Development of rapid and inexpensive diagnostic kits for foot and mouthdisease and Rift Valley fever

Foot-and-mouth disease (FMD) is one of the most economically devastating vesicular diseases of livestock. Rapid detection of FMD virus (FMDV) infection is essential for prompt identification and prevention of the spread of an outbreak. We developed two rapid diagnostic kits for detection of FMDV based on a chromatographic strip test that can be used in the field by technicians. In one kit, FMDV antigen can be detected using specific colloidal gold-conjugated monoclonal antibodies (MAbs) to the viral RNA polymerase (P3D). In the second kit, IgG or IgM antibodies to FMDV are detected. Antibodies to the FMDV-P3D present in serum are bound to gold-conjugated protein A/G and then captured by baculovirus recombinant P3D. These immunochromatographic strip tests are inexpensive, easy to make, and would be reliable diagnostic tools for early detection of animals infected with FMDV.;Rift Valley fever virus (RVFV) is highly infectious to humans and animals. This virus is transmitted and maintained by numerous mosquito genera including several native to North America. RVFV has enormous potential to be used as a weaponized bioterrorist agent to cause illness and death in humans as well as devastating economic losses in the livestock industry; rapid, accurate and safe laboratory tools for the diagnosis of RVFV are urgently needed. We have developed an ELISA system based on the N protein of RVFV expressed in a baculovirus expression system. The recombinant N protein was abundantly produced in insect cell culture and adapted to be used as solid phase antigen for development of the ELISA. The authenticity of the recombinant RVFV N protein was confirmed by western blot using serum from mice vaccinated with the MP12 vaccine strain of RVFV. The N protein antigen was then used for an indirect ELISA and successfully tested for the detection of antibodies to the virus in mouse anti-RVFV-MP12 serum samples. This ELISA system will allow public health investigators to quickly diagnose RVF and study the epidemiology of this devastating disease.