1a.Objectives (from AD-416)
The objective of this agreement is to investigate the pathogenesis of Vesicular Stomatitis Virus (VSV) in livestock infected through insect bite and to better understand the ecology and epidemiology of this virus in natural transmission cycles.

1b.Approach (from AD-416)
The cooperator has expertise in black fly biology (Simulium vittatum) and Vesicular Stomatitis Virus (VSV) vector transmission, has developed a series of methodologies to evaluate insect transmission to livestock species, as well as insect-to-insect virus tansmission in various laboratory and livestock species. The University of Georgia (UGA) has an established colony of black flies and can provide them for pathogenesis studies at PIADC. ARS-PIADC has developed a cattle model to study VSV pathogenesis that allows tracking viral infection and host response in-vivo using RT-PCR, microarrays, in-situ hybridization, immunohistochemistry and confocal microscopy. We will combine UGA's vector biology with ARS-PIADC's pathogenesis expertise to better undertand natural cycle of VSV infections.

3.Progress Report
In FY 2008, our objectives continue to be the investigation of the pathogenesis of Vesicular Stomatitis Virus New Jersey (VSNJV) in livestock infected via insect bite and to better understand the ecology/epidemiology of this virus in natural transmission cycles. The most significant accomplishment of FY 2008 was the generation of preliminary data to support our hypothesis that VSNJV transmission is facilitated by black fly saliva. The major accomplishments over the life of the project, including their predicted or actual impact include: 1.Validation of a bovine VSNJV coronary band scarification infection model. 2.Demonstrate black fly transmission of VSNJV to cattle. 3. Demonstrate VSNJV transmission from VSNJV-infected black flies to naive black flies co-feeding on the same host. These findings are significant since little is known regarding VSNJV transmission and infection (pathogenesis) in cattle. Our results represent the first report of clinical VS occurring in cattle following the bite of a VSNJV-infected black fly. Additionally, our results corroborate our earlier finding that virus can be transferred from infected to non-infected black flies co-feeding on the same host. This project has been monitored through email, conference calls and site visits from UGA staff to ARS, PIADC.