Infections Following Skin Graft Surgery at Two Regional Centres ‐ Characteristics, Risk Factors and Microbiology of Infection

Background: Skin grafts including split-thickness skin grafts (SSG) and full-thickness skin grafts (FTSG) are widely used in reconstructive surgery. Infection following grafting can compromise graft take and prolong hospitalisation, yet contemporary cohort data describing incidence, microbiology and graft-specific risk factors remain limited. Methods: We conducted a retrospective observational cohort study of 977 consecutive skin graft procedures performed in 116 patients at two hospitals in New South Wales, Australia, between 1 July 2021 and 13 August 2024. Post-graft infection was defined as a clinician-diagnosed graft site infection with microbiological confirmation. Infection incidence was estimated with exact 95% confidence intervals. Associations between graft characteristics and infection were explored using chi-square testing and binomial regression to estimate relative risks. Length of stay (LOS) was assigned to the index admission corresponding to each procedure and analysed using negative binomial regression to account for overdispersion. Results: Among 977 graft procedures, 66 infections occurred, giving an overall infection incidence of 6.8% (95% CI 5.3–8.5%). Median LOS was substantially longer in infected cases than non-infected cases (34 vs 3 days, p < 0.001). Full-thickness grafts to the face (RR 0.083, 95% CI 0.008–0.827) and nose (RR 0.038, 95% CI 0.004–0.378) were associated with a reduced incidence of infection, although estimates were imprecise because of sparse data. Among infections, Staphylococcus aureus accounted for approximately 47% of cases and Pseudomonas aeruginosa for approximately 20%. In a nested antimicrobial audit cohort of 111 split-thickness skin graft procedures, peri-operative prophylaxis was common, postoperative antibiotics were frequently prescribed, and postoperative antibiotic prescribing was not associated with reduced infection, although the analysis was underpowered. Conclusions: Post-graft infection occurred in 6.8% of procedures. This rate is comparable with contemporary literature and was associated with substantial morbidity. S. aureus and P. aeruginosa predominated. These findings support consideration of targeted preventive strategies, microbiology-informed empiric therapy and antimicrobial stewardship, while highlighting the need for prospective studies with more comprehensive risk adjustment.