Table 1. Parasitological findings at three cross-sectional surveys following a 6 months intervention period with different IPT regimes.
| Characteristics | Placebo | SP bimonthly | AS+AQ bimonthly | AS+AQ monthly | ||||
| All | Asympta | All | Asympta | All | Asympta | All | Asympta | |
| After the intervention period (n) | 591 | 579 | 555 | 541 | 502 | 476 | 579 | 573 |
| Any parasiteamiab (%) | 19.8 | 19.0 | 17.5 | 16.1 | 20.5 | 18.3 | 5.2* | 4.9* |
| Parasitaemiab>7000/µl (%) | 6.9 | 6.7 | 7.9 | 6.8 | 8.2 | 6.3 | 1.6* | 1.6* |
| Parasite density(geometric mean, (range)) | 2516(40–68440) | 2465(40–68440) | 4754(80–180800) | 4014(80–92800) | 3290(80–213240) | 2517(80–213240) | 1889(80–115320) | 2010(80–115320) |
| msp2 diversity (median, (range)) | 2 (1–8) | 2 (1–8) | 2 (1–5) | 2 (1–5) | 2 (1–6) | 2 (1–6) | 2 (1–2) | 2 (1–2) |
| >1 msp2 clone (%) | 70.6 | 70.1 | 67.4 | 70.1 | 60.5 | 60.6 | 66.7 | 69.2 |
| ≥3 msp2 clones (%) | 36.3 | 36.1 | 32.6 | 32.5 | 29.8 | 28.2 | 0 | 0 |
| Post intervention dry season (n) | 481 | 476 | 442 | 436 | 403 | 400 | 463 | 456 |
| Any parasitaemiab (%) | 6.7 | 6.1 | 10.6* | 9.9* | 10.0 | 9.5 | 11.2* | 10.3* |
| Parasitaemiab>7000/µl (%) | 2.1 | 1.5 | 4.5* | 4.1* | 2.5 | 2.5 | 3.2 | 2.6 |
| Parasite density(geometric mean, (range)) | 2112(120–121600) | 1619(120–89600) | 4529(240–162240) | 4719(240–162240) | 1776(120–140000) | 1825(120–140000) | 2926(80–168800) | 2615(80–168800) |
| msp2 diversity (median, (range)) | 2 (1–6) | 2 (1–6) | 2 (1–4) | 2 (1–4) | 2 (1–6) | 2 (1–6) | 2 (1–5) | 2 (1–5) |
| >1 msp2 clone (%) | 50.0 | 50.0 | 55.0 | 54.1 | 69.0 | 67.9 | 54.3 | 53.7 |
| ≥3 msp2 clones (%) | 29.2 | 31.8 | 25.0 | 24.3 | 24.3 | 25.0 | 23.9 | 22.0 |
| Post intervention rainy season (n) | 448 | 434 | 401 | 392 | 363 | 357 | 430 | 419 |
| Any parasitaemiab (%) | 37.3 | 35.5 | 36.4 | 35.5 | 38.0 | 37.3 | 41.2 | 39.9 |
| Parasitaemiab >7000/µl (%) | 8.9 | 8.3 | 7.5 | 6.9 | 8.8 | 8.1 | 10.2 | 8.8 |
| Parasite density(geometric mean, (range)) | 2249(40–172480) | 2231(40–172480) | 2187(40–162240) | 2003(40–162240) | 2399(40–169240) | 2214(40–141360) | 2223(40–332960) | 1995(40–332960) |
| msp2 diversity (median, (range)) | 2 (1–8) | 2 (1–7) | 2 (1–6) | 2 (1–6) | 2 (1–6) | 2 (1–6) | 2 (1–7) | 2 (1–7) |
| >1 msp2 clone (%) | 74.8 | 75.2 | 72.9 | 72.3 | 74.5 | 74.7 | 71.7 | 70.6 |
| ≥3 msp2 clones (%) | 43.7 | 44.0 | 44.9 | 44.6 | 44.1 | 43.4 | 44.1 | 43.7 |
These parasitological data have been presented previously [10]. The prevalence figures presented here differ slightly from those in the previous publication because it was not possible to obtain data on parasite genotype for all the children in the study due to missing samples.
a
Excluding children with clinical malaria at survey, 28 days before and 7 days after.
b
Determined by microscopy.
*
compared to the placebo group p<0.05 (Chi-square).