Table 3. Parasite clearance determined by microscopy in Plasmodium falciparum–positive persons, Zanzibar*.
| Characteristic | Study group |
||||
|---|---|---|---|---|---|
| 2002–2003, n = 206 | 2005, n = 172 | 2017, all patients, n = 142 | 2017, age <5 y, n = 21 | 2017, parasite density >2,000/μL, n = 115 | |
| Parasite positivity by microscopy, no.; % (95% CI) | |||||
| Day 0 | 206; 100 (98–100) | 172; 100 (98–100) | 142; 100 (97–100) | 21; 100 (84–100) | 115; 100 (97–100) |
| Day 1 | 137; 67 (60–73) | 64; 37 (30–45) | 58; 41 (33–49) | 12; 41 (34–78) | 53; 46 (37–56) |
| Day 2 | 18; 9 (5–13) | 1; 0.6 (0–3) | 2; 1 (0–5) | 0; 0 (0–16) | 1; 1 (0–5) |
| Day 3 |
1; 0.5 (0–3) |
0; 0 (0–2) |
1; 0.7 (0–4) |
0; 0 (0–16) |
0; 0 (0–3) |
| Geometric mean parasite density/µL for parasite-positive persons (range) | |||||
| Day 0 | 19,858 (2,000–198,447) | 20,822 (2,000–176,000) | 7,899 (75–304,000) | 15,773 (85–304,000) | 14,305 (2,175–304,000) |
| Day 1 | 359 (9–173,882) | 397 (12–25,000) | 822 (30–13,700) | 802 (64–4,970) | 83 (30–13,700) |
| Day 2 | 89 (32–552) | 560, NA | 500 (250–1,000) | NA, NA | 1,000, NA |
| Day 3 | 78, NA | NA, NA | 120, NA | NA, NA | NA, NA |
*Values are proportions of patients positive by microscopy and with geometric mean parasite densities on days 0, 1, 2, and 3 after treatment. NA, not applicable.