Table 2.
Exposure to risk factors, outbreak cases due to Cryptosporidium infection in schoolchildren visiting a holiday farm in Norway, 5–23 March 2012 (n = 145)
| Contact with animals | Exposed | Not exposed | RR* (95% CI) | P value | ||||
|---|---|---|---|---|---|---|---|---|
| Ill | Total | Ill | Total | |||||
| Goat/kids | 40 | 145 | 28% | 0 | 0 | – | – | – |
| Lambs | 13 | 27 | 48% | 27 | 118 | 23% | 2·1 (1·3–3·5) | 0·01 |
| Drinking milk directly from goat | 25 | 72 | 35% | 14 | 69 | 20% | 1·7 (1·0–3·0) | 0·05 |
| Attending >50% of animal contact sessions† | 18 | 34 | 53% | 22 | 111 | 20% | 2·67 (1·6–4·4) | <0·01 |
RR, Risk ratio; CI, confidence interval.
*
Risk ratios are crude.
†
Contact sessions with the animals includes petting and playing with the animals and routine farm work.