Seroprevalence against Sin Nombre virus in resident and dispersing deer mice.

Through dispersal, deer mice (Peromyscus maniculatus) enter peridomestic settings (e.g., outbuildings, barns, cabins) and expose humans and other deer mouse populations to Sin Nombre virus (SNV). In June 2004, research on deer mouse dispersal was initiated at 2 locations in Montana. During the course of the study, over 6000 deer mouse movements were recorded, and more than 1000 of these movements were classified as dispersal movements. More than 1700 individual deer mice were captured and tested for SNV, revealing an average SNV antibody prevalence of approximately 11%. Most of the dispersing and antibody-positive individuals were adult males. Among the few subadult dispersing mice discovered during the study, none were seropositive for SNV. Our results suggest that dispersal rates are higher in high abundance populations of deer mice and that during peak times of dispersal, human exposure to SNV, which commonly occurs in peridomestic settings, could increase.