hantavirus, any of a genus (Hantavirus) of single-stranded RNA viruses that are carried by rodents and transmitted to humans when they inhale vapors from contaminated rodent urine, saliva, or feces. There are many strains of hantavirus. The first to be isolated (1976) was the Hantaan virus (from the Han River in South Korea, which also gives the species its name). Hantaan virus and its related strains, Seoul virus and Puulmala virus, cause Korean hemorrhagic fever (more correctly, hemorrhagic fever with renal syndrome), a condition in which the capillaries of the circulatory system begin to leak blood. Although some people with the disease are nearly asymptomatic, in others it can lead to shock, acute kidney failure, and, in 10% of cases, death.
A second disease, hantavirus pulmonary syndrome, was identified in the United States in 1993 and is caused by at least three strains of the virus. It is known to be carried by deer mice, white-footed mice, and cotton rats. This disease is much more deadly, causing flulike symptoms that can lead to fluid accumulation in the lungs and death. One of the pulmonary strains, the Sin Nombre virus (named for a Spanish massacre of Native Americans that occurred in the canyon where it was discovered), was the cause of a 1993 outbreak in the Four Corners area of the SW United States that killed 32 of 53 people known to have been infected. Hantavirus pulmonary syndrome occurs sporadically in North America, with roughly one third of those known to be infected dying from the disease. Outbreaks of a hantavirus strain that apparently can be spread from person to person occurred in South America in 1996 and 1997. There is no vaccination for pulmonary hantavirus. Treatment includes respiratory and hemodynamic support; the antiviral drug ribavirin has been effective in some cases.