Location: Arthropod-borne Animal Diseases ResearchTitle: Detection of bluetongue virus RNA in field-collected Culicoides spp. (Diptera: Ceratopogonidae) following the discovery of bluetongue virus serotype 1 in white-tailed deer and cattle in Louisiana Author
Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/5/2009
Publication Date: 3/31/2010
Publication URL: http://naldc.nal.usda.gov/download/41316/PDF
Citation: Becker, M.E., Reeves, W.K., Dejean, S.K., Emery, M.P., Ostlund, E.N., Foil, L.D. 2010. Detection of bluetongue virus RNA in field-collected Culicoides spp. (Diptera: Ceratopogonidae) following the discovery of bluetongue virus serotype 1 in white-tailed deer and cattle in Louisiana. Journal of Medical Entomology. 47(2): 269-273. Interpretive Summary: Biting midges spread viral diseases such as epizootic hemorhagic disease virus and bluetongue, which are diseases of wildlife and domesticated animals. This study in January 2006 until November 2007 collected 1,790 biting midges from three farms to look for infection. There were ten different species of midges which were grouped together to look for the presence of virus. Five groups tested positive for bluetongue (1.8% of the total). The species that were positive are common species and help identify other species of midges that may be disease vectors. The bluetone viruses detected were serotypes 17 and 13, both of which are found in the United States.
Technical Abstract: In November 2004, bluetongue virus (family Reoviridae, genus Orbivirus, BTV) serotype 1 (BTV-1) was detected for the first time in the United States from a hunter-killed deer in St. Mary Parish, LA. In 2005, sera surveys were conducted on three cattle farms near the area where the deer was found, and BTV-1-seropositive cattle were found on two of the three farms; in 2006, sera surveys from the cattle on the three farms did not detect any BTV-1-positive animals. The purpose of this study was to survey ceratopogonid populations at the three farms and test field-collected specimens for the presence of BTV and epizootic hemorrhagic disease virus (family Reoviridae, genus Orbivirus, EHDV). Miniature CDC light traps and New Jersey traps were used to capture ceratopogonids on the three farms from January 2006 through November 2007. In total, 3,319 ceratopogonids were captured, including 1,790 specimens of 10 different species of Culicoides. IR-RT-polymerase chain reaction (PCR) was performed to screen for BTV and EHDV in 264 pools representing 2,309 specimens collected at the farms. All positive samples were sequenced for serotype determination. Five pools of 275 (1.8%) were positive for BTV. Pools of four species of Culicoides were found to be positive: Culicoides crepuscularis (Malloch), Culicoides debilipalpis Lutz (two pools), Culicoides haematopotus Malloch, and Culicoides furens (Poey). The amplicons of the positive specimens were sequenced and found to be identical to both BTV-17 and BTV-13. During our study, no BTV-1 transmission was detected in cattle, and no BTV-1 was detected in specimens of ceratopogonids.