Detection of antibodies for serodiagnosis of plague and Hantavirus in wild rodent species

Rodents are a diverse and abundant group of mammals and important hosts of potentially fatal diseases like plague and Hantavirus Pulmonary Syndrome (HPS). High prevalence of Sin Nombre virus in deer mice increases the risk of... [ view full abstract ]

Rodents are a diverse and abundant group of mammals and important hosts of potentially fatal diseases like plague and Hantavirus Pulmonary Syndrome (HPS). High prevalence of Sin Nombre virus in deer mice increases the risk of HPS in humans. Plague outbreaks in prairie dogs, not only decimate prairie dogs and other rodent populations, but also pose a risk of spillover to humans. Therefore, it is important to screen wild rodents for antibodies against particularly virulent pathogens. Previous research focused on the detection of antibodies in laboratory mice and deer mice (Peromyscus spp.) but largely ignored other wild rodents. To validate serologic tests for different species, we compared total antibody detection using Protein-G and Protein-A/G enzyme immunoassays. Pooled blood samples were collected on Nobuto strips from deer mice, Northern grasshopper mice (Onychomys leucogaster), Ord’s kangaroo rats (Dipodomys Ordii), sagebrush voles (Lemmiscus curtatus) and Great Basin pocket mice (Perognathus parvus) on prairie dog colonies in the western United States, (Montana, South Dakota and Utah). All sites have a plague history and are located in Sin Nombre virus endemic regions. In addition, individual samples were tested for antibodies against Y. pestis antigens F1 and V and Sin Nombre virus nucleocapsid, using standard Protein-G and Protein-A/G assays. Protein-G and A/G gave significantly higher optical densities for kangaroo rat, chipmunk and grasshopper mice antibodies than for the antibodies of the other species. As expected, Sin Nombre seropositive deer mice were found in all regions, but plague antibodies were only detected on prairie dog colonies with a plague outbreak. This study showed that protein-G and A/G are also useful tools in less common wild rodent species, but prevalence data based on these proteins are not comparable among all species and should be interpreted cautiously.