Update: hantavirus pulmonary syndrome--United States, 1993.

A unique hantavirus has been identified as the cause of the outbreak of respiratory illness (hantavirus pulmonary syndrome [HPS]) first recognized in the southwestern United States in May 1993. The habitat of the principal rodent reservoir for this virus, Peromyscus maniculatus (deer mouse), extends throughout most of the United States except the Southeast. Through October 21, 1993, HPS has been confirmed in 42 persons reported to CDC from 12 states (Figure 1). This report summarizes major clinical, pathologic, and diagnostic findings in patients with this newly recognized syndrome; addresses the use of the investigational antiviral drug ribavirin; and presents revised screening criteria for national surveillance.