An ELISA assay using a combination of recombinant proteins from multiple strains of Orientia tsutsugamushi offers an accurate diagnosis for scrub typhus

Table 2 List of different criteria to determine the performance of ELISA for diagnosis of scrub typhus

Criteria used to determine ST cases^a	Patient is considered ST	If ELISA IgG or IgM OD is^b
		≥ cutoff	< cutoff
1. IgG or IgM or both ≥400 or 2. 4-fold increase in IgG or IgM titer; or 3. PCR positive	Positive	TP	FN
Otherwise	Negative	FP	TN

^aIf IFA or PCR test results meet any of the criteria, the patient is considered ST positive
^bThe ODs of IgG or IgM ELISA were compared with calculated IgG and IgM ELISA cutoff values, respectively. If it was ≥ cutoff, the ELISA is considered a true positive (TP). If it was < cutoff, the ELISA is considered a false negative (FN)

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