Superficial swab cultures in open fracture management: insights from a resource-poor setting

Abstract

To identify bacterial isolates from superficial swabs of open fracture wounds at presentation and after infection has been established, and to determine if there are correlations between them. Patients who presented with open fractures at the Wesley Guild Hospital, Ilesa, Nigeria between December 2004 and May 2006 were recruited into this prospective study. Superficial wound swabs were taken at presentation and if patient showed evidence of wound infection. Sixty patients had open fractures. The initial bacteria culture of wound swabs taken on the day of presentation was positive in 41 (68.3%) patients. Of these, 19 (46.3%) yielded one bacteria isolate, 17 (41.5%) yielded two and 5 (12.2%) yielded three, making a total of 68 organisms. The most common organism was Staphylococcus aureus. However, as a group, more aerobic Gram-negative rods were isolated than any other bacteria groups. Eleven (18.3%) patients developed wound infections, all of which were polymicrobial. In 10 (90.9%) of these, the microbial isolate of the final wound swab included at least one organism that was present in the initial wound culture. No patient with an initial negative culture went on to develop a wound infection. The mean presentation interval of patients with wounds that became infected was 15.2 ± 7.9 hours (95% CI 9.8-20.5 hours) compared with 2.9 ± 3.1 hours (95% CI 2.0-3.8 hours) for those who did not develop a wound infection (p>0.01). In a resource-poor setting, where pre-hospital care is unavailable and patients present late, superficial wound swabs are effective in predicting subsequent organisms that may cause wound infections. None.