Operation Enduring Freedom and Operation Iraqi Freedom

More than 16,600 military personnel deployed to OEF and OIF have suffered nonmortal wounds (Defense Manpower Data Center 2006). Many of these troops lost limbs or parts of limbs as a result of explosions that caused traumatic or surgical amputation (Davis et al. 2005). Soil- and water-dwelling bacteria, including Acinetobacter baumanii, have colonized and infected many soldiers’ amputation sites and other blast wounds (Zapor and Moran 2005). Indeed, orthopedic war wounds have become the most common reason for infectious-disease consultations since September 2001 at WRAMC (Zapor and Moran 2005). Cultured specimens from wounds have often implicated a multiple-drug-resistant strain of A. baumanii (Zapor and Moran 2005).

A. baumanii has long been a cause of nosocomial infections. Infected battle injuries from OEF and OIF, however, have increased the rate of bloodstream infections by A. baumanii by more than 2,000% at two major US military hospitals (Table 4.14) (CDC 2004c). Moreover, some strains of A. baumanii have demonstrated resistance to all but one antimicrobial agent in the present pharmacologic arsenal—colistin, a toxic drug (CDC 2004c).

The active-duty military personnel described below, who were generally young and healthy before sustaining war wounds, usually recovered from A. baumanii infection after receiving medical treatment.

TABLE 4.14 Increase in Incidence of A. baumannii Bloodstream Infections at Two Military Hospitals, 2000-2004

 

No. Cases

 

Hospital

pre-2003

January 2003-August 2004

Percentage Increase in No. Cases

Walter Reed Army Medical Center

2 (2001-2002)

45

2,150

Landstuhl Regional Medical Center

1 (2000-2002)

33

3,200

SOURCE: Scott et al. 2004.

Case Series 1:
Brooke Army Medical Center

From March 1, 2003, to May 31, 2004, Brooke Army Medical Center (BAMC), in Houston, Texas admitted 151 injured active-duty soldiers who had been deployed to OEF or OIF (Davis et al. 2005). Davis and colleagues report that all patients but one had previously been admitted to Landstuhl Regional Medical Center (LRMC) in Landstuhl, Germany; three had also been admitted to a second US Army medical facility before BAMC.

Of the tissue samples obtained from 84 of those patients, 48 (32%) tested positive for Acinetobacter calcoaceticus-baumanii complex; 30 patients (63% of those colonized) were clinically infected, and 23 met the case definition for either Acinetobacter osteomyelitis or Acinetobacter wound infection (Table 4.15). None had been diagnosed with Acinetobacter spp. before evacuation from Iraq or Afghanistan.

All but one of the 23 patients with Acinetobacter osteomyelitis or Acinetobacter wound infection received parenteral antimicrobial drug treatment selected to match the susceptibility of the infecting A. baumanii strain (Table 4.16). The primary therapeutic challenge was antimicrobial resistance. Most patients with Acinetobacter osteomyelitis underwent a 6- to 8-week course of drug therapy complemented by multiple surgical debridements of necrotic bone; one patient was treated with surgical debridement alone. Drug therapy for 10 of the osteomyelitis patients involved two antimicrobials, usually imipenem and amikacin. In contrast, patients with



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement