| Source of Water | Relative Risks | Attack Rates (%) |
| Boiled | 0 | 0.0 |
| Filtered | 0.4 | 18.8 |
| Stream | 0.5 | 22.2 |
| Tank | 0.5 | 26.6 |
| Pipe-Borne | 1 | 37.1 |
| Sachet | 1.2 | 38.7 |
| Well | 2.7 | 60 |