Work

Beyond hepatitis D virus: the discovery of animal deltaviruses, their diversity, helpers and their position in an expanding world of circular RNA replicons

Year: 2026

Type: review

Abstract: Hepatitis D virus (HDV) was long considered a singular human satellite virus that depends on hepatitis B virus (HBV) for envelopment and transmission. Recent metatranscriptomic mining has uncovered a growing diversity of HDV-like viruses, we term deltaviruses, across vertebrates, invertebrates, and environmental samples, overturning assumptions about strict hepatic tropism and obligatory hepadnavirus helpers. Here, we synthesize shared structural and replication principles of deltaviruses: rolling-circle amplification by host polymerases and ribozyme-driven RNA processing. We then discuss emerging models of helper-virus association, including flexible glycoprotein usage and 'Trojan Horse' co-packaging within unrelated virions, and consider implications for tissue tropism, host shifting, and zoonotic potential. Finally, we highlight key priorities for linking sequence discovery to mechanism, ecology, and disease.

Source: Current Opinion in Virology

DOI: 10.1016/j.coviro.2026.101539

Authors: Zoé Denis, Valérie Courgnaud, Karim Majzoub

Institutions: Centre National de la Recherche Scientifique, Institut de Génétique Moléculaire de Montpellier

Language: English

Topic: Hepatitis B Virus Studies

Subfield: Epidemiology

Field: Medicine

Domain: Health Sciences

Open Access status: hybrid

Estimated APC paid: $3,690

Funders: Agence Nationale de la Recherche, European Research Council