Rapid detection of severe fever with thrombocytopenia syndrome virus (SFTSV) total antibodies by up-converting phosphor technology-based lateral-flow assay.

In this study, an up-converting phosphor technology-based lateral-flow (UPT-LF) assay was developed to detect severe fever with thrombocytopenia syndrome virus (SFTSV) total antibodies rapidly and specifically. SFTSV recombinant N protein (SFTSV-rNP) was coated on analytical membrane for sample capture, up-converting phosphor (UCP) particles were used as the reporter, the luminescence emitted by UCP particles was converted to a measurable signal by a biosensor. The performance of UPT-LF assay was evaluated by testing 302 field serum samples by ELISA (enzyme-linked immunosorbent assay), Western blotting and UPT-LF assay. UPT-LF assay exhibited a lower detection limit than ELISA, and a satisfied level of agreement was exhibited by Kappa statistics (Kappa coefficient = 0.938). Considering Western blotting as the reference for comparison, the sensitivity and specificity of UPT-LF assay could reach 98.31% and 100%. UPT-LF assay showed no specific reaction with hantavirus total serum antibodies, which avoids the misdiagnosis of SFTSV from hantavirus that could cause similar clinical symptoms. UPT-LF assay was able to achieve acceptable results within 15 min and needed only 10 μL sample for each test. As a whole, UPT-LF assay is a candidate method for on-site surveillance of SFTSV total antibodies owing to its excellent sensitivity, specificity, stability, easy operation and for being less time consuming.