Evaluation of a field-deployable reverse transcription-insulated isothermal PCR for rapid and sensitive on-site detection of Zika virus.
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.
['Carossino|Mariano|M|', 'Li|Yanqiu|Y|', 'Lee|Pei-Yu A|PA|', 'Tsai|Chuan-Fu|CF|', 'Chou|Pin-Hsing|PH|', 'Williams|Dennis|D|', 'Skillman|Ashley|A|', 'Frank Cook|R|R|', 'Brown|Grayson|G|', 'Chang|Hsiao-Fen G|HG|', 'Wang|Hwa-Tang T|HT|', 'Balasuriya|Udeni B R|UBR|']
D000818:Animals D009033:Culicidae D006801:Humans D019095:Point-of-Care Systems D012367:RNA, Viral D060888:Real-Time Polymerase Chain Reaction D012680:Sensitivity and Specificity D000071244:Zika Virus D000071243:Zika Virus Infection
Zika virus Insulated isothermal PCR POCKIT Point-of-need assay iiPCR