Table 2.
Performance of direct stool diagnostic techniques in the detection of intestinal parasites
| Techniques | Positive cases | Sensitivity | NPV | Accuracy (%) | 95% CI | κ index* |
|---|---|---|---|---|---|---|
| Thin smear | ||||||
| Helminths | 17 | 73.9 | 90.7 | 87 | 0.76–0.98 | 0.814 |
| Protozoa | 32 | 94.1 | 96.1 | 97.1 | 0.92–1.0 | 0.955 |
| Total | 49 | 86.0 | 86 | 93 | 0.88–0.98 | 0.850 |
| FEC | ||||||
| Helminths | 21 | 91.3 | 96.1 | 95.7 | 0.89–1.0 | 0.942 |
| Protozoa | 34 | 100 | 100 | 100 | 1.0–1.0 | 1.0 |
| Total | 55 | 96.5 | 96.1 | 98.2 | 0.95–1.0 | 0.962 |
| CF | ||||||
| Helminths | 22 | 95.7 | 98 | 97.8 | 0.93–1.0 | 0.971 |
| Protozoa | 33 | 97.1 | 98 | 98.5 | 0.95–1.0 | 0.978 |
| Total | 55 | 96.5 | 96.1 | 98.2 | 0.95–1.0 | 0.962 |
| Kato-Katz | ||||||
| Helminths | 20 | 87.0 | 94.2 | 93.5 | 0.93–1.0 | 0.911 |
| Protozoa | NA | NA | NA | NA | NA | NA |
| Total | 20 | 35.1 | 43 | 67.5 | 0.57–0.78 | 0.333 |
| Mini-FLOTAC-ZnSO4 | ||||||
| Helminths | 23 | 100 | 100 | 100 | 1.0–1.0 | 1.0 |
| Protozoa | 28 | 82.4 | 89.1 | 91.2 | 0.83–0.99 | 0.860 |
| Total | 51 | 89.5 | 89.1 | 94.7 | 0.90–0.99 | 0.887 |
| Mini-FLOTAC-NaCl | ||||||
| Helminths | 22 | 95.7 | 98 | 97.8 | 0.93–1.0 | 0.971 |
| Protozoa | 19 | 55.9 | 76.6 | 77.9 | 0.67–0.89 | 0.626 |
| Total | 41 | 72.0 | 75.4 | 86 | 0.79–0.93 | 0.703 |
CF = centrifugal flotation; CI = confidence interval; FEC = formol-ether sedimentation; NA = not applicable; NPV = negative predictive value. Combined results from all diagnostic techniques were considered as “gold standard.”
*
κ measures were interpreted as follows: < 0, poor agreement; 0–0.20, slight agreement; 0.21–0.40, fair agreement; 0.41–0.60, moderate agreement; 0.61–0.80, substantial agreement; and 0.81–1.0, almost perfect agreement.