Predictors of multi-drug resistance in burn wound colonization following burn injury in a resource-limited setting

Bacterial resistance to antibiotics is growing dramatically worldwide due to several contributing factors, including inappropriate antibiotic utilization in the clinical setting and widespread use in the food production industry. Consequently, it is imperative to characterize antibiotic resistance in high-risk populations, such as burn patients, particularly in resource-limited settings where prevention strategies may be high-yield and new antibiotics are not readily available. We therefore sought to characterize and identify predictors of multi-drug resistant (MDR) bacteria colonization in burn patients at our center in Malawi.

This is a prospective analysis of burn patients presenting to Kamuzu Central Hospital in Lilongwe, Malawi within 72 h of burn injury. A swab of each patient's primary wound was collected at admission and each subsequent week. The primary aim was to determine predictors of colonization in burn wounds with multi-drug resistant bacteria using modified Poisson regression modeling.

99 patients were enrolled and analyzed. The median age was 4 years (IQR 2-12) with a median % total burn surface area (TBSA) of 14% (IQR 9-25). The most common burn injury type was scald (n = 61, 61.6%), followed by flame (n = 37, 37.4%). Overall, 54 patients (54.6%) were colonized with MDR bacteria at some point during their hospitalization, with increases each week. For flame burns, the predictors of MDR bacterial colonization were each 1% increase of %TBSA (RR 1.01, 95% CI 1.00, 1.03, p = 0.038) and the use of operative intervention for burn treatment (RR 1.90, 95% CI 1.17, 3.09, p = 0.010). No variables were predictive of MDR wound colonization in scald burns.

Our study identified that almost half of the patients in a Malawian burn unit had MDR bacteria colonizing burn wounds after only a week in the hospital. This increased to almost 70% during hospitalization. We also found that for patients with flame burns, increasing %TBSA, and operative intervention put patients at greater risk of MDR colonization. Interventions such as isolation of burn patients, consistent disinfection and sterilization of wards and operating rooms, and optimization of wound care management are imperative to decrease spread of MDR bacteria and to improve burn-associated clinical outcomes in resource-limited environments.