Multidrug-resistant bacterial colonization of combat-injured personnel at admission to medical centers after evacuation from Afghanistan and Iraq.

BACKGROUND: Multidrug-resistant organism (MDRO) infections, including those secondary to Acinetobacter (ACB) and extended spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae (Escherichia coli and Klebsiella species) have complicated the care of combat-injured personnel during Operations Iraqi Freedom and Enduring Freedom. Data suggest that the source of these bacterial infections includes nosocomial transmission in both deployed hospitals and receiving military medical centers (MEDCENs). Admission screening for MDRO colonization has been established to monitor this problem and effectiveness of responses to it. METHODS: Admission colonization screening of injured personnel began in 2003 at the three US-based MEDCENs receiving the majority of combat-injured personnel. This was extended to Landstuhl Regional Medical Center (LRMC; Germany) in 2005. Focused on ACB initially, screening was expanded to include all MDROs in 2009 with a standardized screening strategy at LRMC and US-based MEDCENs for patients evacuated from the combat zone. RESULTS: Eighteen thousand five hundred sixty of 21,272 patients admitted to the 4 MEDCENs in calendar years 2005 to 2009 were screened for MDRO colonization. Average admission ACB colonization rates at the US-based MEDCENs declined during this 5-year period from 21% (2005) to 4% (2009); as did rates at LRMC (7-1%). In the first year of screening for all MDROs, 6% (171 of 2,989) of patients were found colonized at admission, only 29% (50) with ACB. Fifty-seven percent of patients (98) were colonized with ESBL-producing E. coli and 11% (18) with ESBL-producing Klebsiella species. CONCLUSIONS: Although colonization with ACB declined during the past 5 years, there seems to be replacement of this pathogen with ESBL-producing Enterobacteriaceae.

Response to infection control challenges in the deployed setting: Operations Iraqi and Enduring Freedom.

BACKGROUND: Infections caused by multidrug-resistant organisms (MDROs), including Acinetobacter, have complicated the care of military personnel injured in Operations Iraqi and Enduring Freedom. Cumulative data suggest that nosocomial transmission of MDROs in deployed medical treatment facilities (MTFs) has contributed to these infections. A 2008 review of deployed MTFs identified multiple factors impeding the performance of infection prevention and control (IC) practices. In response, efforts to emphasize IC basics, improve expertise, and better track MDRO colonization were pursued. METHODS: Efforts to increase awareness and enhance IC in deployed MTFs were focused on educating leaders and deploying personnel, producing deployed IC resources, and standardizing level IV and V admission screening for MDRO colonization. A repeat mission in 2009 reviewed interval progress. RESULTS: Increased awareness and the need for emphasis on basic IC practice, including hand hygiene, use of transmission-based (isolation) precautions, and cohorting of patients, were imparted to leaders and deploying personnel through briefings, presentations, and an All Army Activities message. Enhancement of IC expertise was implemented through increased standardization of IC practice, establishment of a predeployment IC short course, an IC teleconsultation service, and dedicated Internet resources. Standardization of admission colonization screening of personnel evacuated from the combat theater was established to better define and respond to the MDRO problem. A repeat review of the deployed MTFs found overall improvement in IC practice, including clear command emphasis in the Iraqi theater of operations. CONCLUSIONS: Maintaining a strong IC effort in the deployed setting, even in a stabilized operational environment, is difficult. Use of innovative strategies to enhance expertise and practice were implemented to reduce MDRO infections.

Natural history of colonization with gram-negative multidrug-resistant organisms among hospitalized patients.

OBJECTIVE: To determine the anatomic sites and natural history of colonization with gram-negative multidrug-resistant organisms (MDROs). DESIGN: Prospective, longitudinal cohort study. SETTING: Walter Reed Army Medical Center, a 236-bed tertiary care center in Washington, DC. PATIENTS: Deployed subjects (ie, inpatients medically evacuated from Iraq or Afghanistan) or nondeployed subjects admitted to the same hospital. METHODS: Consenting patients had 6 anatomic sites cultured every 3 days for 2 weeks and then weekly. Gram-negative organisms resistant to 3 or more classes of antibiotics were considered MDROs. Isolates were genotyped using pulsed-field gel electrophoresis. Clinical data, data on antibiotic use, and clinical culture results were collected. RESULTS: Of 60 deployed subjects, 14 (23%) were colonized with an MDRO at admission, and 13 (22%) had incident colonization during hospitalization. The groin was the most sensitive anatomic site for detecting MDRO colonization, and all but one subject remained colonized for the duration of their hospitalization. Sixty percent of subjects with incident Acinetobacter colonization and 25% of subjects with incident Klebsiella colonization had strains that were related to those isolated from other subjects. Of 60 nondeployed subjects, 5 (8%) were colonized with an MDRO at admission; all had recent healthcare contact, and 1 nondeployed subject had an isolate related to a strain recovered from a deployed subject. CONCLUSIONS: Colonization with gram-negative MDROs is common among patients with war-related trauma admitted to a military hospital and also occurs among nondeployed patients with recent healthcare contact. The groin is the most sensitive anatomic site for active surveillance, and spontaneous decolonization is rare.