Early Infections Complicating the Care of Combat Casualties from Iraq and Afghanistan

Abstract

Background: During the conflicts in Iraq and Afghanistan, more than 52,000 U.S. military members were wounded in action. The battlefield mortality rate was lower than in past conflicts, however, those surviving often had complex soft tissue and bone injuries requiring multiple surgeries. This report describes the rates, types, and risks of infections complicating the care of combat casualties.

Patients and methods: Infection and microbiology data obtained from the Trauma Infectious Disease Outcomes Study (TIDOS), a prospective observational study of infections complicating deployment-related injuries, were used to determine the proportion of infection, types, and associated organisms. Injury and surgical information were collected from the Department of Defense Trauma Registry. Multivariable Cox proportional hazards and logistic regression models were used to evaluate potential factors associated with infection.

Results: From 2009-2012, 1,807 combat casualties were evacuated to U.S. TIDOS-participating hospitals. Among the 1,807 patients, the proportion of overall infections from time of injury through initial U.S. hospitalization was 34% with half being skin, soft tissue, or bone infections. Infected wounds most commonly grew Enterococcus faecium, Pseudomonas aeruginosa, Acinetobacter spp. or Escherichia coli. In the multivariable model, amputation, blood transfusions, intensive care unit admission, injury severity scores, mechanical ventilation, and mechanism of injury were associated with risk of infection.

Conclusions: One-third of combat casualties from Iraq and Afghanistan develop infections during their initial hospitalization. Amputations, blood transfusions, and overall injury severity are associated with risk of infection, whereas more easily modifiable factors such as early operative intervention or antibiotic administration are not.

Keywords: combat trauma; military health; trauma-related infections; wound infections.

FIG. 1.

Proportion of infections by facility (i.e., Landstuhl Regional Medical Center [LRMC] or a participating hospital in the United States) at the time of diagnosis. ICU = intensive care unit.

FIG. 2.

Distribution of types of infections from the inpatient period at participating sites in the United States. (A) Data are on a per infection basis. Miscellaneous infections are urinary tract infections (5.7%), intra-abdominal infections (2.3%), Clostridium difficile (1.0%), sinusitis (0.6%), bronchitis (0.3%), eye infections (0.1%), and otitis (0.1%). Percentages are calculated based upon the total number of infections during the inpatient period (n = 1,514). (B) Data are on a per subject basis. Percentages are calculated based upon the total number of patients admitted to participating sites in the United Sates (n = 1,807). BSI = blood stream infection; CNS = central nervous system; MISC = miscellaneous; Osteo = osteomyelitis; SSTI = skin and soft-tissue infection.