Evaluation of reverse transcription loop‐mediated isothermal amplification assay for the detection of severe fever with thrombocytopenia syndrome in clinical laboratories: A single‐center study

Abstract

AbstractSevere fever with thrombocytopenia syndrome (SFTS) is an acute infectious disease prevalent in East Asia with a high mortality rate (5%–30%). Reverse transcription loop‐mediated isothermal amplification (RT‐LAMP), a rapid nucleic acid‐based diagnostic technique, is a useful alternative for the clinical diagnosis of SFTS, particularly in resource‐limited hospitals or rural clinics in SFTS virus‐endemic regions. However, the actual clinical sensitivity and specificity of RT‐LAMP remain unclear. This study evaluated the field application of RT‐LAMP. This prospective field study included 130 patients with laboratory‐confirmed SFTS from Yantai, Shandong Province, China. Two sets of RT‐LAMP primers were validated, and one set of RT‐LAMP assays was optimized for field detection. Nucleic acids of serially collected serum/plasma samples were identified using quantitative reverse transcription polymerase chain reaction (RT‐qPCR) and RT‐LAMP. In laboratory tests, we optimized the detection time of primer set 2 for the RT‐LAMP to 60 min. Notably, the onsite testing of 279 plasma samples from patients with SFTS revealed that the sensitivity and specificity of the test were 81.9% and 96.3%, respectively. We also analyzed samples with different durations of the disease, and our study showed that the sensitivity of RT‐LAMP detection at the beginning of admission was 89.92%. Univariate analysis showed that the detection rate of RT‐LAMP was similar to that of RT‐qPCR in the first 5 days of the disease course and was lower than that of RT‐qPCR on Days 6 and 14–15 of the disease course. The positive detection rate in patients aged ≥ 65 years was significantly higher than that in younger age groups. RT‐LAMP is a simple, suitable, and rapid clinical detection method of SFTS onsite screening. It is more suitable for screening patients in the early stages of the disease and analyzing samples obtained from patients aged ≥ 65 years before the 6th day of the disease course.