Cross-Border Antibiotic Resistance Patterns in Burn Patients

Author(s):
Chance Dunbar; Jarrett Santorelli; William Marshall; Laura Haines; Kevin Box; Jeanne Lee; Eli Strait; Todd Costantini; Alan Smith; Jay Doucet; Allison Berndtson

Background:

Antimicrobial resistance (AMR) is a growing problem worldwide, with differences in regional resistance patterns partially driven by local variance in antibiotic stewardship. Resistant gram-negative organisms are increasingly prevalent in Latin America and account for a higher percentage of infections than in the United States (USA) or Canada. Trauma patients transferring from Mexico (MEX) for treatment have been shown to have more AMR than those injured in the USA, raising concern for transfer of AMR across the border.

Hypothesis:

Patients transferred to a USA burn center after burn injury in Mexico have a higher incidence of infections due to antibiotic-resistant organisms.

Methods:

The registry of an ABA verified burn center was queried for all admissions for burn injury Jan 2015 – Dec 2019. Patients were excluded if they had a hospital length of stay (LOS) of <7 days. Patients were divided into two groups based upon injury location: inside the USA or in MEX. Cultures and sensitivities were reviewed to remove duplicate results and for confirmation of clinical infection.  All non-wound infections were analyzed.

Results:

A total of 69 MEX and 833 USA patients were included.  Patients had a similar mean age (40.7 years MEX vs. 42.1 years USA) and sex distribution (69.6% male MEX vs 64.3% USA).  MEX patients had a larger mean %TBSA burn (17.2% vs. 8.3%), primarily flame burns (49.3% vs. USA 38.9% flame and 36.1% scald) and longer hospital LOS (26.6 vs. 19.2 days).  MEX patients were more likely to have any infection (20.3% vs. 11.4%), urinary infections (7.3% vs. 3.4%), and respiratory infections (15.9% vs. 7.4%), while bloodstream infections were similar.  MEX patients had more gram-positive infections (38.9% vs. 32.0%) as well as more resistant infections (38.9% of all organisms grown vs. 19.5%, p=0.027).

Conclusions:

AMR is more common in burn patients injured in MEX and transported across the border than in those injured in the USA, despite geographic proximity. Patients from high AMR areas including MEX may require alternative empiric antibiotic regimens when presenting with infection. Global initiatives to improve antibiotic stewardship are critical.