Natural History of Community-Acquired Methicillin-Resistant Staphylococcus aureus Colonization and Infection in Soldiers

摘要: Background. Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is an emerging pathogen for which the prevalence, risk factors, and natural history are incompletely understood. Methods. In this prospective observational study, we evaluated 812 US Army soldiers to determine prevalence of factors CA-MRSA colonization changes in rate over time, as well clinical significance colonization. Demographic data swab samples from nares S. cultures were obtained participants at start their training 8-10 weeks later. Over time period, observed prospectively monitor soft-tissue infections. isolates characterized by vitro examination antibiotic susceptibilities, mecA confirmation, pulsed-field gel electrophoresis, Panton-Valentine leukocidin (PVL) gene testing. Results. At initial sampling, 24 (3%) colonized with CA-MRSA, 9 whom (38%) developed infections during study period. contrast, 229 (28%) methicillin-susceptible (MSSA), 8 same period (relative risk, 10.7; 95% confidence interval, 4.6-25.2; P<.001). follow-up culture, dropped 1.6% without eradication efforts. Previous use was a factor sampling (P =.03). PVL genes detected 66% 45 recovered isolates, including all available analysis. Of subjects hospitalized, 5 6 had PVL-positive Conclusions. strains associated significant infection, suggesting that may be more virulent than MSSA. play role