The bullet-shaped virus behind rabies is far more diverse than we once thought

Nature · Published 29 September 2026 Swipe more like this →

In short: Lyssavirus is a genus of RNA viruses known for causing rabies, but its true scope extends well beyond a single disease. With unique bullet-shaped structures and a complex evolutionary history, these viruses challenge our understanding of host origins and geographic distribution, revealing a hidden world of viral diversity.

The Lyssavirus genus, derived from the Greek word for rage, consists of enveloped, bullet-shaped virions measuring approximately 75 nm by 180 nm. Unlike many human-infecting viruses that exhibit cubic symmetry, these particles possess helical symmetry, forming cylindrical structures. Internally, they contain a negative-sense, single-stranded RNA genome of about 11 kb, which encodes five essential proteins: nucleoprotein N, phosphoprotein P, matrix protein M, glycoprotein G, and polymerase L. Replication occurs within the host cell cytoplasm, where the virus enters via clathrin-mediated endocytosis and exits through budding.

While the rabies virus is globally prevalent and infects most warm-blooded mammals, other lyssaviruses are far more specialized, often limited to specific geographic regions and host species. Phylogenetic analysis has categorized these into twelve known species, organized into four distinct phylogroups based on DNA sequence homology. West Caucasian bat lyssavirus stands out as the most divergent member, occupying its own unique phylogroup. Although bats are recognized as vectors for nearly all identified lyssaviruses—with the notable exception of the Mokola virus—recent findings of viral sequences in reptiles and amphibians have complicated the long-held theory that these viruses originated exclusively in mammals.

The origin of the genus remains a subject of active investigation. While Africa was historically considered the source due to high antigenic diversity, recent studies of 153 viruses collected between 1956 and 2015 point toward a Palearctic origin with 85% likelihood. Estimates for the most recent common ancestor are broad, ranging from roughly 4,000 to 166,800 years ago. Diagnostic methods have evolved significantly; while the direct fluorescent antibody test remains the gold standard as of 2018, newer real-time PCR-based assays, such as the TaqMan LN34, have demonstrated high sensitivity and specificity, offering a promising future for post-mortem diagnostics.

General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.

Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?

Related

• How a single virus mastered the art of evading our defenses
• Once clinical symptoms appear, the rabies virus is virtually 100% fatal for human beings.
• Why bats carry dangerous viruses without ever getting sick
• Marburg virus: A lethal hemorrhagic pathogen with a complex, century-long evolutionary history
• Rabies almost never forgives once symptoms begin
• Hawaii's macadamia industry may trace back to a single Australian tree
• Four lynx species—one climbed back from the brink
• After humans, no primate genus has spread as widely as the macaques
• Today's humble clubmosses had ancestors taller than a 12-storey building
• The macaroon is a global culinary chameleon with roots in medieval monastic kitchens.
• Chinese emperors ran express horse relays just to get lychees fresh
• Why do macaws eat dirt? It is not to neutralize toxins as once thought.

More in Organisms · More in Nature · Latest · A–Z · All topics