
Methods: A prospective, case-control study of SSTI was conducted among Army trainees at Fort Benning, GA to determine overall and MRSA SSTI incidence, and to describe the clinical characteristics of and risk factors for disease. Clinical specimens were processed by standard methods, and S. aureusisolates underwent further molecular characterization, including pulsed-field gel electrophoresis (PFGE). Demographic and risk factor information was collected by questionnaire.
Results: From July 2012 through December 2014, 52,261 trainees completed 14-week Infantry training. Of those trainees, 2,007 developed SSTI for an overall rate of 0.04 per 100 person-days. The MRSA SSTI rate was 0.01 per 100 person-days. Rates of SSTI were highest during the summer months. The median interval from training start to clinical presentation for SSTI was 41 days (Range 0-108). The most frequent clinical manifestations of SSTI were cellulitis (43.6%) and abscess (25.2%). The majority (61%) of infections were on the lower extremities. Of the 2,007 trainees with SSTI, 818 clinical cultures were obtained. Of these, 690 (84%) were culture-positive for S. aureus; 373 (54%) were MRSA. Of the 292 MRSA isolates available for analysis, 265 (91%) were pulsed-field type USA300. Trainees who had a known or suspected SSTI prior to arrival at Fort Benning were more likely to have an SSTI during training (Odds Ratio [OR]: 5.2), as were individuals who had contact with a person with SSTI at Fort Benning (OR: 2.02).
Conclusion:

C. Schlett,
None
J. Bennett, None
E. Elassal, None
N. Law, None
S. Dowlen, None
D. Lyles, None
A. Hadley, None
M. Ellis, None