VECTOR COMPETENCE OF NORTH AMERICAN RIFT VALLEY FEVER DISEASE VECTORS
Arthropod-Borne Animal Diseases Research
2013 Annual Report
1a.Objectives (from AD-416):
The primary purpose of this agreement is to establish a general framework for cooperation and establish a mechanism by which ABADRU and USAMRIID will collaborate in research on the potential for Rift Valley Fever Virus transmission by arthropod vectors in North America. It also establishes a relationship whereby each research entity can call upon the other for advice concerning research methodology and directions.
1b.Approach (from AD-416):
A basic understanding of North American mosquito species susceptibility to Rift Valley fever virus infection and the subsequent interactions is needed in the event of an outbreak in the United States. To understand the propagation of Rift Valley fever in mosquitoes, three components will be examined in this agreement..
1)The effects of temperature on virus movement within the mosquito also known as the extrinsic incubation period;.
2)Whether there is reassortment of Rift Valley fever viral genes within mosquitoes; and.
3)The extent of transovarial transmission or vertical transmission of Rift Valley fever virus in North American mosquitoes from infected females to their offspring.
ABADRU received fifty samples Rift Valley Fever virus strains from USAMRIID deactivated in trizol on December 4, 2012 and the analysis of all samples was concluded on January 15, 2013. The samples included plaque picked viral isolates from both infected mosquitoes and hamsters of two known RVFV strains. Each RVFV genome segment was analyzed by a PCR-based melt temperature shift assay for all fifty samples. Due to low RNA concentrations, quality, and/or specificity, only half of these sample isolates were fully identified back to the parental strains.