EVALUATION OF RIFT VALLEY FEVER DIAGNOSTIC TESTS FOR USE IN A DIVA CONTROL STRATEGY
Arthropod-Borne Animal Diseases Research
2012 Annual Report
1a.Objectives (from AD-416):
1. To determine what time point post RVF infection and in which samples (blood, saliva etc.) are these assays effective, and 2.) To evaluate the compatibility of these diagnostic RVF tests with a DIVA control strategy which will be determined via comparison of sheep vaccinated with commercial or candidate RVF vaccines with wild-type infected animals. These studies may include evaluating the ability of diagnostic assays to detect infectious virus, viral antigen/s and virus-specific nucleic acids in insect insects.
1b.Approach (from AD-416):
This project will utilize the expertise of three cooperative institutions to provide the experimental validation of safe (not contaminated with live RVFV) diagnostic tools that could be distributed to regional Bio-Safety Level 2 (BSL-2) diagnostic laboratories for early detection. The project will also develop and provide the initial evaluation of a novel SERS based assay systems for viral diagnosis. ARS has and will develop molecular diagnostic tests for RVFV nucleic acid. ARS has and will develop immunological diagnostic assays base on BLS-2 generated diagnostic reagents. ARS will assist and coordinate the evaluation of these assays through cooperators.
The objective of this project is to develop diagnostic tests that are compatible to potential DIVA control strategies and Rift Valley fever (RVF) infection models that could be utilized to evaluate them. The required authorizations were obtained to import the RVF vaccine strain MP-12 into Kansas State University’s Biosecurity Research Institute and to perform an infection study in this facility. The study provided an opportunity to safely test enhance biological safety standard operating material as well as generate biological samples for diagnostic test evaluation. The RVF Surface enhanced Raman Spectroscopy (SERS) assays (nucleic acid and antigen detection) for RVF was developed and multiplexed with the original prototype assays for WNV. Assays have been further modified to reduce background and formatted into triplex assay systems. The SERS development was performed under a subagreement #5430-32000-001-06S.