Background: The recent emergence of Zika virus (ZIKV) in Brazil and its precipitous expansion throughout the Americas has highlighted the urgent need for a rapid and reliable on-site diagnostic assay suitable for viral detection. Such point-of-need (PON), low-cost diagnostics are essential for ZIKV control in vulnerable areas with limited resources.
Methods: We developed and evaluated a ZIKV-specific field-deployable RT-iiPCR reagent set targeting the E gene for rapid detection of ZIKV in ZIKV-spiked human and mosquito specimens, and compared its performance to the Center for Disease Control and Prevention (CDC) and Pan American Health Organization (PAHO) RT-qPCR assays targeting the E and NS2B genes, respectively.
Results: These assays demonstrated exclusive specificity for ZIKV (African and Asian lineages), had limits of detection ranging from 10 to 100 in vitro transcribed RNA copies/μl and detection endpoints at 10 plaque forming units/ml of infectious tissue culture fluid. Analysis of human whole blood, plasma, serum, semen, urine, and mosquito pool samples spiked with ZIKV showed an agreement of 90% (k = 0.80), 92% (k = 0.82), 95% (k = 0.86), 92% (k = 0.81), 90% (k = 0.79), and 100% (k = 1), respectively, between the RT-iiPCR assay and composite results from the reference RT-qPCR assays. Overall, the concurrence between the ZIKV RT-iiPCR and the reference RT-qPCR assays was 92% (k = 0.83).
Conclusions: The ZIKV RT-iiPCR has a performance comparable to the reference CDC and PAHO RT-qPCR assays but provides much faster results (~1.5 h) with a field-deployable system that can be utilized as a PON diagnostic with the potential to significantly improve the quality of the health care system in vulnerable areas.
Digital Object Identifier (DOI)
This study was funded by the College of Agriculture, Food and Environment (CAFE; grant number 1013172620) and the Maxwell H. Gluck Equine Research Center (GERC), Department of Veterinary Science (grant number 1215389410), University of Kentucky, Lexington, KY, USA.
The datasets from this study are available from the corresponding author upon request.
Carossino, Mariano; Li, Yanqiu; Lee, Pei-Yu A.; Tsai, Chuan-Fu; Chou, Pin-Hsing; Williams, Dennis; Skillman, Ashley; Cook, R. Frank; Brown, Grayson; Chang, Hsiao-Fen G.; Wang, Hwa-Tang T.; and Balasuriya, Udeni B. R., "Evaluation of a Field-Deployable Reverse Transcription-Insulated Isothermal PCR for Rapid and Sensitive On-Site Detection of Zika Virus" (2017). Gluck Equine Research Center Faculty Publications. 13.