Comparative analysis of WNV detection methods (VecTest and qPCR), for West Nile surveillance in Michigan USA

Mosquito borne arboviral disease surveillance depends upon trapping mosquitoes and testing them for viruses using sensitive laboratory methods. However, various methods are applied by public health agencies depending upon expediency and cost. An example is the VecTest, an antigen/antibody-based testing system applied to ground up mosquitoes. The test can be implemented at the laboratory bench rapidly and without specialized equipment. Yet, preliminary data show that it is less sensitive than reverse transcription, quantitative PCR testing systems which require a more sophisticated laboratory to perform. This research compares VecTest to RT-qPCR methods to determine the comparative sensitivity and utility of the methods for disease surveillance, using three public health surveillance systems in Michigan as model systems for research.
Our results show that there no consistency among the three public health agencies, characterized by over and underreporting of West Nile virus. This can be largely attributed to the subjective nature of interpretation of the results by human eye.
This has implications on the successful surveillance of the disease as well as resource allocation in response to WNV outbreaks.
We find that while VecTest is informative, efficient and cost effective, there is need to have a secondary test to affirm the results if public health decisions are to be made.