Temporal Trends in Donor Site Infection After Burn Injury

Authors:
Parisa Oviedo, Allison Berndtson, Laura Haines, Jeanne Lee, Jarrett Santorelli

Body of Abstract:
Background: Burn patients are vulnerable to infection due to loss of skin barrier, frequent operative procedures, broad-spectrum antibiotic exposure, and prolonged critical illness. Prior studies in burn populations demonstrate that total body surface area (TBSA) and hospitalization duration are associated with multidrug-resistant organism (MDRO) infections, but temporal patterns in burn-related infections— particularly donor site infections, a significant morbidity following autografting—remain poorly characterized. We hypothesized that the prevalence of MDRO infections and donor site infections would vary by month or season.

Methods: We performed a single-institution retrospective cohort study of burn patients admitted from 2015–2019 using a burn registry at an American Burn Association verified center. Culture positivity and organism data were recorded per patient. MDRO infection was defined as the presence of one or more organism belonging to the following resistance classes: MRSA, ESBL, CRE, or VRE. Temporal variables included admission month, quarter, and year. Associations between infection prevalence and temporal measures were assessed using chi-square testing and logistic regression, with adjustment for TBSA in multivariable models.

Results: 794 burn patients, 139 (17.5%) developed an MDRO infection. MDRO prevalence did not differ by quarter (p=0.425), and quarter was not predictive of MDRO after adjusting for TBSA (p=0.762). TBSA was a strong independent predictor of MDRO infection, with each 1% increase in TBSA associated with an 8.0% increase in odds of MDRO (OR 1.080; p<0.001). No individual MDRO resistance class demonstrated significant month- or quarter-level variation (all p>0.05). In contrast, donor site infection rates varied significantly by month (p=0.003). As shown in Figure 1, the highest monthly rate occurred in February (20.0%) and August (16.2%) and the lowest rates occurred in April (1.7%) and October (2.4%). However, donor site infection did not vary by calendar quarter (p=0.345). TBSA was not significantly associated with donor site infection (p=0.904).

Conclusion: MDRO epidemiology in burn patients remained stable across seasons and years, with burn size—not temporality—predicting MDRO risk. Donor site infections showed significant month-to-month variation that was not explained by TBSA or broader seasonal categories, underscoring the need for further study into factors contributing to this month-specific variability. Further investigation should examine organism-level trends in donor site infections if wound cultures are available, and other potential drivers of this temporal variability.