ABSTRACT
The genus Hantavirus, family Bunyaviridae, contains more than 20 viruses, including those causing hemorrhagic fever with renal syndrome (HFRS) or hantavirus pulmonary syndrome (HPS) [1]. Each distinct hantavirus is generally carried by a single rodent host species, although spillover of viruses into other rodents and rare species-jumping events has been observed [2-5]. Genetically closely related rodents carry closely related hantaviruses, reflecting coevolution or cospeciation of hantaviruses and rodents, probably over hundreds of thousands of years [3,6]. Because of this close association of the viruses and hosts, hantaviral diseases are geographically restricted to the range of the rodent carrying a particular virus. For this reason, HFRS, which is caused by hantaviruses carried by Old World rodents, is found in the eastern hemisphere, whereas HPS, which is caused by viruses carried by New World rodents, is found in the western hemisphere. An exception to this generality is Seoul virus, an etiologic agent of HFRS, carried by rats (Rattus norvegicus or Rattus rattus). Although rats are native to the Old World they, along with Seoul virus, have been distributed worldwide over the past few centuries, mostly as passengers on cargo ships.
