Volume 11, Number 8—August 2005
Research
Sheep Feed and Scrapie, France
Sandrine Philippe*, Christian Ducrot†, Pascal Roy‡, Laurent Remontet‡, Nathalie Jarrige*, and Didier Calavas*
Table 1
Univariate analysis of potential risk factors
| Risk factors | Modalities | No. controls (%) | No. cases (%) | Univariate Clog-log model |
|
|---|---|---|---|---|---|
| OR* | 80% CI | ||||
| Direct contacts between flocks and indirect environmental contacts | |||||
| Purchase of ewes | No | 227 (65) | 55 (59) | 1.0 | – |
| Yes | 123 (35) | 39 (41) | 1.3 | 1.0–1.8 | |
| Purchase of rams | No | 146 (42) | 33 (35) | 1.0 | – |
| Yes | 204 (58) | 61 (65) | 1.0 | 0.8–1.4 | |
| Temporary direct contacts between flocks† | No | 230 (66) | 66 (70) | 1.0 | – |
| Yes | 120 (34) | 28 (30) | 0.7 | 0.5–1.1 | |
| Stay of animals in other flocks with direct contacts | No | 319 (91) | 87 (93) | 1.0 | – |
| Yes | 31 (9) | 7 (7) | 0.7 | 0.4–1.3 | |
| Stay of animals from other flocks with direct contacts | No | 332 (95) | 91 (97) | 1.0 | – |
| Yes | 18 (5) | 3 (3) | 0.8 | 0.4–1.9 | |
| Presence of small ruminants in the vicinity of the farm | No | 71 (20) | 14 (15) | 1.0 | – |
| Yes | 279 (80) | 80 (85) | 1.1 | 0.7–1.7 | |
| Sharing paths | No | 149 (43) | 39 (41) | 1.0 | – |
| Yes | 201 (57) | 55 (59) | 0.9 | 0.7–1.2 | |
| Other indirect environmental contacts‡ | No | 311 (89) | 85 (90) | 1.0 | – |
| Yes | 39 (11) | 9 (10) | 0.7 | 0.4–1.2 | |
| Feeding | |||||
| Purchase of raw materials§ | No | 213 (61) | 66 (70) | 1.0 | – |
| Yes | 137 (39) | 28 (30) | 0.6 | 0.4– 0.8 | |
| Purchase of milk replacers¶ | No | 287 (82) | 66 (70) | 1.0 | – |
| Yes | 63 (18) | 28 (30) | 2.0 | 1.4–2.7 | |
| Purchase of proprietary concentrates¶ | No | 79 (23) | 7 (7) | 1.0 | – |
| Yes | 271 (77) | 87 (93) | 2.2 | 1.2–3.8 | |
| Purchase of milk replacers from factory 1 | No | 329 (94) | 76 (81) | 1.0 | – |
| Yes | 21 (6) | 18 (19) | 3.1 | 2.1–4.6 | |
| Purchase of milk replacers from other factories | No | 317 (91) | 87 (93) | 1.0 | – |
| Yes | 33 (9) | 7 (7) | 0.9 | 0.5–1.6 | |
| Purchase of proprietary concentrates from factory 1 | No | 271 (77) | 48 (51) | 1.0 | – |
| Yes | 79 (23) | 46 (49) | 2.6 | 1.9–3.5 | |
| Purchase of proprietary concentrates from factory 2 | No | 292 (83) | 85 (90) | 1.0 | – |
| Yes | 58 (17) | 9 (10) | 0.4 | 0.2–0.7 | |
| Purchase of proprietary concentrates from other factories | No | 228 (65) | 54 (57) | 1.0 | – |
| Yes | 122 (35) | 40 (43) | 1.2 | 0.8–1.7 | |
| Other indirect contacts | |||||
| Artificial insemination | No | 247 (71) | 57 (61) | 1.0 | – |
| Yes | 103 (29) | 37 (39) | 1.0 | 0.7–1.5 | |
| Cesarean section performed by veterinarian | No | 163 (47) | 28 (30) | 1.0 | – |
| Yes | 187 (53) | 66 (70) | 1.9 | 1.3–2.7 | |
| Ear-tagging | No | 236 (67) | 55 (59) | 1.0 | – |
| Yes | 114 (33) | 39 (41) | 1.1 | 0.8–1.6 | |
| Sharing of farming devices | No | 85 (24) | 22 (23) | 1.0 | – |
| Yes | 265 (76) | 72 (77) | 0.7 | 0.5–1.0 | |
| Presence of dogs on the farm | No | 325 (93) | 84 (89) | 1.0 | – |
| Yes | 25 (7) | 10 (11) | 1.1 | 0.7–1.7 | |
| Purchase of hay | No | 247 (71) | 70 (74) | 1.0 | – |
| Yes | 103 (29) | 24 (26) | 0.7 | 0.5–1.0 | |
*OR, odds ratio; CI, confidence interval.
†Contacts by transhumance or common pastures with contacts between animals.
‡e.g., common pastures without direct contacts between animals.
§Purchase of hay excluded because considered in other indirect contacts.
¶Independently of the factories.
