HEV evolution in chronic hepatitis E
Hepatitis E virus (HEV) can persist in immunocompromised patients, and ribavirin therapy may fail when resistance-associated variants emerge in the viral population. The evolutionary dynamics towards treatment failure remain poorly defined because comparative clinical and in vitro systems are scarce. Our study employed longitudinal deep sequencing of a chronic hepatitis E transplant recipient and two persistently infected cell cultures derived from the same patient HEV strain, demonstrating that cyclical ribavirin exposure increases synonymous and non-synonymous variant densities across the viral genome and selects both known and previously undescribed resistance-associated mutations. Variants identified in patient and culture cluster mainly in ORF1, identifying this region as the principal determinant of ribavirin treatment failure. These findings indicate that cyclical ribavirin pressure promotes HEV diversification and antiviral non-response, and support use of early, continuous, high-dose treatment when initial reduction of immunosuppression does not clear infection.