Characteristics of a group of individuals exposed to Giardia infection during an outbreak 3 years earlier and a control group who did not contract the infection
| Characteristics | Exposed (n=817) | Controls (n=1128) | p Value |
| Female gender, n (%) | 540 (66.1) | 738 (65.4) | 0.759* |
| Age | |||
| Mean, years (range) | 36.0 (4–94) | 36.3 (4–89) | 0.667† |
| Age 0–19, n (%) | 39 (4.8) | 36 (3.2) | 0.108* |
| Age 20–39, n (%) | 526 (64.4) | 736 (65.2) | |
| Age 40–59, n (%) | 187 (22.9) | 276 (24.5) | |
| Age 60–79, n (%) | 56 (6.9) | 76 (6.7) | |
| Age 80–99, n (%) | 9 (1.1) | 4 (0.4) | |
| Marital status | |||
| Single, n (%) | 271 (33.5) | 293 (26.1) | 0.004* |
| Married, n (%) | 497 (61.4) | 778 (69.3) | |
| Divorced, n (%) | 33 (4.1) | 41 (3.7) | |
| Widowed, n (%) | 9 (1.1) | 11 (1.0) | |
| Education, highest level | |||
| Primary school, n (%) | 37 (4.7) | 59 (5.3) | 0.004* |
| Secondary school, n (%) | 169 (21.3) | 308 (27.7) | |
| University, n (%) | 587 (74.0) | 746 (67.0) | |
| Main occupation | |||
| Worker, n (%) | 576 (71.1) | 881 (78.7) | <0.001* |
| Student, n (%) | 137 (16.9) | 121 (10.8) | |
| Unemployed/retired, n (%) | 70 (8.6) | 96 (8.6) | |
| Other, n (%) | 27 (3.3) | 22 (2.0) | |
| Student during the outbreak | |||
| Yes, n (%) | 299 (37.3) | 269 (24.2) | <0.001* |
| No, n (%) | 503 (62.7) | 842 (75.8) | |