Table 1. Characteristics of BU cases and controls.
| Variables | Cases [N (%)] | Controls [N (%)] | p value |
| Age | 0.77 | ||
| <15 years | 62 (59.6) | 191 (61.2) | |
| ≥15 years | 42 (40.4) | 121 (38.8) | |
| Gender | |||
| Male | 61 (58.7) | 183 (58.7) | |
| Female | 43 (41.3) | 129 (41.3) | |
| Geographical origin | |||
| Ze | 75 (72.1) | 225 (72.1) | |
| Allada | 10 (9.6) | 30 (9.6) | |
| Toffo | 9 (8.7) | 27 (8.7) | |
| So Ava | 6 (5.8) | 18 (5.8) | |
| Abomey Calavi | 3 (2.9) | 9 (2.9) | |
| Tori bossito | 1 (1.0) | 3 (1.0) | |
| Marital status | 0.38 | ||
| Single | 77 (74.0) | 244 (78.2) | |
| Other | 27 (26.0) | 68 (21.8) | |
| Hereditary disease in the family | 0.43 | ||
| Yes | 16 (15.4) | 39 (12.5) | |
| No | 88 (84.6) | 273 (87.5) | |
| Daily contact with natural water | 0.08 | ||
| Yes | 76 (73.1) | 199 (63.8) | |
| No | 28 (26.9) | 113 (36.2) |
(Total cases/Total controls = 104/312).