Hantavirus pulmonary syndrome (HPS) is an acute and often fatal infectious respiratory disease endemic to North and South America and has become a serious concern in Montana and across the United States. Hantavirus was first recognized in the U.S. in the spring of 1993 after a cluster of previously healthy individuals in the Four Corners area of New Mexico acquired an acute cardiopulmonary illness.
As of July, 2003, there had been some 340 confirmed cases of hantavirus pulmonary syndrome in the U.S., more than 20 of them in Montana. Of these, there had been 129 deaths, five in Montana. The nationwide fatality rate was just over 38 percent. By 2006 the CDC (Center for Disease Control) reported an increase in human cases of hantavirus pulmonary syndrome during January to March in 5 states. A total of 9 cases were reported, 6 of which occurred in Arizona and New Mexico; the others were reported in North Dakota, Texas, and Washington state. According to the CDC, 438 cases of infection (fatality rate, 34%) have been reported from 32 states since the condition was recognized in 1993.
HPS can occur after exposure to the Sin Nombre (Spanish for “No Name”) virus in rodent saliva or excreta, with the deer mouse (Peromyscus maniculatus) comprising the predominant reservoir. Most commonly, people get hantavirus pulmonary syndrome by inhaling airborne particles of urine, feces or saliva from infected rodents. It is also possible, although less common, for transmission to occur when dried materials contaminated by rodent feces are disturbed, directly introduced into broken skin, introduced into mucus membranes (including the eyes and nose), or possibly ingested in contaminated food or water. Very infrequently, people have become infected after being bitten by rodents. Infected rodents shed the virus in saliva, urine and feces for a period possible infection is not known. The virus can live for a few days in contaminated dirt and dust.There is no evidence of person-to-person transmission. Even after extended exposure to patients, health care workers and family members have not contracted the illness.
The disease typically begins with a fever followed by pulmonary edema within 72 hours of hospitalization, often leading to severe respiratory compromise. Lab findings include thrombocytopenia, presence of immunoblasts, and hemoconcentration. Although no treatment exists for the infection, the probability of survival increases with early recognition, hospitalization, and aggressive pulmonary/hemodynamic support. The CDC strongly encourages health providers to be aware of HPS symptoms and report suspected cases to their state health departments.