Hantavirus in United States — 1993

The Four Corners outbreak that named hantavirus pulmonary syndrome

Overview

1993 is the year hantavirus pulmonary syndrome entered the global infectious-disease vocabulary. Between May and July of that year, public-health investigators in New Mexico, Arizona, Colorado, and Utah recorded a cluster of previously healthy adults — disproportionately young, fit, and Navajo — dying of an unexplained rapid-onset respiratory illness. By August, CDC's Special Pathogens Branch had identified a novel hantavirus in deer mice (Peromyscus maniculatus) from index households and, by November, had isolated the virus that would eventually be designated Sin Nombre. The 1993 case-fatality rate exceeded 50% — far higher than today's roughly 36–38% — reflecting how little was known about clinical management in the first weeks of the outbreak. The investigation drew on Navajo Nation traditional knowledge of past similar illness clusters, an ecology-driven trophic-cascade hypothesis tying mouse population booms to wet El Niño years, and rapid molecular-virology work that demonstrated the new agent shared family-level identity with the Old World Hantaan and Puumala viruses.

United States baseline

Highest case counts in western and southwestern states (NM, CO, AZ, CA). Sin Nombre virus is the dominant strain.

Source: CDC Hantavirus Surveillance

Relevant strain

References & primary sources

• MMWR 1993 — Outbreak of Acute Illness, Southwestern United States
• CDC — Hantavirus Surveillance

Other years tracked for United States