| Follow up time | ||
|
| 6 months (n = 427) | 12 months (n = 406) |
| n (%) | n (%) | |
| Age (years) |
|
|
| ≤9 | 320 (74.94) | 180 (44.33) |
| ≥10 | 107 (25.06) | 226 (55.67) |
| Gender |
|
|
| Female | 225 (52.7) | 213 (52.5) |
| Male | 202 (47.3) | 193 (47.5) |
| Type of water source |
|
|
| Lake or pond water | 314 (73.5) | 293 (72.2) |
| Tap water | 113 (26.5) | 113 (27.8) |
| Contact with lake in the past 1 week |
|
|
| Yes | 383 (89.7) | 361 (88.9) |
| No | 44 (10.3) | 45 (11.1) |