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Abstract & Introduction

Background

Materials & Methods

Results & Discussion

References

Appendices

VECTEST

In May 2003, Dr. Claude Baker and Ms. August Nelson were certified to use the VecTest on the IUS campus for the detection of West Nile Virus in mosquito populations collected in Clark, Floyd and Harrison counties. The following describes the VecTest and the protocol used on campus.

The VecTest is a West Nile Virus (WNV) Antigen Assay produced by Medical Analysis Systems, Incorporated. The VecTest West Nile Virus Antigen Assay is a rapid immunochromatographic assay intended for the qualitative determination of WNV antigen in infected mosquitoes. Results from this assay can enable public health teams to:

Assays which detect the disease-causing agents and pathogens in field populations of arthropods, such as mosquitoes, make it possible to monitor the spread of disease, to identify areas where there is risk of humans and other domestic animals contracting disease, and to more efficiently target arthropod control measures. The recent emergence of West Nile Virus (WNV) is the Western Hemisphere has prompted the development of several assays for the detection of West Nile antigen in vector species. Growth of the virus in cell culture and PCR-based molecular methods remain the standard for virus identification. These methods require many reagents and multiple steps in a lengthy procedure that must be performed using specialized instruments within the laboratory.

The VecTest WNV Antigen Assay uses monoclonal antibodies against WNV and the Flavivirus group to identify the presence or absence of viral antigen specific to WNV in mosquitoes. The VecTest WNV Antigen Assay is a rapid, one step wicking assay providing rapid results, ambient storage and requiring no specialized equipment.

Lack of a vaccine and the many unknowns concerning the transmission rate and involved vectors necessitate mosquito control measures as the only means of controlling the spread of the disease in human populations. The VecTest WNV Antigen Assay provides a time-efficient and cost-effective method of controlling the spread of West Nile Virus.

1. Place up to 50 female mosquitoes into a plastic culture tube provided in the VecTest kit.
2. Dispense 2.5 mL of Grinding Solution onto the mosquitoes and add four copper-coated ball bearings provided by the VecTest kit.
3. Vortex the capped tube for 1 minute at high speed until the mosquito pool is homogenized into a slurry. (A centrifugation step may be performed to remove excess mosquito debris before running the test).
4. Dispense 250 uL of mosquito homogenate into a conical tube provided, place the tube into the tube stand provided, and insert a test strip from the canister with the arrows pointing down. (Replace the desiccant cap on the canister to protect the remaining strips from moisture). WAIT 15 MINUTES FOR THE TEST TO BE COMPLETED.
5. Determine the test results by removing the test strip and comparing it to the pictorial sample provided on the back of the VecTest insert.
6. Autoclave hazardous waste and discard appropriately.