Introduction Infections due to multidrug-resistant organisms are increasingly prevalent, and antimicrobial stewardship has become a priority for many healthcare organisations, including the Defence Medical Services. In military environments, infectious diseases remain a significant burden, and infections complicating the care of modern complex combat injuries are well recognised. A focus on infection prevention and control in the deployed environment is essential, and an important element of this is an antimicrobial formulary and stewardship programme. This audit analyses antimicrobial prescribing practices by military clinicians in patients admitted to UK/US Role 3 medical treatment facility in Camp Bastion, Afghanistan, relative to the UK published guidance.

Methods Retrospective case note review of all in-patient admissions during two time periods (October 2011 and October 2012). Notes were independently reviewed by an infection specialist not involved in the management of the patients.

Results 475 case notes were reviewed, of which 250 received antimicrobials. Coalition forces represented the most common patient group (131/250), with battle injury the most frequent indication (139/250) for antimicrobial prescription, followed by disease (100/250). A total of 302 antimicrobials were prescribed, with co-amoxiclav being the most frequently used antibiotic in 74% (185/250) of patients. 84.8% (212/250) were prescribed antimicrobials in line with the antimicrobial formulary. In battle injury, 93.5% (130/139) of antimicrobial prescriptions were in line with the formulary compared with 73.9% (82/111) in disease and non-battle injury patients.

Conclusions Maintaining a strong infection control effort in the deployed setting, even in a stabilised operational environment, is difficult, but our data show good compliance to the antimicrobial formulary superior to that reported in civilian hospitals. To improve this, further innovative strategies are required, combined with a continued focus on infection control basics across the full spectrum of care.