Serological survey for antibodies against pestiviruses in Wyoming domestic sheep

Authors: SILVEIRA, SIMONE - University Of Rio Grande Do Sul; Falkenberg, Shollie; ELDERBROOK, MOLLY - University Of Wyoming; SONDGEROTH, KERRY - University Of Wyoming; Dassanayake, Rohana; Neill, John; Ridpath, Julia; CANAL, CLAUDIO - University Of Rio Grande Do Sul

Submitted to: Veterinary Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/12/2018
Publication Date: 4/13/2018
Citation: Silveira, S., Falkenberg, S.M., Elderbrook, M.J., Sondgeroth, K.S., Dassanayake, R.P., Neill, J.D., Ridpath, J.F., Canal, C.W. 2018. Serological survey for antibodies against pestiviruses in Wyoming domestic sheep. Veterinary Microbiology. 219:96-99. https://doi.org/10.1016/j.vetmic.2018.04.019.
DOI: https://doi.org/10.1016/j.vetmic.2018.04.019

Interpretive Summary: Diseases produced by bovine viral diarrhea virus (BVDV) -1, BVDV-2, border disease virus (BDV), and HoBi-like virus, cause substantial economic losses in cattle and sheep. Pestivirus control programs in the US have focused only on the control of BVDV-1 and 2 in cattle, but little information is available in other ruminant species. There is little information know about the presence of these viruses in sheep in the US, and if similar seroprevalence patterns exist between sheep and cattle since these two species will share pasture grazing space in different regions of the US. The present study surveyed the prevalence of antibodies against these viruses in domestic sheep from Wyoming, an important sheep producing state that shares grazing space with cattle. Sera from 500 animals were collected and examined for BVDV-1, BVDV-2, BDV and HoBi-like virus. Pestivirus seroprevalence varied between geographic regions within the state, with the west region of the state having the highest seroprevalence. The overall pestivirus prevalence of exposure rate was 5.6%. Antibodies were most frequently detected against BVDV-1, and no samples had predominant titers for BDV and HoBi-like pestivirus. The findings highlight and contribute to the understanding of the sheep pestivirus exposure and the similarities of seroprevelence patterns as compared to other ruminant species, namely cattle. Further, considerations should be made when determining which diagnostic tool to use for each virus, contact of other ruminant species such as wildlife that can contribute to transmission of these viruses and potential vaccination procedures should be taken into account in sheep production and would be necessary for a successful BVDV control program.

Technical Abstract: Pestiviruses including Bovine Viral Diarrhea Virus type 1 (BVDV-1), BVDV-2 and Border Disease Virus (BDV) have been reported in both sheep and cattle populations, together with an emerging pestivirus, HoBi-like virus. Pestivirus control programs in the United States have focused on the control of BVDV-1 and 2. The incidence of pestivirus infection in sheep in the United States and the risk of transmission between cattle and sheep populations are unknown. The aim of this study was to perform serological surveillance for pestivirus exposure in sheep from Wyoming, an important sheep producing state in the United States. To this aim, sera from 500 sheep, collected across the state of Wyoming (US) from 2015-2016, were examined by comparative virus neutralization assay against four species/types of pestiviruses: BVDV-1, BVDV-2, BDV and HoBi-like virus. Rates of exposure varied between geographic regions within the state. The overall pestivirus prevalence of exposure rate was 5.6%. Antibodies were most frequently detected against BVDV-1 (4%), and the highest titers were also against BVDV-1. Data from this study highlights understanding of the dynamics of the sheep pestivirus exposure and consideration of reference strains used for VN, transmission patterns, and potential vaccination history should be taken into account when designing sheep animal programs and for successful BVDV control program in cattle.