Table 6.
Determination of the limits of detection for Plasmodium spp. real time PCR targeting 18S genes in whole blood.
| Parasitemia (p/µl) | 100 | 20 | 10 | 1 | 0.5 | 0.25 | 0.12 | 0.06 | 0.03 | 0.015 | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Plasmodium spp. | P. falciparum | 26.4 ± 0.1 | 29.0 ± 0.3 | 30.0 ± 0.3 | 33.0 ± 0.7 | 34.0 ± 0.7 | 36.2 ± 1.2 | 37.2 ± NA | 39.0 ± NA | − | − |
| Positive wells | 3/3 | 3/3 | 3/3 | 5/5 | 4/5 | 3/5 | 1/5 | 1/5 | |||
| P. vivax | 25.5 ± 0.1 | 28.5 ± 0.2 | 29.0 ± 0.2 | 33.0 ± 0.5 | 34.4 ± 0.5 | 35.0 ± 0.5 | 36.3 ± NA | 36.0 ± 0.1 | 36.5 ± NA | − | |
| Positive wells | 3/3 | 3/3 | 5/5 | 5/5 | 4/5 | 3/5 | 1/5 | 3/5 | 1/5 | ||
| P. malariae | 32.3 ± 0.3 | 34.6 ± 0.4 | 34.2 ± 0.6 | 35.1 ± 0.8 | − | − | − | − | − | − | |
| Positive wells | 3/3 | 3/5 | 5/5 | 2/5 | |||||||
| P. ovale | 28.0 ± 0.3 | 30.0 ± 0.2 | 31.4 ± 0.4 | 34.2 ± 1.2 | 36.2 ± 0.2 | − | − | − | − | − | |
| Positive wells | 3/3 | 5/5 | 3/3 | 5/5 | 2/4 | ||||||
| P. knowlesi | 25.6 ± 0.1 | 27.6 ± 0.1 | 30.3 ± 0.1 | 33.6 ± 0.5 | 34.5 ± 1.0 | 35.0 ± NA | 35.5 ± 0.1 | − | − | − | |
| Positive wells | 3/3 | 3/3 | 2/2 | 2/2 | 5/5 | 1/5 | 3/5 | ||||
Results are presented in mean Ct (cycle threshold) ± standard deviation according to the level of parasitemia (p/µl, parasite/µl). In bold and italics, the LoD chosen. NA non-applicable. *Number of positive well in each real time triplicate.