Four Corners region, southwestern United States
Sin Nombre hantavirus HPS · Four Corners (NM, AZ, CO, UT) · verified historical
Live interactive map of every documented hantavirus outbreak — explore in full at hantavirusmap.io.
hantavirusmap.io ↗
Summary
Cluster of unexplained adult respiratory distress syndrome cases first recognized in May 1993 among Navajo and other residents of the Four Corners region. CDC, Indian Health Service, and state health departments identified a previously unknown hantavirus by mid-June 1993 (ultimately named Sin Nombre virus) with the deer mouse (Peromyscus maniculatus) as primary reservoir. The outbreak was associated with abnormally high deer mouse populations following heavy 1992–1993 precipitation tied to El Niño. By the end of 1993, 48 HPS cases had been confirmed nationwide with 27 deaths; 33 of these cases (17 deaths) occurred in the Four Corners states.
Why this matters
Discovery of hantavirus pulmonary syndrome (HPS) and the first hantavirus species identified in the Americas. Established HPS as a distinct clinical syndrome from HFRS and triggered the modern era of New World hantavirus surveillance.
Sources
- T1 Tracking a Mystery Disease: The Detailed Story of Hantavirus Pulmonary Syndrome Centers for Disease Control and Prevention · 2026-05-07
- T1 Hantavirus Pulmonary Syndrome: A Clinical Description of 17 Patients with a Newly Recognized Disease New England Journal of Medicine / CDC EID · 2026-05-07