Volume 14, Number 9—September 2008
Research
Pigs as Source of Methicillin-Resistant Staphylococcus aureus CC398 Infections in Humans, Denmark
Hannah C. Lewis, Kåre Mølbak, Catrin Reese, Frank M. Aarestrup, Mette Selchau, Marit Sørum, and Robert L. Skov
Table 1
Statistically significant associations by univariable analysis for infection with MRSA CC398, Denmark*
| Exposure variable | No. (%) case-patients exposed (n = 21) | Odds ratio (95% confidence interval) for MRSA infection |
||
|---|---|---|---|---|
| Case–control study, population controls (n = 42) | Case–case study, non-CC398 case-patients (n = 39) | |||
| Animal and farm-related exposures | ||||
| Lived or worked on farm with animals | 14 (67) | 22.1 (2.9–170.3) | 11.6 (2.6–51.7) | |
| Worked with animals or meat | 11 (50) | 16.2 (2.0–127.8) | ∞† | |
| Worked on farm with animals | 10 (48) | ∞† | ∞† | |
| Lived on farm with animals | 9 (43) | 6.9 (1.5–32.8) | 7.9 (1.7–36.7) | |
| Exposure to pigs | 13 (62) | ∞† | ∞† | |
| Exposure to cattle | 6 (29) | ∞† | ∞† | |
| Exposure to other farm animals (hens, goats, sh eep) | 7 (33) | 11.1 (1.4–92.4) | 5.9 (1.2–28.8) | |
| Provided antimicrobial drugs to animals | 10 (48) | ∞† | ∞† | |
| Contact with farm workers | 16 (76) | 5.2 (1.4–19.3) | ∞† | |
| Contact with farmer | 14 (67) | 3.2 (1.0–10.6) | ∞† | |
| Contact with veterinarian | 7 (33) | 6.3 (1.3–30.7) | 6.6 (1.4–31.8) | |
| Lived in countryside | 13 (62) | 7.2 (1.5–33.8) | 5.2 (1.4–18.9) | |
| Had cat in home | 11 (50) | 3.2 (1.0–10.6) | 3.4 (1.1–9.9) | |
| Used manure in garden | 7 (33) | 3.2 (0.9–11.0) | 6.6 (1.4–31.8) | |
| Visited farm, zoo, or stables |
12 (57) |
0.8 (0.3–2.4) |
4.7 (1.3–17.4) |
|
| Medical-related exposures | ||||
| Admission to hospital in 12 mo before diagnosis | 13 (62) | 6.8 (1.9–24.4) | 1.5 (0.4–5.2) | |
| Someone in household with chronic condition | 12 (57) | 3.8 (1.2–12.5) | 2.0 (0.8–9.3) | |
| Antimicrobial drug use in 12 mo before diagnosis | 9 (43) | 3.4 (1.0–11.5) | 2.6 (0.8–9.2) | |
| Contact with person with skin sore or other skin infection | 5 (26) | 8.6 (1–74.9) | 0.6 (0.2–1.9) | |
*MRSA, methicillin-resistant Staphylococcus aureus; CC, clonal complex.
†p<0.01, by unmatched analysis.
