Table 1. Sensitivity and specificity of cpn60-targeted PCR assay compared to 16S–23S PCR.

	P1/Tint PCR results
cpn60 PCR resultsa	positive	negative	Total
positive	114	39	153
negative	9	30	39
total	123	69	192
		95% CIb
cpn60 PCR sensitivity	0.927	0.046
cpn60 PCR specificity	0.435	0.117

Positives and negatives were defined by the results of the P1/Tint assay and the corresponding numbers of positive and negative samples identified by the cpn60-targeted assay are indicated [34]. The sensitivity of the cpn60 PCR using P1/Tint as a gold standard was 0.927 (114 positives of 123), with a 95% confidence interval of 0.046. The specificity of the cpn60 PCR using P1/Tint as a gold standard was 0.435 (30 negatives of 69), with a 95% confidence interval of 0.117.

^aassayed using primer set H279p/H280p.

^bCI, confidence interval.