Table 1.

Sensitivity and specificity of the SQ and CryptoPS assays for detection of CrAg in frozen-thawed plasma from HIV-seropositive patients with a CD4 count of <100 cells/μl compared to a reference lateral flow assay

Statistic	SQ assay	95% CI	CryptoPS assay	95% CI
Sensitivity (%)	98.33	91.06–99.99	90	79.49–96.24
Specificity (%)	100	97.28–100	94.1	89.5–97.9
Positive likelihood ratio	>100		15.19	7.71–29.90
Negative likelihood ratio	0.02	0.00–0.12	0.11	0.05–0.23

Note: Cryptococcal antigen (CrAg) enzyme immune-assay (EIA) results for the 194 participants were positive for 58 and negative for 136. Compared to the EIA, the sensitivity and specificity of the semi-quantitative (SQ) qualitative results were 100% (58/58) and 99% (135/136) while Crypto PS had 91.4% (53/58) sensitivity and 93.4% (127/136) specificity.