Targeted intranasal mupirocin to prevent colonization and infection by community-associated methicillin-resistant Staphylococcus aureus strains in soldiers: a cluster randomized controlled trial.

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is an emerging pathogen that primarily manifests as uncomplicated skin and soft tissue infections. We conducted a cluster randomized, double-blind, placebo-controlled trial to determine whether targeted intranasal mupirocin therapy in CA-MRSA-colonized soldiers could prevent infection in the treated individual and prevent new colonization and infection within their study groups. We screened 3,447 soldiers comprising 14 training classes for CA-MRSA colonization from January to December 2005. Each training class was randomized to either the mupirocin or placebo study group, and the participants identified as CA-MRSA colonized were treated with either mupirocin or placebo. All participants underwent repeat screening after 8 to 10 weeks and were monitored for 16 weeks for development of infection. Of 3,447 participants screened, 134 (3.9%) were initially colonized with CA-MRSA. Five of 65 (7.7%; 95% confidence interval [95% CI], 4.0% to 11.4%) placebo-treated participants and 7 of 66 (10.6%; 95% CI, 7.9% to 13.3%) mupirocin-treated participants developed infections; the difference in the infection rate of the placebo- and mupirocin-treated groups was -2.9% (95% CI, -7.5% to 1.7%). Of those not initially colonized with CA-MRSA, 63 of 1,459 (4.3%; 95% CI, 2.7% to 5.9%) of the placebo group and 56 of 1,607 (3.5%; 95% CI, 2.6% to 5.2%) of the mupirocin group developed infections; the difference in the infection rate of the placebo and mupirocin groups was 0.8% (95% CI, -1.0% to 2.7%). Of 3,447 participants, 3,066 (89%) were available for the second sampling and completed follow-up. New CA-MRSA colonization occurred in 24 of 1,459 (1.6%; 95% CI, 0.05% to 2.8%) of the placebo group participants and 23 of 1,607 (1.4%; 95% CI, 0.05% to 2.3%) of the mupirocin group participants; the difference in the infection rate of the placebo and mupirocin groups was 0.2% (95% CI, -1.3% to 1.7%). Despite CA-MRSA eradication in colonized participants, this study showed no decrease in infections in either the mupirocin-treated individuals or within their study group. Furthermore, CA-MRSA eradication did not prevent new colonization within the study group.

Acinetobacter skin colonization of US Army Soldiers.

OBJECTIVE: To evaluate whether skin colonization with Acinetobacter calcoaceticus-baumannii complex exists in a population of healthy, nondeployed US Army soldiers and, if present, how it might relate to the infections seen in current war casualties. DESIGN: We sampled various skin sites of soldiers to test for the presence of A. calcoaceticus-baumannii complex and to establish the prevalence of colonization. We then used ribotyping and antimicrobial susceptibility profiles to compare the isolates we recovered with A. calcoaceticus-baumannii complex isolates from injured soldiers. SETTING: Fort Sam Houston, Texas. PARTICIPANTS: A population of healthy, nondeployed US Army soldiers in training. RESULTS: A total of 17% of healthy soldiers were found to harbor A. calcoaceticus-baumannii complex. However, the strains differed from those recovered from injured soldiers. CONCLUSIONS: Skin carriage of A. calcoaceticus-baumannii complex exists among soldiers before deployment. However, the difference in the strains isolated from healthy soldiers, compared with the strains from injured soldiers, makes it difficult to identify skin colonization as the source of infection.