Leporipoxvirus

Leporipoxvirus is a genus of large, enveloped poxviruses in the family Poxviridae, subfamily Chordopoxvirinae. It currently comprises two species, Myxoma virus and Shope fibroma virus, both of which infect lagomorphs—especially rabbits—and are transmitted by arthropod vectors such as mosquitoes and fleas, as well as by close contact and fomites.

Genomes of Leporipoxviruses are large, linear double-stranded DNA, typically in the range of 160 to 170 kilobases and encoding hundreds of genes. Virions are brick-shaped and enveloped, roughly 200 nanometers in size, and replication occurs in the cytoplasm with virus-encoded transcription machinery, as is characteristic of poxviruses.

Clinical presentation and host range vary by species. Myxoma virus causes myxomatosis, a disease marked by mucopurulent conjunctivitis, swelling of the eyelids and face, and diffuse cutaneous nodules; mortality is high in naive rabbit populations. Shope fibroma virus commonly induces fibromas or tumor-like growths on the skin of rabbits, with disease severity influenced by strain and host factors. Both viruses can modulate host immune responses, affecting transmission dynamics and disease outcomes.

Epidemiology and control are region-specific. Myxomatosis was released in some areas as a biological control agent for wild rabbits, leading to changes in virulence over time. Control measures in domestic or captive settings include vaccination where available, vector management, and movement restrictions. Zoonotic risk is minimal; human infections are exceedingly rare and not considered a public health concern.