Hepatitis E Virus (HEV) is responsible for a significant annual incidence of around 20 million infections globally, yet this figure likely underestimates the true impact. The virus was initially identified in the late 1970s during an epidemic of non-A non-B hepatitis linked to a waterborne illness, marking a pivotal moment in infectious disease history. Since then, HEV has evolved into a major contributor to icteric hepatitis and acute liver failure (ALF) on a global scale, affecting both low-income and developed countries. The spread of the Hepatitis E virus tends to align with the socio-economic status of populations, with a heightened prevalence observed in low-income countries.
Pakistan, as the fifth most populous nation, grapples with numerous challenges, including devastating floods, suboptimal sanitary conditions, crowded accommodations, and unregulated cross-border movements. These challenges collectively render the country susceptible to the efficient propagation of HEV. A recent study led by Dr. Aneela Javed aimed to discern the nature of HEV cases in Pakistan, necessitating a pioneering study due to limited genetic information surrounding the virus. Despite the notable public health impact of HEV in Pakistan, comprehensive investigations into HEV genotyping have been lacking. This study represents the initial endeavor to subtype the virus within the current geographical context.
While no zoonotic HEV was detected in samples collected from different geographical regions, including three metropolitan cities of Pakistan, human HEV viruses exhibited a noteworthy metamorphosis in their dynamics. With Genotype 1 HEV still the leading disease-causing agent, Subtyping the existing viruses revealed that Genotype 1 HEV had undergone various modifications over time, with subtypes 1a and 1g initially prominent during outbreaks in 2011. Recent genetic investigations, however, have highlighted subtype 1g as the predominant subtype. This finding is particularly intriguing, as among the numerous subtypes that once circulated, HEV subtype 1g has uniquely achieved homeostasis in the region, standing alone as the singularly detected subtype.
This revelation assumes paramount significance, guiding future vaccine development endeavors to conscientiously center upon the prevalent genotype. Prospective research for vaccine production will be crucial, considering the emerging genetic insights into the virus. Moreover, in formulating preventive strategies, emphasis should be placed on mitigating water-borne disease transmission, shifting focus from the zoonotic perspective. However, the potential zoonotic origins should not be dismissed, warranting vigilant scrutiny as a potential wellspring of the ailment.
Read the full article (Infect Genet Evol. 2024 Feb 9:118:105567): DOI: 10.1016/j.meegid.2024.105567
