Table 3.
Odds ratios for selected characteristics of first-grade case-patients, as compared with controls
| Characteristic | Case-patients | Controls | Unadjusted OR (95% CI) | P | AORa (95% CI) | P |
|---|---|---|---|---|---|---|
| No./total (%) | No./total (%) | |||||
| Male | 15/23 (65) | 29/75 (39) | 2.97 (1.02–9.09) | 0.05 | 3.11 (0.64–15.07) | 0.16 |
| Hispanic | 9/23 (39) | 11/75 (15) | 3.74 (1.12–12.06) | 0.02 | 15.60 (1.68–144.60) | 0.02 |
| Previous Escherichia coli infection | 2/23 (9) | 3/75 (4) | 2.29 (0.18–21.15) | 0.33 | ||
| Live on a farm | 0/23 (0) | 5/75 (7) | 0.47 (0–3.58) | 0.51 | ||
| Previous farm animal exposure | 7/23 (30) | 33/75 (44) | 0.56 (0.17–1.65) | 0.33 | ||
| Antibiotic use, previous month | 1/22 (5) | 4/70 (6) | 0.79 (0.02–8.55) | 1.00 | ||
| Knowledge, awareness, general habits | ||||||
| Bites nails always | 6/23 (26) | 4/75 (5) | 6.26 (1.29–32.90) | 0.01 | 4.84 (0.39–59.73) | 0.22 |
| Sucks thumb/fingers | 5/23 (22) | 10/75 (13) | 1.81 (0.43–6.70) | 0.33 | ||
| Aware disease transmission, animal contact | 12/22 (55) | 52/71 (73) | 0.44 (0.15–1.35) | 0.12 | ||
| Aware disease transmission, surfaces | 12/22 (55) | 55/72 (76) | 0.37 (0.12–1.15) | 0.06 | ||
| Always washes hands before eating | 10/23 (43) | 23/73 (32) | 1.67 (0.56–4.83) | 0.32 | ||
| Instructed to wash hands after animal contact | 9/20 (45) | 44/64 (69) | 0.37 (0.12–1.18) | 0.07 | ||
| Instructed not to eat or drink in animal areas | 6/18 (33) | 29/61 (48) | 0.55 (0.15–1.86) | 0.42 | ||
| Event exposures | ||||||
| Visited petting zoo | 23/23 (100) | 71/74 (96) | Undefined | 1.00 | ||
| Hand sanitiser after petting zoo | 18/23 (78) | 66/70 (94) | 0.22 (0.04–1.15) | 0.04 | 0.35 (0.05–2.27) | 0.27 |
| Hand sanitiser before petting zoo | 21/23 (91) | 58/69 (84) | 1.99 (0.38–19.83) | 0.51 | ||
| Touched animal at petting zoo | 22/23 (96) | 69/71 (97) | 0.64 (0.03–39.31) | 1.00 | ||
| Touched hay bales | 19/23 (83) | 40/69 (58) | 3.44 (0.98–15.21) | 0.04 | 1.85 (0.14–25.52) | 0.64 |
| Played in sawdust pile | 1/21 (5) | 6/62 (10) | 0.47 (0.01–4.26) | 0.67 | ||
| Contact with cows at event | 18/19 (95) | 55/65 (85) | 3.27 (0.41–149.78) | 0.44 | ||
| Day of attendance | ||||||
| Tuesday, April 21 | 14/23 (61) | 24/75 (32) | 3.38 (1.07–10.74) | 0.05 | 6.66 (0.94–47.39) | 0.07 |
| Wednesday, April 22 | 4/23 (17) | 22/75 (29) | 1.05 (0.25–4.39) | 0.47 (0.03–6.62) | ||
| Thursday, April 23 | 5/23 (22) | 29/75 (39) | 1.00 | 1.00 | ||
| Morning attendance | 14/23 (61) | 53/75 (71) | 0.65 (0.22–1.96) | 0.44 | ||
| Food and beverages | ||||||
| Ate in barn | 0/23 (0) | 6/68 (9) | Undefined | 0.33 | ||
| Lunch at fairgrounds | 8/23 (35) | 28/75 (37) | 0.90 (0.29–2.60) | 1.00 | ||
| Lunch at fairgrounds, after event | 5/23 (22) | 19/75 (25) | 0.82 (0.21–2.73) | 1.00 | ||
| Drank beverage in barn | 17/23 (74) | 50/74 (68) | 1.36 (0.44–4.75) | 0.62 | ||
| Drank chocolate milk | 19/23 (83) | 66/73 (90) | 0.50 (0.11–2.62) | 0.45 | ||
| Handwashing before lunchb | 5/18 (18) | 35/55 (64) | 0.22 (0.05–0.79) | 0.01 | 0.13 (0.02–0.88) | 0.04 |
| Handwashing before lunch, after eventb | 4/14 (29) | 27/42 (64) | 0.22 (0.04–0.96) | 0.03 |
a
Adjusted model includes gender, ethnicity, nail biting, hand sanitiser use after petting zoo, touching hay bales, day of attendance and handwashing before lunch.
b
Handwashing with soap and water or hand sanitiser.
No, number; OR, odds ratio; CI, confidence interval; P, P value; AOR, adjusted odds ratio.