Hantaviruses are a genus of viruses carried by mice, rats, and voles and transmitted to us by breathing air contaminated by droppings, urine, or saliva. The first of these viruses to be isolated, in 1976, was Hantaan virus, the one that causes a bleeding disease called Korean hemorrhagic fever, encoutered during Korean war; it was named after the Han River in South Korea. Hantaan had infected some 2,500 U.S. troops, killing between 5 to 10 percent of them and was feared as a potential biological warfare agent. The related Seoul virus causes a similiar but less severe fever, and probaly it is carried by common rats, is found everywhere. Puulmala virus, carried by voles, is found most often in Scandinavia and Western Europe. They all cause their victim's cappilaries to leak blood, leading to the failure of crucial organs before the immnue system can counterattack.
In 1993, the genus gained fresh notoriety when a newly recgonised member was blamed for the deaths of thirty-two people out of fifty-three cases. primaly in the Four Corners region of the southwestern United States. Press attention focused on sudden fatalities among young, otherwise healthy Navajo Indians who suffocated after their lungs rapidly filled up with plasma from damaged pulmonary blood vessels. Within a month after the first death, the Epidemic Intelligence Service of the Centers for Disease Control had identified a "new" hantavirus that they called the Mureta Canyon virus after a nearby geographic feature on the Navajo reservation ----- thereby offending the Navajos, who prefered to memerialize the canyon as the scene of a Spanish masscare (the phatogen was renamed as Sin Nombre, or no-name virus). The American bug, which might have a fatality rate more than ten times higher than Hantaan, had been living for untold ages in deer mice ( Peromyscus maniculatus, a ubiquitous North American field rodent ), probably emerging from time to time to infect humans according to ecological whimsy. Traditional Navajo medicine men reported similiar outbreaks during deer mouse infestions in 1918 and 1933. Indeed, Navajo legends recommended the burning of clothes soiled by mice.
Ninety-nine cases and fifty-one deaths from hantavirus pulmonary syndrome, as the disease is now known, had been confirmed in twenty-one states by the end of 1994, mostly in Arizona , New mexico, and Colorado. After HIV and rabies, hantavirus would thus be the third most lethal virus ever found in the United States. Yet, with closer study, many of the cases have resisted being associated beyond all doubt with exposure to rodents or even to the virus itself, leading scientists to wonder whether still unknown factors are involved. A minority of the Four Corners cases, for example, were absolutely linked to Sin Nombre.
In January 1994, a twenty-two-year-old Rhode Island man died from this disease, though he had not traveled outside the Northeast for two months. Three possible sites of infection, all in the New York state, were established but not proved: an old warehouse in Queens that he had cleaned, a vacation house on Shelter Island, and his family home on Long Island.
In late 1994, the virus was confirmed in the case of a hiker in his late mid-sixties who had hospitalized in June 1993 after sleeping in rodent-infested shelter along the Appalachian Trail in Virginia ( he survived serious lung, kidney, and liver complications). There is no specific treatment for hantavirus infection. Scientists believe that germ will eventually be found throughout North America, threathening humans whenever rodent populations impinge on where we live.