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United States Department of Agriculture

Agricultural Research Service

Title: Possible Overwintering Mechanism of Bluetongue Virus in Vectors

Authors
item White, David
item Wilson, William
item Blair, Carol - COLORADO STATE UNIVERSITY
item Beaty, Barry - COLORADO STATE UNIVERSITY

Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: October 27, 2003
Publication Date: October 27, 2003
Citation: White, D.M., Wilson, W.C., Blair, C.D., Beaty, B.J. 2003. Possible overwintering mechanism of bluetongue virus in vectors. [abstract]. OIE Symposium on Bluetongue Virus, Taormina, Italy. p. 40.

Interpretive Summary: Bluetongue virus (BTV) causes an economically important arboviral disease in U.S. livestock. BTV is maintained in nature by cycling between vertebrate animals (domestic and wild ruminants) and the main U.S. vector Culicoides sonorensis, a biting gnat. However, the mechanism by which the virus survives the winter when the insects are dormant has eluded researchers for many years. Persistent infection of the vector insect was demonstrated by the detection of several BTV gene sequences in larvae collected from the field very early in the transmission season (overwintering larvae), supporting the hypothesis that the virus overwinters inside it's insect vector. In addition, the detection of gene sequences necessary for the infection of insect cells in the absence of those necessary for the infection of animal cells suggests that BTV may not require abundant expression of the outer coat genes to persist in the insect vector. This could explain the low rate of isolation of virus from insects.

Technical Abstract: Bluetongue virus (BTV) causes an economically important arboviral disease in U.S. livestock. BTV is maintained in nature by cycling between vertebrate animals (domestic and wild ruminants) and the main U.S. vector Culicoides sonorensis, a biting gnat. However, the mechanism by which the virus survives the winter when the insects are dormant has eluded researchers for many years. Persistent infection of the vector insect was demonstrated by the detection of several BTV gene sequences in larvae collected from the field very early in the transmission season (overwintering larvae), supporting the hypothesis that the virus overwinters inside it's insect vector. In addition, the detection of gene sequences necessary for the infection of insect cells in the absence of those necessary for the infection of animal cells suggests that BTV may not require abundant expression of the outer coat genes to persist in the insect vector. This could explain the low rate of isolation of virus from insects.

Last Modified: 12/19/2014