expenditure on vaccination. These excellent results were possibly contingent upon a high vaccination coverage.

SUMMARY

Resource-poor countries should closely monitor the epidemiology of HAV infection and periodically undertake cost-effectiveness analyses of HAV immunization strategies. This should allow timely identification of epidemiologic transition and introduction of preventive strategies before HAV infection becomes a public health problem.

Viral excretion and antibody titers in children infected with hepatitis A virus from an orphanage in western India

BACKGROUND

Hepatitis A is endemic in India and mainly causes sporadic infections. However, children in childcare centers, schools and orphanages are vulnerable to common-source outbreaks as they have naive hosts.

OBJECTIVES

To investigate hepatitis A outbreak in an orphanage from Pune, India.

STUDY DESIGN

Monitoring of virus excretion and anti-HAV antibody levels in hepatitis A virus (HAV) infected children.

RESULTS

The orphanage housed 93 children of the age 1 month-6.5 years. Analysis of the collected serum (n=78) and stool samples (n=63) revealed 20 children to be either positive for anti-HAV IgM antibodies or excreting HAV, 14 being symptomatic and 6 asymptomatic, while 32 were already anti-HAV IgG positive either due to past HAV exposure (n=7, mean log antibody titers: 2.96) or maternal antibodies (n=25, mean log antibody titers: 1.13). Serum samples, taken 4 weeks apart, did not show any significant difference in the IgM and IgG antibody levels either. However, virus excretion decreased significantly after 15 days in symptomatic children (mean log HAV RNA copies/ml 1.03+0.30), while asymptomatic children continued to excrete higher viral loads, at constant levels (mean log HAV RNA copies/ml 2.33+0.33), for up to 90 days.

CONCLUSIONS

Though virus excretion continued up to 90 days in all HAV infected children, asymptomatic children excreted higher viral loads for longer period and hence can contribute significantly in person-to-person virus transmission. All children should be vaccinated in such set ups.

The sirtuin inhibitor sirtinol inhibits hepatitis A virus (HAV) replication by inhibiting HAV internal ribosomal entry site activity

Epigenetics plays a role in the regulation of gene expression. Epigenetic changes control gene expression at the transcriptional level. Our previous study suggested that the La protein, which is mainly localized in the nucleus, was associated with hepatitis A virus (HAV) internal ribosomal entry site (IRES)-mediated translation and HAV replication. The aim of this study was to investigate whether epigenetic compounds have effects on HAV IRES-mediated translation and HAV replication. Sirtinol, a sirtuin inhibitor, inhibited HAV IRES-mediated translation in COS7-HAV-IRES cells. Treatment with 10 μM sirtinol resulted in a significant reduction in the intracellular RNA levels of HAV HA11-1299 genotype IIIA in Huh7 cells. Epigenetic treatment with a sirtuin inhibitor may represent a new treatment option for HAV infection. In conclusion, epigenetic control was involved in HAV IRES-dependent translation and HAV replication. Special attention should also be paid to underlying viral diseases in the clinical use of epigenetic treatments for malignancies.