Molecular identification and genotyping of hepatitis E virus from Southern Punjab, Pakistan

Burden of acute hepatitis E virus in South Asia: Insights from Global Burden of Disease study 2021

BACKGROUND

Despite global progress, South Asian countries account for a disproportionate burden of Acute hepatitis E (AHE). Understanding the burden of AHE in this region is crucial for targeted interventions.

METHODS

We used Global Burden of Disease (GBD) 2021 data to assess the burden of AHE across eight South Asian countries from 1990 to 2021. Joinpoint regression was used to analyze temporal trends and Estimated Annual Percentage Change (EAPC) was calculated to quantify trends. The relationship between age-standardized disability-adjusted life years rate (ASDR) and socio-demographic index (SDI) was assessed using smoothing spline model and Spearman rank correlation. Rates are expressed per 100,000 population.

RESULTS

Bangladesh had highest age-standardized prevalence rate (ASPR) [33.27 (95 % Uncertainty Interval: 27.64 to 39.95)] and age-standardized incidence rate (ASIR) [433.01 (359.61 to 519.76)], while India had highest ASDR [9.52 (4.33 to 18.42)]. Males had higher ASIR and ASPR than females in most South Asian countries, except Bhutan and India, and higher ASDR except in Nepal and Pakistan. Bhutan had the highest EAPC for both sexes in ASPR and ASIR, while India had the highest EAPC in ASDR, closely followed by Bhutan for both sexes. Age group 5-9 had the highest ASPR and ASIR whereas <1-year age group had the highest ASDR. There was an inverse relationship between ASDR and SDI (R = -0.49, p < 0.01).

CONCLUSION

South Asia bears a high burden of AHE, with variations across countries. Improvements in Water Sanitation and Hygiene (WASH) services are needed to achieve Sustainable Development Goals 3 and 6.

From discovery to treatment: tracing the path of hepatitis E virus

The hepatitis E virus (HEV) is a major cause of acute viral hepatitis worldwide. HEV is classified into eight genotypes, labeled HEV-1 through HEV-8. Genotypes 1 and 2 exclusively infect humans, while genotypes 3, 4, and 7 can infect both humans and animals. In contrast, genotypes 5, 6, and 8 are restricted to infecting animals. While most individuals with a strong immune system experience a self-limiting infection, those who are immunosuppressed may develop chronic hepatitis. Pregnant women are particularly vulnerable to severe illness and mortality due to HEV infection. In addition to liver-related complications, HEV can also cause extrahepatic manifestations, including neurological disorders. The immune response is vital in determining the outcome of HEV infection. Deficiencies in T cells, NK cells, and antibody responses are linked to poor prognosis. Interestingly, HEV itself contains microRNAs that regulate its replication and modify the host's antiviral response. Diagnosis of HEV infection involves the detection of HEV RNA and anti-HEV IgM/IgG antibodies. Supportive care is the mainstay of treatment for acute infection, while chronic HEV infection may be cleared with the use of ribavirin and pegylated interferon. Prevention remains the best approach against HEV, focusing on sanitation infrastructure improvements and vaccination, with one vaccine already licensed in China. This comprehensive review provides insights into the spread, genotypes, prevalence, and clinical effects of HEV. Furthermore, it emphasizes the need for further research and attention to HEV, particularly in cases of acute hepatitis, especially among solid-organ transplant recipients.

Hepatitis E Virus: What More Do We Need to Know?

Hepatitis E virus (HEV) infection is typically a self-limiting, acute illness that spreads through the gastrointestinal tract but replicates in the liver. However, chronic infections are possible in immunocompromised individuals. The HEV virion has two shapes: exosome-like membrane-associated quasi-enveloped virions (eHEV) found in circulating blood or in the supernatant of infected cell cultures and non-enveloped virions ("naked") found in infected hosts' feces and bile to mediate inter-host transmission. Although HEV is mainly spread via enteric routes, it is unclear how it penetrates the gut wall to reach the portal bloodstream. Both virion types are infectious, but they infect cells in different ways. To develop personalized treatment/prevention strategies and reduce HEV impact on public health, it is necessary to decipher the entry mechanism for both virion types using robust cell culture and animal models. The contemporary knowledge of the cell entry mechanism for these two HEV virions as possible therapeutic target candidates is summarized in this narrative review.

Genotypic analysis of hepatitis E virus (HEV) from sporadic symptomatic cases in Pakistan

Pakistan is the fifth most populous nation in the world and faces several challenges, including devastating floods, sub-optimal sanitary conditions, clustered accommodations, and unregulated cross-border movements. These drastic population shifts make it vulnerable to the efficient spread of the Hepatitis E virus (HEV). The current study analyzed the genotypic characteristics and variants of the Hepatitis E virus circulating in the population of Pakistan. A total of 75 ELISA-IgM positive samples were collected from three metropolitan cities: Lahore, Peshawar, and Karachi, and subjected to viral RNA extraction. The amplification of the HEV RNA-dependent RNA polymerase (RdRp) region was done using Nested PCR and degenerate primers. Out of the total, 40% of the samples were positive for HEV RNA. Sequencing and phylogenetic analysis identified the new HEV isolates as Subtype 1 g, a subtype within an existing HEV genotype 1. This shift warrants investigation into its impact on clinical manifestation and disease severity. Importantly, this study marks the first HEV subtype analysis in Pakistan, contributing valuable insights into subtype diversity and prevalence in the region.