Fig. 3

The field precision of the Kalon HSV-2 IgG ELISA. a Shows box plots that represent the range, interquartile range, and median Kalon index values for samples tested by all operators (n = 170). The star and pound signs represent inter-operator comparisons by the Wilcoxon rank-sum test. b Shows the correlation and variability in Kalon index values between operators and also presents the agreement of categorical results between operators as determined by the manufacturer’s index cut-offs (<0.9, negative; 0.9–1.1, indeterminate; >1.1 positive); (n = 170). c Depicts any sample that had a Kalon result that was discordant from other Kalon results by all operators (n = 183). The ^a indicates that these results were generated by Technologist-Sr. in South Africa