Hantaviruses are single-stranded, enveloped, negative sense RNA viruses in the Bunyaviridae family which can kill humans.

They normally infect rodents and do not cause disease in these hosts. Humans may become infected with hantaviruses through contact with rodent urine, saliva, or feces. Some strains of hantaviruses cause potentially fatal diseases in humans, such as hantavirus hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS)—also known as hantavirus cardiopulmonary syndrome (HCPS)— while others have not been associated with known human disease. HPS (HCPS) is a "rare respiratory illness associated with the inhalation of aerosolized rodent excreta (urine and feces) contaminated by hantavirus particles."