Hantavirus Pulmonary Syndrome (cont.)

The first recognized outbreak of HPS was noted in 1993 in the "Four Corners" area of the U.S. where the states of Arizona, New Mexico, Colorado, and Utah meet. Two otherwise healthy young people, a Navajo Indian and his fiancée, suddenly became short of breath and died. This unusual situation triggered a review of deaths in the four states that resulted in identification of five other young people who recently died with similar breathing problems. During the next few weeks, additional people were found being treated in the same geographic area with similar pulmonary syndromes. Tissues from affected patients were sent to the CDC where researchers searched for causes and found a link among the patients; infection with a previously unknown type of hantavirus. Since other known hantaviruses (in Asia and Europe) were known to be transmitted to people by rodents, the researchers started trapping rodents during June to August 1993 to determine if the virus was associated with the animals. In November 1993, a rodent (a deer mouse) trapped by CDC researchers in a house where a person who developed the pulmonary syndrome lived yielded the previously unknown virus. In addition, army researchers soon isolated the same virus from an infected patient who also had exposures to mice. This new hantavirus was first termed Muerto Canyon virus, then Sin Nombre virus (SNV), and eventually simply hantavirus. The disease caused by this virus was termed hantavirus pulmonary syndrome (HPS). Further investigations suggested that other people had died from this infection in the past when autopsy tissue was found to contain the virus. When Navajo Indian medical traditions were studied, the Navajo medical culture apparently recognized the disease and had associated it with mice. The outbreak in 1993 probably occurred because environmental factors led to favorable survival and proliferation of mice; the mouse population was about tenfold greater in 1993 than in 1992 in the Four Corners area.

The most recent outbreak of HPS has occurred at Yosemite National Park, Calif., in 2012. The outbreak was linked to deer mouse dropping contamination in campsites (tent-cabins) used by tourists. At least three deaths have occurred and six others are recovering. Public-health officials have sent notices out to over 230,000 park visitors to warn them of potential exposure to hantaviruses as of mid-September 2012.

Source: MedicineNet.com
http://www.medicinenet.com/hantavirus_pulmonary_syndrome/article.htm