Table 1.
Prevalence of S. aureus and MRSA in bulk tank milk of the 11 provinces and associated confidence intervals
| S. aureus | MRSA | |||||
|---|---|---|---|---|---|---|
| Province | Median herd size | Sampled farms | Positive samples | % (95% CI)* | Positive samples | % (95% CI)† |
| Bergamo | 73 | 91 | 53 | 58·2 (48·1–68·4) | 3 | 3·3 (0·7–9·1) |
| Brescia | 149 | 97 | 53 | 54·6 (44·2–64·7) | 1 | 1·0 (0–5·6) |
| Como | 57 | 65 | 19 | 29·2 (18·9–42·0) | 0 | 0 (0–5·5) |
| Cremona | 328 | 91 | 42 | 46·2 (39·4–55·8) | 10 | 10·8 (5·3–10·9) |
| Lecco | 51 | 30 | 13 | 43·3 (26·0–62·3) | 0 | 0 (0–11·6) |
| Lodi | 282 | 78 | 35 | 44·9 (33·7–56·5) | 5 | 6·4 (2·1–14·3) |
| Mantova | 167 | 92 | 43 | 35·8 (26·7–45·0) | 2 | 5·7 (2·1–11·9) |
| Milano | 155 | 106 | 38 | 46·7 (35·5–56·3) | 6 | 2·1 (0·3–7·5) |
| Pavia | 173 | 54 | 18 | 33·3 (21·5–47·6) | 2 | 3·7 (0·5–12·8) |
| Sondrio | 20 | 92 | 63 | 68·5 (57·8–77·5) | 2 | 2·2 (0·3–7·6) |
| Varese | 93 | 48 | 21 | 43·8 (29·8–58·7) | 1 | 2·1 (0–11·1) |
| Total | 127 | 844 | 398 | 47·2 (43·8–50·5) | 32 | 3·8 (2·5–5·1) |
*
Confidence intervals based on the Normal distribution approximation.
†
Exact confidence intervals based on Clopper–Pearson's method.