Analytical validation of the CSI-Dx® Tick-Borne Assay and the RAPID-Dx Bioinformatic Pipeline in Urine

Culture-based methods have been regarded as the gold standard of diagnosis for infectious diseases (Laupland and Valiquette, 2013) and used as an essential tool in determining treatment regimens. However, these methods can take up to 96 hours to identify a pathogen and determine its susceptibility to antibiotics (Afshari et al., 2012). Some organisms, such as the causal agent of Lyme disease, B. burgdorferi, require special media and may take much longer to grow to detectable levels, if they grow at all (Schutzer et al., 2019). Factors that decrease the efficacy of culture-based methods include previous antibiotic treatment, growth media requirements that can be difficult or impossible to replicate, poor sample quality or preprocessing, low microbial load, and minor infection severity (Fenollar et al., 2006; Mancini et al., 2010; Afshari et al., 2012; Blauwkamp et al., 2019). Such methods fail to identify a pathogen as often as 50% of the time (Srinivasan et al., 2015). Situations where culture- based methods fail to identify pathogenic organisms in cases involving infection (culture- negative infections), have been shown to increase the risk of further complications due to uncertainties involving identification of pathogen(s) and associated resistances, which can delay the proper treatment required.