VIRUS-VECTOR-HOST INTERACTIONS OF ARBOVIRAL DISEASES OF LIVESTOCK
Location: Arthropod-Borne Animal Diseases Research
Title: The Dutch strain of BTV-8 in white-tailed deer
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 5, 2011
Publication Date: April 11, 2011
Citation: Drolet, B.S., Reister, L.M., Mecham, J.O., Wilson, W.C., Nol, P., Vercauteren, K.C., Ruby, T.C., Vanrijn, P.A., Bowen, R.A. 2011. The Dutch strain of BTV-8 in white-tailed deer. Meeting Abstract. Epizone: Science on Alert, the Netherlands, April 11-14, 2011.
Bluetongue virus (BTV), family Reoviridae, genus Orbivirus, contains ten double stranded RNA segments encoding at least ten viral proteins. Bluetongue (BT) is an arthropod-borne disease; transmission to ruminants, including cattle, sheep, goats, and deer species by bites of species of Culicoides. In 2006, BTV8\net06 (IAH collection nr. BTV-8 NET2006/04, Maan et al., 2008) invaded North-Western Europe resulting in the largest BT-outbreak ever recorded. This BTV-strain differs from other BTV-strains in many aspects; competent vector(s), transplacental and oral transmission, and severity in cattle (Meiswinkel et al., 2007, Dijkstra et al., 2008, Backx et al., 2007, 2009). To determine the susceptibility of USA white-tailed deer (Odocoileus virginianus) to the European strain of BTV8\net07 (IAH-collection BTV-8 NET2007/01), eight BTV-seronegative deer were injected subcutaneously in the neck and intradermally in the inner left leg. Two deer were sham inoculated to serve as uninfected controls and housed with infected animals to verify the inability of this virus to spread by direct contact transmission. Body temperatures and clinical signs were recorded daily. Periodic blood samples were analysed for BTV RNA with qRT-PCR, for BTV serum antibodies by cELISA, and for infectious virus by plaque assay. At necropsy, tissue samples were taken for histopathological examination and tested by qRT-PCR for viral RNA. Deer developed moderate to severe clinical disease from 8 to 15 days post inoculation (dpi). Peak vireamia by qRT-PCR was from 7-10 dpi with detectable virus titers observed as far out as 28 dpi in some deer. Antibody titers were detected by cELISA starting at day 6, peaked by day 10, and continued through the end of the experiment (day 28). These results suggest that if BTV8 is accidentally or intentionally introduced into the USA, considerable disease would be expected in USA white-tailed deer and they would serve as significant virus reservoirs.