Molecular Biology of Hantaviruses

Abstract

The genus Hantavirus includes several of the most significant human patho-gens in the family Bunyaviridae. Certain hantaviruses are known to cause such deadly illnesses as hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). Unlike viruses in other genera, hantaviruses are not transmitted by arthropods, but instead, persistently infect rodents and are transmitted in infectious aerosols of the animals’ excreta. A wide array of antigenically and genetically distinct hantaviruses have been detected in numerous rodent species throughout the world (Lee and van der Groen, 1989; Chu et al., 1994; Liang et al., 1994; Xiao et al., 1994). Among the hantaviruses described to date at least nine antigenically and genetically distinct viruses have been propogated in cell culture. HTN, Seoul (SEO), Puumala (PUU), and Dobrava (DOB) viruses have all been incrimi-nated in HFRS, and Sin Nombre (SN)⋆ and Black Creek Canal (BCC) viruses are linked to HPS. Prospect Hill (PH), Thailand (THAI), and Thottapalayam (TPM) viruses are not known to cause human disease. Interestingly, serologically distinct viruses are usually isolated from different rodent species. Thus, most viruses closely related to HTN virus have been isolated from Apodemus agrarius (striped field mice) and those most similar to SEO, PUU, DOB, and PH viruses from Rattus norvegicns (domestic rats), Clethrionomys glareolus (bank voles), Apodemus flavicollis (yellow-necked mouse), and Microtus pennsylvanicus (meadow voles), respectively. Two hantavirus isolates from Thailand, from Bandicota (bandicoot) or Rattus (Elwell et al., 1985), can be distinguished from SEO virus by PRNT (Chu et al., 1994). An Indian isolate from Suncus (tree shrew), TPM virus (Carey et al., 1971), the most unique hantavirus isolated to date, does not cross-react with other hantaviruses by PRNT (Chu et al., 1994), and has a clearly different genetic lineage (Xiao et al., 1994). The primary rodent host of SN virus is Peromyscus maniculatus (deer mouse) and that of BCC virus, Sigmodon hispidus (cotton rat) (Chapman and Khabbaz, 1994; Childs et al., 1994; Nerurkar et al., 1994; Ravkov et al., 1995; Turell et al., 1995). A number of other hantaviruses that appear genetically distinct, but have not yet been isolated in cell culture include El Moro Canyon (ELMC), Rio Segundo (RIOS), and New York-1 (NY-1)⋆ viruses in the U.S. (Hjelle et al., 1994; Song et al., 1994; Hjelle et al., 1995), and Tula (TUL) virus in Europe (Plyusnin et al., 1994).