Microbiology of combat-related extremity wounds: Trauma Infectious Disease Outcomes Study

Abstract

We present extremity wound microbiology data from 250 combat casualties (2009-2012). Confirmed extremity wound infections (EWIs) were based on clinical and laboratory findings. Suspected EWIs had isolation of organisms from wound cultures with associated signs/symptoms not meeting clinical diagnostic criteria. Colonized wounds had organisms isolated without any infection suspicion. A total of 335 confirmed EWIs (131 monomicrobial and 204 polymicrobial) were assessed. Gram-negative bacteria were predominant (57% and 86% of monomicrobial and polymicrobial infections, respectively). In polymicrobial infections, 61% grew only bacteria, while 30% isolated bacteria and mold. Multidrug resistance was observed in 32% of isolates from first monomicrobial EWIs ±3 days of diagnosis, while it was 44% of isolates from polymicrobial EWIs. Approximately 96% and 52% of the suspected and colonized wounds, respectively, shared ≥1 organism in common with the confirmed EWI on the same patient. Understanding of combat-related EWIs can lead to improvements in combat casualty care.

Keywords: Extremity infections; Extremity wounds; Open fractures; Trauma-related infections; Wound microbiology.

Figure 1

Flow diagram of extremity wound infection study population. Confirmed extremity wound infections (EWIs) were based on a combination of clinical and laboratory findings and classified in accordance with standardized definitions from the National Healthcare Safety Network. Patients with confirmed EWIs also had organisms recovered from other wounds (not confirmed to be EWI) with the results being a suspected EWI or colonization. Suspected infections were defined as wound cultures with positive growth, along with signs or symptoms of a wound infection, but did not meet clinical diagnostic criteria. Colonization was defined as organism recovery from wounds without any sign or symptom of infection.