Table 2. Risk factors associated with EV71 seropositivity in preschool children in 2017.
| Factor |
Seropositive (N = 34) |
Seronegative (N = 440) |
OR, 95% CI | p value | |
|---|---|---|---|---|---|
| Sex | Male | 13 (38.2%) | 245 (55.7%) | Ref. | |
| Female | 21 (61.8%) | 195 (44.3%) | 2.03, (1.00, 4.26) | 0.05 | |
| Age (years) | Mean±SD | 2.8±1.8 | 2.5±1.6 | 0.45 | |
| Residential area | City | 23 (67.6%) | 287 (65.2%) | Ref. | |
| Village | 9 (26.5%) | 113 (25.7%) | 0.45, (0.45, 2.21) | 0.99 | |
| Suburban | 2 (5.9%) | 35 (8.0%) | 0.71, (0.16, 3.15) | 0.66 | |
| Industrial | 0 (0%) | 5 (1.1%) | NA | ||
| Household size | Mean±SD | 4.1±1.7 | 4.3±1.8 | 0.53 | |
| Sibling | No | 6 (17.7%) | 167 (38.0%) | Ref. | |
| Yes | 28 (82.3%) | 273 (62.0%) | 2.85, (1.16, 7.04) | 0.02 | |
| Mean±SD | 1.2±1.0 | 0.8±0.8 | 0.005 | ||
| History of chronic illness | No | 29 (85.3%) | 404 (91.8%) | Ref. | |
| Yes | 5 (14.7%) | 36 (8.2%) | 1.93, (0.71, 5.30) | 0.19 | |
| Ever breastfed | No | 1 (2.9%) | 31 (7.1%) | Ref. | |
| Yes | 33 (97.1%) | 409 (92.9%) | 2.50, (0.33, 18.89) | 0.36 | |
| Attendance of kindergartens or daycare center | No | 9 (26.5%) | 163 (37.1%) | Ref. | |
| Yes | 25 (73.5%) | 277 (62.9%) | 1.64, (0.75, 3.59) | 0.22 | |
| Main source of drinking water | Tap water | 19 (55.9%) | 260 (59.1%) | Ref. | |
| Well water | 0 (0%) | 2 (0.5%) | NA | ||
| Spring | 4 (11.8%) | 51 (11.5%) | 1.07, (0.35, 3.29) | 0.90 | |
| Others | 11 (32.3%) | 127 (28.9%) | 1.19, (0.55, 2.57) | 0.67 | |
| History of HFMD | No | 22 (64.7%) | 334 (75.9%) | Ref. | |
| Yes | 11 (32.4%) | 99 (22.5%) | 1.69, (0.79, 3.60) | 0.18 | |
| Unknown | 1 (2.9%) | 7 (1.6%) | |||
| History of herpangina | No | 26 (76.5%) | 316 (71.8%) | Ref. | |
| Yes | 8 (23.5%) | 110 (25.0%) | 0.88, (0.39, 2.01) | 0.77 | |
| Unknown | 0 (0.0%) | 14 (3.2%) | |||
| Family member with history of HFMD and/or herpangina | No | 20 (58.8%) | 288 (65.5%) | Ref. | |
| Yes | 13 (38.2%) | 134 (30.4%) | 1.40, (0.68, 2.89) | 0.37 | |
| Unknown | 1 (2.9%) | 18 (4.1%) | |||
| Classmates with history of HFMD and/or herpangina | No | 1 (2.9%) | 38 (8.6%) | Ref. | |
| Yes | 19 (55.9%) | 134 (30.5%) | 5.39, (0.70, 41.56) | 0.11 | |
| Unknown | 14 (41.2%) | 268 (60.9%) | |||
| Contact with history of HFMD or herpangina | No | 7 (20.6%) | 173 (39.3%) | Ref. | |
| Yes | 18 (52.9%) | 144 (32.7%) | 3.09, (1.26, 7.60) | 0.01 | |
| Unknown | 9 (26.5%) | 123 (28.0%) |
The p values were measured by Student’s t-test or chi-squared test. SD denotes standard deviation; HFMD, hand, foot and mouth disease; OR, odds ratio; CI, confidence interval; NA, not available.