 Previously, infection was thought to occur due to contamination with "A. baumannii" at the time of injury.Subsequent studies have shown, although "A. baumannii" may be infrequently isolated from the natural environment, the infection is more likely nosocomially acquired, likely due to the ability of "A. baumannii" to persist on artificial surfaces for extended periods, and the several facilities to which injured soldiers are exposed during the casualty-evacuation process.Injured soldiers are first taken to level-I facilities, where they are stabilized.