Table 3.
HIV testing algorithm performance per study site.
| Conakry, Guinea | Kitgum*, Uganda | Kitgum*’#, Uganda | Arua*, Uganda | Homa Bay, Kenya | Douala*, Cameroun | Baraka*, DRC | Baraka*’#, DRC | |
|---|---|---|---|---|---|---|---|---|
| Included in the study based on HIV status tested at site | ||||||||
| Total, n | 446 | 438 | 438 | 443 | 500 | 462 | 497 | 497 |
| Positive, n (%) | 222 (49.8) | 218 (49.7) | 216 (49.6) | 212 (47.9) | 223 (44.6) | 222 (48.1) | 226 (45.5) | 221 (44.5) |
| Negative, n (%) | 220 (49.3) | 220 (50.3) | 220 (50.2) | 231 (52.1) | 277 (55.4) | 230 (49.8) | 219 (44.1) | 220 (44.2) |
| Inconclusive, n (%) | 4 (0.9) | 0 (0) | 2 (0.2) | 0 (0) | 0 (0) | 10 (2.2) | 52 (10.5) | 56 (11.3) |
| Results based on reference standard | ||||||||
| Positive, n (%) | 222 (49.8) | 214 (48.9) | 214 (48.9) | 212 (47.9) | 224 (44.8) | 214 (46.3) | 221 (44.5) | 221 (44.5) |
| Negative, n (%) | 224 (50.2) | 222 (50.7) | 222 (50.7) | 230 (51.9) | 276 (55.2) | 247 (53.5) | 275 (55.3) | 275 (55.3) |
| Indeterminate n (%) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 1 (0.2) | 0 (0.0) | 1 (0.2) | 1 (0.2) | 1 (0.2) |
| Acute infection (%) | 0 (0.0) | 2 (0.5) | 2 (0.5) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) |
| Diagnostic performance of algorithm at study site | ||||||||
| Sensitivity % (95% CI) | 100 (98.3–100) | 96.2 (78.1–99.4) | 96.2 (78.2–99.4) | 89.5 (76.2–95.8) | 98.7 (96.1–99.7) | 100 (98.3–100) | 100 (98.3–100) | 100 (98.3–100) |
| Specificity % (95% CI) | 100 (98.3–100) | 99.8 (99.4–99.9) | 99.9 (99.6–100) | 99.8 (99.3–99.9) | 99.3 (97.4–99.9) | 98.3 (96.7–99.1) | 98.5 (95.7–99.5) | 99.9 (99.7–100) |
| PPV % (95% CI) | 100 (98.3–100) | 98.2 (95.3–99.5) | 99.1 (96.7–99.9) | 98.6 (95.9–99.7) | 99.1 (96.8–99.9) | 96.4 (93.0–98.4) | 97.8 (94.9–99.3) | 99.5 (97.5–100) |
| NPV % (95% CI) | 100 (98.3–100) | 99.1 (96.7–99.9) | 99.5 (97.5–100) | 98.3 (95.6–99.5) | 98.9 (96.9–99.8) | 100 (98.4–100) | 100 (98.3–100) | 100 (98.3–100) |
| False positive, n | 0 | 4 | 2 | 3 | 2 | 8 | 5 | 1 |
| False negative, n | 0 | 1 | 1 | 4 | 3 | 0 | 0 | 0 |
DRC: Democratic Republic of Congo.
*Adjusted results considering verification bias and excluding indeterminate results on-site and seroconverters by the reference algorithm.
#Algorithm using a simple confirmatory assay (ImmunoComb II HIV 1&2 CombFirm, Orgenics, Israel) with an alternative interpretation by Médecins sans Frontières.