Table 8.
Validity of Widal and Typhidot immunoassays as diagnostic tools in comparison with stool culture for the diagnosis of typhoid fever.
| Stool culture | p value | Sen | Spec | PPV | NPV | Accu | Kappa (95% CI) | Agreement (%) | ||
|---|---|---|---|---|---|---|---|---|---|---|
| Pos | Neg | |||||||||
|
| ||||||||||
| Typhidot-IgM | ||||||||||
| Pos | 70 | 47 | 1 | 0.823 | 0.598 | 1 | 0.860 | 0.660 | 70.26 | |
| Neg | 0 | 219 | <0.0001 | 0.948–1.00 | 0.772–0.867 | 0.536–0.687 | 0.983–1.00 | 0.818–0.895 | 0.575–0.744 | |
|
| ||||||||||
| Widal | ||||||||||
| Pos | 69 | 90 | 0.985 | 0.661 | 0.434 | 0.994 | 0.729 | 0.433 | 51.54 | |
| Neg | 1 | 176 | <0.0001 | 0.923–0.999 | 0.601–0.718 | 0.392–0.476 | 0.961–0.999 | 0.678–0.776 | 0.358–0.522 | |
PPV: positive predictive value; NPV: negative predictive value; Pos: positive; Neg: negative; Accu: accuracy; Sen: sensitivity; Spec: specificity; IgM: immunoglobulin M.