Natural history of Sin Nombre virus infection in deer mice in urban parks in Oregon.

Sin Nombre virus (SNV), one of at least 45 hantaviruses described worldwide, is hosted by the deer mouse, Peromyscus maniculatus, a common species throughout most of North America. Herein, we describe general life-history characteristics of deer mice and the ways in which these factors relate to the incidence of SNV infections among populations of this host species in and around Portland, Oregon. In total, 3,175 deer mice were captured from October 2002 to September 2005. Transmission of SNV appears to be associated with male breeding behaviors, as more males and adults were infected than expected by capture rate; spring and summer had the highest infection prevalence, as well as scrotal male captures. Wounding rates between infected and uninfected deer mice were not different in any age or sex class. Capture rates were significantly and positively related to the interaction of temperature departure from normal, total precipitation, and number of clear days from two seasons previous (P=0.029), while infection prevalence was significantly and negatively related to the capture rate of juveniles from two seasons previous (P=0.029).