Open Access Highly Accessed Research article

Multi-drug resistant Acinetobacter infections in critically injured Canadian forces soldiers

Homer C Tien12*, Anthony Battad2, Elizabeth A Bryce3, Jeffrey Fuller4, Michael Mulvey5, Kathy Bernard5, Ronald Brisebois26, Jay J Doucet27, Sandro B Rizoli18, Robert Fowler8 and Andrew Simor9

Author Affiliations

1 The Trauma Program, and the Department of Surgery, Sunnybrook Health Sciences Centre, H186-2075 Bayview Avenue, Toronto, Canada, M4N 3M5

2 1st Canadian Field Hospital, CFB Petawawa, Petawawa, Ontario, Canada

3 Department of Pathology and Laboratory Medicine, Vancouver General Hospital, Vancouver, Canada

4 Department of Laboratory Medicine and Pathology, University of Alberta Hospital, Edmonton, Canada

5 Nosocomial Infections and Antimicrobial Resistance Laboratory, National Microbiology Laboratory, Winnipeg, Canada

6 Departments of Surgery and Critical Care Medicine, University of Alberta Hospital, Edmonton, Canada

7 Department of Surgery, Vancouver General Hospital, Vancouver, Canada

8 Department of Critical Care Medicine, Sunnybrook Health Sciences Centre, Toronto, Canada

9 Department of Microbiology, Sunnybrook Health Sciences Centre, Toronto, Canada

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BMC Infectious Diseases 2007, 7:95  doi:10.1186/1471-2334-7-95

Published: 14 August 2007

Abstract

Background

Military members, injured in Afghanistan or Iraq, have returned home with multi-drug resistant Acinetobacter baumannii infections. The source of these infections is unknown.

Methods

Retrospective study of all Canadian soldiers who were injured in Afghanistan and who required mechanical ventilation from January 1 2006 to September 1 2006. Patients who developed A. baumannii ventilator associated pneumonia (VAP) were identified. All A. baumannii isolates were retrieved for study patients and compared with A. baumannii isolates from environmental sources from the Kandahar military hospital using pulsed-field gel electrophoresis (PFGE).

Results

During the study period, six Canadian Forces (CF) soldiers were injured in Afghanistan, required mechanical ventilation and were repatriated to Canadian hospitals. Four of these patients developed A. baumannii VAP. A. baumannii was also isolated from one environmental source in Kandahar – a ventilator air intake filter. Patient isolates were genetically indistinguishable from each other and from the isolates cultured from the ventilator filter. These isolates were resistant to numerous classes of antimicrobials including the carbapenems.

Conclusion

These results suggest that the source of A. baumannii infection for these four patients was an environmental source in the military field hospital in Kandahar. A causal linkage, however, was not established with the ventilator. This study suggests that infection control efforts and further research should be focused on the military field hospital environment to prevent further multi-drug resistant A. baumannii infections in injured soldiers.