MSSA infection outcome of all orthopaedic patients during two 6-month periods
| Period A January to June 2013 No MSSA screen | Period B January to June 2014 MSSA screen (elective patients only) | |||||
|---|---|---|---|---|---|---|
| Trauma | Elective | Trauma | Elective | NK* | ||
| Total: 447 | Total: 232 | Total: 352 | Total: 307 | Total: NK | ||
| MSSA screening | No screen | No screen | No screen | MSSA Neg 218 (71%) | MSSA Pos 89 (29%) | No screen NK |
| No MSSA infection† | 435 (97.31%) | 213 (91.81%) | 343 (97.44%) | 215 (97.7%) | 85 | NK |
| Superficial MSSA infection‡ | 2 (0.45%) | 4 (1.72%) | 4 (1.14%) | 2 (0.7%) | 4 (1.3%) | 0 (0%) |
| (postoperative MSSA carriage) | (0) | (1) | (1) | (1§) | (4¶) | (0) |
| Deep MSSA infection** | 10 (2.24%) | 15 (6.47%) | 5 (1.42%) | 1†† (0.3%) | 0 (0%) | 4 NK% |
| (postoperative MSSA carriage) | (1) | (7§) | (2) | (0) | (2) | |
Among elective patients the risk ratio of any MSSA infection was 0.28 (95% CI 0.12 to 0.65) in period B compared with period A; risk ratio of any MSSA infection was 0.95 (95% CI 0.41 to 2.23) in period B compared with period A.
*Unscreened patients admitted for surgery from outpatients or another hospital.
†Excluding patients presenting at another hospital.
‡Superficial infection: skin and soft tissue only.
§Original screen negative (one patient); positive for MSSA postsurgery.
¶All four patients had superficial MSSA infection with strains resembling nasal isolates.
**Deep infection: intravenous antibiotics+further surgery.
††Patient screened twice for MSSA but no evidence of carriage.
MSSA, methicillin-susceptible Staphylococcus aureus; Neg, negative; NK, not known; Pos, positive.