Diagnostic utility of a loop-mediated isothermal amplification test for rapid detection of Babesia gibsoni in canine blood samples

Abstract

Tick-borne diseases caused by pathogens such as Babesia gibsoni are important causes of morbidity and mortality in dogs. Current molecular diagnostic tests typically require sample submission to centralised laboratory facilities, which can be costly and long turnaround times may delay the diagnosis and subsequent treatment decisions. Here, we evaluated an in-house isothermal nucleic acid amplification test (in-house INAAT) based on one-pot loop probe-mediated isothermal amplification (oLAMP), coupled with a qualitative lateral flow assay (LFA) readout, capable of detecting Babesia gibsoni at the point-of-care in 30 min. Diagnostic performance was assessed in 153 archived blood samples from dogs with suspected tick-borne disease, and results were compared with a reference quantitative PCR (qPCR) assay. The results of the in-house INAAT were fully concordant with those of the qPCR assay, yielding 100% (33/33) sensitivity [95% CI 89.6 – 100%], 100% (120/120) specificity [95% CI 96.9 – 100%], and overall accuracy of 100% [95 CI 97.6%-100%]. Inter-reader agreement was almost perfect (κ = 0.98), with agreement in 152/153 (99.3%) tests. The test evaluated in this study demonstrated complete agreement with qPCR for targeted molecular detection of Babesia gibsoni in archived whole blood samples. Prospective studies using freshly collected samples are required to confirm its performance under routine point-of-care conditions.