Table 1.
Descriptive Results for Baseline and Final Survey per Study Arm (All Study Age Groups)
| Children Aged 9–12 Years | Children Aged 5–8 Years | Adults Aged 20–55 Years | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Variables | Arm 1 | Arm 2 | Arm 3 | Arm 4 | Arm 1 | Arm 2 | Arm 3 | Arm 4 | Arm 1 | Arm 2 | Arm 3 | Arm 4 |
| Number of villages | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 16 |
| Number of people tested at baseline | 1544 | 1573 | 1506 | 1469 | 820 | 788 | 804 | 726 | 727 | 761 | 762 | 759 |
| Proportion female N (%) at baseline | 627 (40.6) | 708 (45.0) | 672 (44.6) | 662 (45.0) | 427 (52.1) | 383 (48.6) | 378 (47.0) | 342 (47.1) | 434 (59.7) | 473 (62.1) | 461 (60.5) | 443 (58.4) |
| Number of people infected at baseline | 383 | 159 | 210 | 233 | 147 | 50 | 87 | 48 | 85 | 46 | 70 | 85 |
| Prevalence at baseline (%) | 24.8 | 10.1 | 13.9 | 15.9 | 17.9 | 6.4 | 10.8 | 6.6 | 11.7 | 6.0 | 9.2 | 11.0 |
| Number of villages | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 16 | 16 |
| Number of people tested in final survey | 1473 | 1441 | 1419 | 1356 | 812 | 771 | 755 | 789 | 646 | 611 | 598 | 593 |
| Proportion female N (%) in final survey | 735 (49.9) | 693 (48.1) | 728 (51.3) | 677 (49.9) | 414 (51.0) | 382 (49.5) | 385 (51.0) | 385 (48.8) | 352 (54.5) | 356 (58.3) | 337 (56.3) | 312 (52.6) |
| Number of people infected in final survey | 111 | 50 | 8 | 46 | 66 | 27 | 19 | 22 | 11 | 14 | 11 | 3 |
| Prevalence at final survey (%) | 7.5 | 3.5 | 0.6 | 3.4 | 8.1 | 3.5 | 2.5 | 2.8 | 1.7 | 2.3 | 1.8 | 0.5 |
| Absolute difference between prevalence at final survey and baseline | −17.3 | −6.6 | −13.4 | −12.5 | −9.8 | −2.9 | −8.3 | −3.8 | −10.0 | −3.8 | −7.3 | −10.7 |
| Relative difference in prevalence between final survey and baseline (% change) | −69.6 | −65.7 | −96.0 | −78.6 | −54.7 | −44.9 | −76.7 | −57.8 | −85.5 | −62.1 | −80.0 | −95.5 |
| Village-level arithmetic mean infection intensity at baseline (including zeros) | 17.9 | 5.7 | 8.4 | 6.2 | 9.6 | 4.1 | 4.5 | 2.0 | 11.7 | 6.0 | 9.2 | 11.0 |
| Village-level arithmetic mean infection intensity at final survey (including zeros) | 11.7 | 1.6 | 0.3 | 0.7 | 8.2 | 3.2 | 0.5 | 0.6 | 0.4 | 0.3 | 0.3 | 0.1 |
| Egg reduction rate (%) | 34.6 | 71.9 | 96.4 | 88.7 | 14.6 | 22.0 | 88.9 | 70.0 | 96.6 | 95.0 | 96.7 | 99.1 |
Arm 1: Praziquantel annual mass drug administration (MDA) before peak of transmission. Arm 2: Praziquantel annual MDA after peak of transmission. Arm 3: Praziquantel MDA biannual treatment. Arm 4: Praziquantel annual MDA before peak of transmission plus snail control. N: case number.