Table 1.
Sensitivity and specificity of prereaction detection using nonspecific SYBR safe indicator and postamplification detection using specific AuNP-LAMP probes and quantitative dPAD in single LAMP assay to detect Leishmania DNA among patients with asymptomatic leishmaniasis.
| LAMP methods | No. (n) of samples with nested PCRa | (%) Sensitivity (95% CI) | (%) Specificity (95% CI) | (%) PPV (95% CI) | (%) NPV (95% CI) | |
|---|---|---|---|---|---|---|
| Positive | Negative | |||||
| Prereaction detection | ||||||
| Fluorescent closed tubeb | 95.5 (77.2–99.9) | 96.9 (83.8–99.9) | 95.5 (77.2–99.9) | 96.9 (83.8–99.9) | ||
| Positive | 21 | 1 | ||||
| Negative | 1 | 31 | ||||
| Postamplification detection | ||||||
| Colorimetric precipitate AuNP-LAMP probesc | 95.5 (77.2–99.9) | 100.0 (89.1–100.0) | 100.0 (83.9–100.0) | 97.0 (84.2–99.9) | ||
| Positive | 21 | 0 | ||||
| Negative | 1 | 32 | ||||
| Postamplification detection | ||||||
| Distance-based paper device (dPAD)d | 95.5 (77.2–99.9) | 100.0 (89.1–100.0) | 100.0 (83.9–100.0) | 97.0 (84.2–99.9) | ||
| Positive | 21 | 0 | ||||
| Negative | 1 | 32 | ||||
aTotal number of positive results was based on nested PCR (reference standard method).
bSYBR safe initially mixed in the reaction before salt induction of postamplification detection was used as a fluorescent indicator for qualitative screening.
cGold nanoparticle was used as a color and precipitate indicator for specific evaluation.
dMeasurement of fluorescent migratory distance was used to semi-quantify the LAMP amplicons.