Outbreak of Hantavirus Infection in the Four Corners Region of the United States in the Wake of the 1997-1998 El Nino-southern Oscillation

J Infect Dis. 2000 May;181(5):1569-73. doi: 10.1086/315467. Epub 2000 May 15.


Hantavirus cardiopulmonary syndrome (HCPS), a rodent-borne zoonosis, has been endemic in the Americas for at least several decades. It is hypothesized that the 1991-1992 El Niño-southern oscillation (ENSO) caused increased precipitation that allowed an increase in rodent population densities, thereby increasing the possibility of transmission to humans. The result was a 1993-1994 outbreak of the disease in the Four Corners states of the southwestern United States. A second strong ENSO occurred in 1997-1998, after a period of considerable public education about the risks of hantavirus infection that began during the 1993-1994 outbreak. The caseload of HCPS increased 5-fold above baseline in the Four Corners states in 1998-1999. Regions that had received increased rainfall in 1998 were especially affected. A large majority of the 1998-1999 case patients reported indoor exposure to deer mice. Hantavirus outbreaks can occur in response to abiotic events, even in the face of extensive public education and awareness.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Arizona / epidemiology
  • Colorado / epidemiology
  • Disease Outbreaks*
  • Hantavirus Infections / epidemiology*
  • Hantavirus Infections / physiopathology
  • Hantavirus Infections / transmission
  • Humans
  • Incidence
  • New Mexico / epidemiology
  • Peromyscus
  • Population Density
  • Rain
  • Utah / epidemiology
  • Weather*