2009 Annual Report 1a.Objectives (from AD-416) To characterize the susceptibility, pathogenesis, and virus-vector-host interactions in bluetongue virus (BTV) and vesicular stomatitis virus (VSV) animal infections. 1b.Approach (from AD-416) Animal infection studies will be conducted with vesicular stomatitis virus (VSV)and exotic bluetongue virus (BTV). The role of Culicoides sonorensis midge saliva in the ability of vesicular stomatitis virus to establish infection, replicate, and persist, will be examined using feral pigs. The physiological variations in VSV infected bats and guinea pigs and their affect on vector-host selection will be determined. The susceptibility of U.S. sheep and white-tailed deer to infection by exotic BTV serotype 8 will be determined. Bite rates, viral transmission, infection rates and pathogenesis will be measured by methods to include: clinical disease observations, virus isolation/plaque assay, polymerase chain reaction, ELISA, ethogram cataloging, videography, necropsy, histopathology, and immunohistochemistry. For all studies, scientists with complementary expertise from both parties will work together to obtain, analyze, and interpret the research data. 3.Progress Report The purpose of this project is to conduct animal infection studies with vesicular stomatitis virus and exotic bluetongue virus to determine disease susceptibility and the role of Culicoides sonorensis salivary proteins in viral infections of animals. For all studies, the scientists with complementary expertise from CSU and ARS work together to obtain, analyze, and interpret the research data. A permit for CSU to receive the European strain of bluetongue type 8 (EU-BTV-8) has been submitted, but not yet granted. Thus, no virus has been received and no master inoculum from sheep has been made. ADODR monitoring includes site visits, meetings, phone calls, and e-mail.