Table 3.
Annual clinical and parasite responses to dihydroartemisinin-piperaquine treatment of uncomplicated Plasmodium falciparum malaria in Ninh Thuan province, Vietnam
| Characteristic | 2013 (n = 77) | 2014 (n = 56) | 2015 (n = 55) | P value* |
|---|---|---|---|---|
| Parasite clearance time (PCT100) | ||||
| Median (IQR) [hours] | 36 (24.42) | 30 (24.36) | 30 (24.36) | 0.29 |
| Proportion with PCT > 72 h | 5% (4/77) | 7% (4/56) | 2% (1/55) | |
| Parasite clearance half- life T1/2 [hours] | ||||
| Median (IQR) | 1.73 (1.38; 2.05) | 1.78 (1.44; 2.36) | 2.16 (1.75; 2.73) | 0.29 |
| Geometric mean (95% CI) | 1.84 (1.66; 2.03) | 1.98 (1.73; 2.27) | 2.19 (2.01; 2.39) | |
| T1/2 > 5 h | 5/76 (7%) | 5/56 (9%) | 1/54 (2%) | |
| Fever clearance time [hours] | ||||
| Median (IQR) [hours] | 30 (24.54) | 18 (12.30) | 18 (12.24) | <0.001 |
| Treatment outcome (WHO) | ||||
| APCR# | 62/77 (81%) | 45/56 (80%) | 43/55 (78%) | – |
| Early treatment failure | 0/77 (0%) | 0/56 (0%) | 0/55 (0%) | |
| Clinical treatment failure | 3/77 (4%) | 1/56 (2%) | 0/55 (0%) | |
| Parasite treatment failure | 5/77 (6%) | 1/56 (2%) | 2/55 (4%) | |
| Withdrawal | 2/77 (3%) | 0/56 (0%) | 0/55 (0%) | |
| Loss to follow-up | 5/77 (6%) | 9/56 (16%) | 10/55 (18%) | |
| Risk of failure [PCR-uncorrected] | ||||
| Uncorrected Kaplan–Meier estimate (ITT) | 11% | 4% | 4% | 0.046 |
| Uncorrected proportion (per protocol) | 8/70 (11%) | 2/47 (4%) | 2/45 (4%) | 0.05 |
| Risk of failure [PCR-corrected] | ||||
| Corrected Kaplan–Meier estimate (ITT) | 0% | 4% | 0% | 0.81 |
| Corrected proportion (per protocol) | 0/62 (0%) | 2/47 (4%) | 0/43 (0%) | 0.80 |
| K13-propeller mutation | I543T: 1/77 (1%) Y493H: 4/77 (5%) Total 5/77 (6%) |
C580Y: 2/56 (3.5%) Y493H:2/56 (3.5%) 4/56 (7%) |
C580Y: 2/55 (4%) | 0.53 |
* P values are based on linear trend tests
APCR adequate clinical and parasitological responses