Methods: We utilized reverse transcription TaqMan® PCR chemistry to detect ZIKV RNA in contrived and clinical specimens. Primers and probes were designed to detect a portion of the envelope gene. Oligonucleotide design achieved specificity and sensitivity in detecting the current as well as other ZIKV strains. This assay utilizes the NucliSens easyMAG Total Nucleic Acid Extraction Platform. RNA is amplified and detected using the TaqPath™ qPCR Master Mix kit on an ABI 7500 SDS Instrument. Analytical performance characteristics were evaluated for each specimen type, and a clinical surveillance study was performed using clinical specimens collected from symptomatic and asymptomatic individuals in Colombia, South America.
Results: Analytical specificity was confirmed by the absence of signal with closely and distantly related pathogens that present similar signs and symptoms. The limits of detection in plasma and urine were 68 and 211 copies/mL, respectively. Of 153 clinical specimens tested, 23 were positive by qRT-PCR. Seven of these samples were present at sufficiently high titers to allow confirmation of the currently circulating ZIKV strain by Sanger sequencing. A total of 80 specimens from normal U.S. donors were found negative, and 50 samples from the surveillance study returned a negative result.
Conclusion: This laboratory-developed ZIKV qRT-PCR assay is a sensitive and specific test for detection of ZIKV RNA in plasma, serum, and urine specimens. The availability of this assay expands testing capabilities during the public health emergency, helping to meet public demand for ZIKV testing, which is currently only performed by public health laboratories and a limited number of commercial laboratories.
I. Caton, Viracor-IBT Laboratories: Employee , Salary
S. Kleiboeker, Viracor-IBT Laboratories: Employee , Salary
M. Altrich, Viracor-IBT Laboratories: Employee , Salary