Hantavirus testing in small mammal populations of northcentral New Mexico

Abstract

In 1993, an outbreak of a new strain of hantavirus in the southwestern US indicated that deer mice (Peromyscus maniculatus) was the primary carrier of the virus. In 1993 and 1994, the Ecological Studies Team (EST) at Los Alamos National Laboratory surveyed small mammal populations in Los Alamos County, New Mexico, primarily for ecological risk assessment (ecorisk) studies. At the request of the Centers for Disease Control (CDC) and the School of Medicine at the University of New Mexico, EST also collected blood samples from captured animals for use in determining seroprevalence of hantavirus in this region due to the recent outbreak of this virus in the four-comers region of the Southwest. The deer mouse was the most commonly captured species during the tripping sessions. Other species sampled included harvest mice (Reithrodontomys megalotis), least chipmunk (Eutamias minimus), long-tailed vole (Microtus longicaudus), Mexican woodrat (Neotoma mexicana), and brush mouse (Peromyscus boylii). The team collected blood samples from tripped animals following CDC`s suggested guidelines. Results of the 1993 and 1994 hantavirus testing identified a total overall seroprevalence of approximately 5.5% and 4.2%, respectively. The highest seroprevalence rates were found in deer mice seri (3--6%), but results on several species were inconclusive; further studies will be necessary, to quantify seroprevalence rates in those species. Seroprevalence rates for Los Alamos County were much lower than elsewhere in the region.