Table 3. Comparison between rapid S. haematobium diagnostic tests for children (9–15 yr, boys and girls) enrolled in Chaani, Kinyasini, and Mwera schools (N = 140), and adults (≥16 yr, males) attending Chaani Health Centre (N = 47) on Unguja, Zanzibar: visual blood in urine (macro-haematuria); visual opacity (turbidity); albumin concentration (HemoCue, excreted urine-albumin levels); and urine-reagent strips (Hemastix, micro-haematuria).
| Method of diagnosis | Target population | Sensitivity (CI95) | Specificity (CI95) | PPV (CI95) | NPV (CI95) |
| Macro-haematuria (self assessed) | Schools | 15.7 (7.0–28.6) | 96.6 (90.5–99.3) | 72.7 (39.3–94.0) | 66.7 (57.8–74.7) |
| Health Centre | 9.1 (6.8–23.8) | 100.0 (86.3–100.0) | 100.0 (15.8–100.0) | 55.6 (40.0–70.4) | |
| Visual turbidity (bar code chart) | Schools | 70.6 (56.2–82.5) | 79.8 (69.9–89.6) | 66.7 (52.5–78.9) | 82.6 (72.9–89.9) |
| Health Centre | 72.7 (49.8–89.3) | 68.0 (46.5–85.1) | 66.7 (44.7–84.4) | 73.9 (51.6–89.8) | |
| Albuminuria (conc.>40 mg/L) | Schools | 74.5 (60.4–85.7) | 89.9 (81.7–95.3) | 80.9 (66.7–90.9) | 86.0 (77.3–92.3) |
| Health Centre | 31.8 (13.9–54.9) | 76.0 (54.9–90.6) | 53.8 (25.1–80.8) | 55.9 (37.9–72.8) | |
| Micro-haematuria (urine reagent strip) | Schools | 90.2 (78.6–96.7) | 86.5 (77.6–92.8) | 79.3 (66.7–88.8) | 93.9 (86.3–98.0) |
| Health Centre | 90.9 (70.8–98.9) | 68.0 (46.5–85.1) | 71.4 (51.3–86.8) | 89.5 (66.9–98.7) |
In all cases parasitological positivity by microscopy (eggs in urine) was the ‘gold standard’.
PPV = positive predictive value; NPV = negative predictive value; CI95 = 95% confidence interval.