The incubation period of hantavirus pulmonary syndrome

In 1993 Sin Nombre virus was recognized as the cause of hantavirus pulmonar y syndrome (HPS) and the deer mouse (Peromyscus maniculatus) was identified as the reservoir host. Surveillance by the Centers for Disease Control and Prevention and state health departments includes investigation to determin e the likely site(s) and activities that led to infection, an environmental assessment of the home and workplace, and possibly rodent trappings at the se sites. As of December 31, 1998, there were 200 confirmed cases from 30 s tates (43% case-fatality ratio). The national HPS case registry was examine d to determine the incubation period of HPS. Review of 11 case-patients wit h well-defined and isolated exposure to rodents suggests that the incubatio n period of HPS is 9 to 33 days, with a median of 14-17 days. Case investig ations allow a better understanding of the incubation time of HPS and may d efine highrisk behaviors that can be targeted for intervention.