Table 1

Sensitivity, specificity, PPV, and NPV of typhoid fever diagnostic tests, using blood culture and a composite reference standard (blood culture and real-time PCR) as comparators

Test% (95% confidence interval)
SensitivitySpecificityPPVNPV
Blood culture
    Tubex77.3 (59.8–94.8)87.4 (84.5–90.4)0.221 (0.128–0.313)0.988 (0.978–0.998)
    TyphiDot95.5 (86.8–104)79.1 (75.4–82.7)0.174 (0.106–0.241)0.997 (0.992–1.00)
    TR-0210081.6 (85.1–78.1)0.200 (0.125–0.275)1
    Widal (titer, 160)86.4 (72.0–100.7)95.0 (93.0–96.9)0.442 (0.293–0.590)0.993 (0.986–1.001)
Blood culture plus PCR (composite reference standard)
    Tubex51.1 (36.8–65.4)88.3 (85.3–91.2)0.312 (0.208–0.415)0.946 (0.924–0.967)
    TyphiDot70.0 (52.4–79.5)80.1 (76.5–83.8)0.256 (0.178–0.334)0.958 (0.938–0.978)
    TR-0289.4 (80.5–98.2)85.0 (81.7–88.3)0.382 (0.291–0.473)0.987 (0.976–0.998)
    Widal (titer, 160)51.1 (36.8–65.4)95.8 (94.0–97.7)0.558 (0.410–0.707)0.950 (0.930–0.970)