Location: Arthropod-borne Animal Diseases Research
Project Number: 3020-32000-011-11-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 15, 2017
End Date: Sep 14, 2020
Incursions of VSV from endemic regions of Mexico, occur sporadically in the southwestern U.S. and progress northward causing economic loses to the horse, cattle, and swine industries. The mechanisms of vector transmission and the ecological and environmental factors favoring these incursions and northern spread remain unclear. The objective of this work is to characterize emergent strains of vesicular stomatitis virus (VSV) in competent vector species to inform VSV epidemiology and outbreak risk assessments. Expected outcomes: 1. Virulence characterization including vector infection rate, replication rate, duration of infection and dissemination within vectors. 2. Transmission potential including viral escape of midgut barrier, dissemination to salivary glands and excretion in saliva. 3. Characterizing genetic factors that affect vector-borne transmission of emergent viral isolates. These studies will inform VSV epidemiology and provide critical information to predict potential establishment and spread of emergent strains in the U.S.
A multidisciplinary approach is necessary to address the issue of VSV emergence in the U.S. We hypothesize that there are biotic and abiotic factors that mediate the emergence and spread of VSV into the US. In collaboration with ARS, Kansas State University will conduct time-course infection studies to characterize virus-vector interactions with specific incursive VSV isolates and VSV-competent Culicoides midges. The emergent strains to be characterized will be selected based on phylogenetic analysis, conducted by Dr. Luis Rodriguez, Plum Island Animal Disease Center (PIADC), of recent outbreak isolates. Viral lineages that successfully emerged from Mexico and spread north in the U.S. will be compared with those that did not in order to determine whether the ability of the virus to infect a known U.S. vector significantly affected the ability of the virus to establish in the U.S. and spread.