The evolution and emergence of hantaviruses

•Biodiversity surveys have revealed additional mammalian hosts of hantaviruses.•Rodents, bats, and Soricomorpha (moles and shrews) are the most common hosts.•Hantavirus diversity results from cross-species transmission and co-divergence.•Hantaviruses have likely been associated with mammals for millions of years.•Many more mammalian hantaviruses remain to be discovered.

Hantaviruses are a major class of zoonotic pathogens and cause a variety of severe diseases in humans. For most of the last 50 years rodents have been considered to be the primary hosts of hantaviruses, with hantavirus evolution thought to reflect a process of virus-rodent co-divergence over a time-scale of millions of years, with occasional spill-over into humans. However, recent discoveries have revealed that hantaviruses infect a more diverse range of mammalian hosts, particularly Chiroptera (bats) and Soricomorpha (moles and shrews), and that cross-species transmission at multiple scales has played an important role in hantavirus evolution. As a consequence, the evolution and emergence of hantaviruses is more complex than previously anticipated, and may serve as a realistic model for other viral groups.