TABLE 1.
In vitro susceptibilities of Plasmodium falciparum strains from the China-Myanmar border area to piperaquinea
| Period (yr) | No. | Median (IQR) |
No. (%) |
Median AUC (IQR)d | |||
|---|---|---|---|---|---|---|---|
| IC50 (nM) | IC90 (nM) | PSA (%) | PSA ≥ 10%b | Bimodalc | |||
| 2007 | 17 | 4.8 (2.9–6.2) | 8.6 (6.0–11.2) | 1.9 (1.2–6.2) | 0 | 6 (35.3) | 0.0 (0–11.6) |
| 2008 | 19 | 5.9 (3.7–7.5) | 8.0 (6.1–12.6) | 2.8 (1.4–3.9) | 0 | 10 (52.6) | 1.7 (0–15.8) |
| 2009 | 14 | 5.4 (4.4–6.2) | 11.5 (7.0–15.1) | 2.4 (1.9–5.8) | 2 (14.3) | 9 (64.3) | 7.2 (0–15.9) |
| 2010–2012 | 7 | 6.2 (4.8–8.0) | 13.1 (7.0–15.5) | 4.0 (1.8–9.2) | 1 (14.3) | 3 (42.9) | 0.0 (0–6.9) |
| 2013 | 36 | 5.4 (3.9–7.0) | 10.2 (7.1–11.6) | 3.7 (2.3–5.7) | 2 (5.6) | 19 (52.8) | 5.5 (0–19.5) |
| 2014–2016 | 27 | 6.8 (5.1–7.8) | 11.0 (9.2–13.8) | 5.2 (3.8–7.5) | 2 (7.4) | 21 (77.8) | 11.2 (1.5–18.8) |
| Totale | 120 | 5.6 (4.1–7.1)* | 10.1 (7.1–12.6)** | 3.8 (2.0–6.1)† | 7 (5.8) | 68 (56.7) | 5.6 (0–16.5)‡ |
a
AUC, area under the curve; IQR, interquartile range; PSA, piperaquine survival assay score.
b
Number and percentage of parasites with a PSA of ≥10%.
c
Number and percentage of parasites with bimodal PPQ response curves (67.4%).
d
AUC for the drug response curve at PPQ concentrations of 102 to 105 nM.
e
A Kruskal-Wallis test was used to compare results between years (*, P = 0.0557; **, P = 0.1103; †, P = 0.0450; ‡, P = 0.1246). A Mann-Kendall trend test was used to evaluate the presence of annual trends for IC50, IC90, PSA, and AUC values (all of which were nonsignificant).