Emerging hepatitis E virus compared with hepatitis A virus: A new sanitary challenge

Area of Science:

• Hepatology
• Virology
• Infectious Diseases

Background:

• Hepatitis A virus (HAV) and Hepatitis E virus (HEV) are significant causes of human liver disease.
• Both viruses are primarily transmitted via the fecal-oral route, leading to historical comparisons in incidence and pathogenicity, particularly in areas with poor sanitation.
• Recent research highlights diverging trends: HAV incidence is decreasing in developed nations, while HEV is recognized as an emerging, underdiagnosed pathogen.

Purpose of the Study:

• To review and contrast the epidemiological and clinical characteristics of Hepatitis A and E.
• To explore the emerging understanding of HEV as a zoonotic and underdiagnosed infection.
• To investigate the role of viral genome variability and plasticity in the distinct clinical evolution and pathogenesis of HAV and HEV.

Main Methods:

• Comparative analysis of epidemiological data for HAV and HEV.
• Review of recent molecular and clinical studies on HEV, including zoonotic and extrahepatic manifestations.
• Examination of viral genome variability and its correlation with clinical outcomes.

Main Results:

• HAV infections are declining in developed countries due to improved public health measures.
• HEV infections are increasingly recognized, often linked to zoonotic transmission, and present with extrahepatic signs (neurological, renal) and chronic potential in immunocompromised individuals.
• Significant differences in pathogenesis and clinical presentation are emerging between HAV and HEV.

Conclusions:

• HAV and HEV, despite shared transmission routes, exhibit increasingly distinct epidemiological and clinical profiles.
• HEV represents an emerging pathogen with broader clinical implications, including zoonotic potential and extrahepatic disease.
• Understanding viral genetic variability is crucial for elucidating the clinical impact and pathogenesis of these hepatitis viruses.