Types of Hantavirus

All disease-causing hantaviruses sit in the genus Orthohantavirus, within the family Hantaviridae. The genus was renamed from "Hantavirus" in 2017, when bunyaviruses were reorganized into their own taxonomic order, Bunyavirales. Thirty-seven species are currently recognized.

Virions are enveloped and usually spherical, though oval, pleomorphic, or tubular shapes occur, ranging from about 70 to 350 nanometers across. Each carries three single-stranded, negative-sense RNA segments (large, medium, and small) along with Gn and Gc spike glycoproteins studded across the envelope.

Found across Africa, Asia, and Europe: Hantaan virus is the most common cause of severe HFRS in East Asia. Seoul virus is carried by brown rats and found nearly worldwide as a result, generally causing milder disease and accounting for a large share of HFRS cases globally. Puumala virus dominates in northern Europe and typically causes a mild form of HFRS known as nephropathia epidemica. Dobrava-Belgrade virus severity varies by genotype, with some strains among the most lethal hantaviruses known.

Found in the Americas: Sin Nombre virus, carried by the deer mouse, was identified during the 1993 Four Corners outbreak in the southwestern United States and remains the leading cause of HPS in North America. Andes virus circulates in South America and is notable as the only hantavirus with documented person-to-person transmission.

As a general pattern, each hantavirus species is tied to a single primary rodent reservoir species. That's why the geographic range of a given hantavirus tends to track the range of the rodent that carries it, rather than spreading independently of its host.