Table 2.
In vitro sensitivity of Plasmodium falciparum isolates collected during 2006–2007 and 2008–2009 to chloroquine (CQ), quinine (QN), mefloquine (MQ), and artesunate (AS) and their sensitivity classification
| Drug | Sensitivity classification |
Year 2006–2007 |
Year 2008–2009 |
||
|---|---|---|---|---|---|
| % (n) | IC 50 , nM | % (n) | IC 50 , nM | ||
| AS |
All |
100 (56) |
2.0 (1.5–2.4) |
100 (63) |
2.0 (1.5–2.5) |
| Sensitive |
60.7 (34) |
1.4 (1.3–1.6) |
58.7 (37) |
1.4 (1.1–1.8) |
|
| Declined sensitivity |
39.3 (22) |
3.1 (2.8–3.3) |
41.3 (26) |
3.7 (3.2–4.2) |
|
| MQ |
All |
100 (56) |
30.4 (18.0–42.7) |
100 (63) |
28.8 (16.7–41.0) |
| Sensitive |
42.9 (24) |
13.8 (11.3–16.3) |
41.3 (26) |
16.2 (13.2–19.2) |
|
| Resistant |
57.1 (32) |
51.5 (40.3–62.7) |
58.3 (37) |
58.7 (49.3–68.1) |
|
| CQ |
All |
100 (56) |
69.9 (62.8–77.1) |
100 (63) |
72.3 (65.4–79.2) |
| Sensitive |
1.8 (1) |
9.6 |
– |
– |
|
| Moderate resistant |
76.8 (43) |
65.9 (59.9–72.0) |
69.8 (44) |
66.6 (62.3–70.8) |
|
| Highly resistant |
21.4 (12) |
124.3 (108.1–140.6) |
30.2 (19) |
132.3 (68.1–196.5) |
|
| QN | All |
100 (56) |
236.3 (186.2–286.4) |
100 (63) |
230.5 (164.8–296.2) |
| Sensitive |
78.6 (44) |
223.0 (178.6–267.3) |
93.7 (59) |
214.9 (150.4–279.4) |
|
| Resistant | 21.4 (12) | 648.9 (606.1–691.6) | 6.3 (4)** | 593.6 (491.0–696.2) | |
Data presented as median IC50 (95% CI) and percentage (number).
**Significant lower proportion than isolates collected from 2006–2007 (p = 0.016, Chi–square test).