Transmission of Hepatitis E Virus in Developing Countries.

Area of Science:

• Virology
• Epidemiology
• Public Health

Background:

• Hepatitis E virus (HEV) exhibits significant genetic diversity across its five genotypes, influencing transmission routes and disease patterns globally.
• HEV infections manifest differently based on region and socioeconomic factors, ranging from large-scale waterborne epidemics in resource-poor settings to zoonotic transmissions in developed countries.
• Vertical transmission poses a high risk for fetal and perinatal mortality, highlighting the severity of HEV infections.

Approach:

• This review synthesizes current knowledge on HEV epidemiology, focusing on the distinct transmission dynamics of different genotypes.
• It examines the ecological and socioeconomic factors influencing HEV's global distribution and disease presentation.
• The review also considers emerging transmission routes, including zoonotic and blood transfusion-associated infections.

Key Points:

• HEV genotypes 1 and 2 are primarily associated with epidemic and endemic waterborne diseases in resource-poor countries.
• HEV genotypes 3 and 4 are increasingly linked to autochthonous, zoonotic food-borne infections in developed and developing nations, particularly through consumption of undercooked animal products.
• Zoonotic transmission of HEV-4 from pigs to humans is a growing concern in East Asia.
• Blood transfusion-associated HEV infections are recognized, prompting consideration for donor screening.

Conclusions:

• HEV presents a complex public health challenge due to its diverse genotypes and varied transmission pathways.
• Effective control strategies require tailored approaches addressing both waterborne and zoonotic transmission routes.
• Further research into HEV screening and prevention is essential, especially concerning food safety and blood transfusions.