ARS | Publication request: Domestic cattle as a non-conventional amplifying host of vesicular stomatitis New Jersey virus

Submitted to: Medical and Veterinary Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 27, 2010
Publication Date: December 6, 2010
Citation: Smith, P.F., Howerth, E.W., Carter, D., Gray, E.W., Noblet, R., Smoliga, G.R., Rodriguez, L.L., Mead, D.G. 2010. Domestic cattle as a non-conventional amplifying host of vesicular stomatitis New Jersey virus. Medical and Veterinary Entomology. Available:[doi:10.1111/j.1365-2915.2010.00932.x].

Interpretive Summary: Vesicular stomatitis is an insect-transmitted viral disease affecting livestock in the Western United States every 8-10 years. The disease clinical presentation resembles that of foot-and-mouth disease (FMD) a devastating disease of cattle and pigs. Horses are also affected during these epidemics causing significant loses to the horse industry due to quarantine and cancellation of equestrian events. The mechanisms of transmission and source of virus for insect infection are not well understood since virus is not usually present in the blood of infected vertebrates hosts such as cattle. In this manuscript we tested the ability of cattle to serve as amplifying and maintenance hosts for vesicular stomatitis New Jersey virus (VSNJV). We demonstrated two situations where cattle can serve as a source of VSNJV to black flies: serving as substrate for horizontal transmission between infected and non-infected black flies while co-feeding on the same host or by infected cattle serving as source of infection. Transmission rates between infected and non infected flies ranged from 0-67 percent. Uninfected flies physically separated from infected flies by up to a distance of 11 cm were able to acquire virus during feeding though the rate of transmission decreased as distance between infected and uninfected flies increased. Acquisition of VSNJV by uninfected flies feeding on initial inoculation sites at 24 and 48 hr post-infection (PI) both in the presence and absence of vesicular lesions was detected. This research provides valuable information to devise effective strategies for prevention and control of VSV transmission during epidemics in the U.S.

Technical Abstract: The role of vertebrates as amplifying and maintenance hosts for vesicular stomatitis New Jersey virus (VSNJV) remains unclear. Livestock have been considered dead-end hosts because detectable viremia is absent in VSNJV-infected animals. We demonstrated two situations where cattle can serve as a source of VSNJV to Simulium vittatum (Diptera: Simuliidae): by serving as substrate for horizontal transmission among co-feeding black flies, and as a source of infection to uninfected black flies feeding on sites where VSNJV-infected black flies previously fed. Observed cofeeding transmission rates ranged from 0-67 percent. Uninfected flies physically separated from infected flies by up to a distance of 11 cm were able to acquire virus during feeding, though the rate of transmission decreased as distance between infected and uninfected flies increased. Acquisition of VSNJV by uninfected flies feeding on initial inoculation sites at 24 and 48 hr post-infection (PI) both in the presence and absence of vesicular lesions was detected.