Healthcare-associated pneumonia among U.S. combat casualties, 2009 to 2010

Although there is literature evaluating infectious complications associated with combat-related injuries from Iraq and Afghanistan, none have evaluated pneumonia specifically. Therefore, we assessed a series of pneumonia cases among wounded military personnel admitted to Landstuhl Regional Medical Center, and then evacuated further to participating U.S. military hospitals. Of the 423 casualties evacuated to the United States, 36 developed pneumonia (8.5%) and 30 of these (83.3%) were ventilator-associated. Restricting to 162 subjects admitted to intensive care, 30 patients had pneumonia (18.5%). The median Injury Severity Score was higher among subjects with pneumonia (23.0 vs. 6.0; p < 0.01). There were 61 first-isolate respiratory specimens recovered from 31 pneumonia subjects, of which 56.1% were gram-negative, 18.2% were gram-positive, and 18.2% were fungal. Staphylococcus aureus and Pseudomonas aeruginosa were most commonly recovered (10.6%, and 9.1%, respectively). Thirteen bacterial isolates (26.5%) were multidrug-resistant. Outcome data were available for 32 patients, of which 26 resolved their infection without progression, 5 resolved after initial progression, and 1 died. Overall, combat-injured casualties suffer a relatively high rate of pneumonia, particularly those requiring mechanical ventilation. Although gram-negative pathogens were common, S. aureus was most frequently isolated. Continued focus on pneumonia prevention strategies is necessary for improving combat care.