Optimal cutoff titers for indirect immunofluorescence assay for diagnosis of scrub typhus

Abstract

We determined the optimal cutoff titers in admission and convalescent-phase samples for scrub typhus indirect immunofluorescence assay using Bayesian latent class models. Cutoff titers of>1:3,200 in an admission sample or of a>4-fold rise to>1:3,200 in a convalescent-phase sample provided the highest accuracy (sensitivity, 81.6%; specificity, 100%).