Duration of Colonization and Determinants of Earlier Clearance of Colonization With Methicillin-Resistant Staphylococcus aureus.

TitleDuration of Colonization and Determinants of Earlier Clearance of Colonization With Methicillin-Resistant Staphylococcus aureus.
Publication TypeJournal Article
Year of Publication2015
AuthorsCluzet VC, Gerber JS, Nachamkin I, Metlay JP, Zaoutis TE, Davis MF, Julian KG, Royer D, Linkin DR, Coffin SE, Margolis DJ, Hollander JE, Mistry RD, Gavin LJ, Tolomeo P, Wise JA, Wheeler MK, Bilker WB, Han X, Hu B, Fishman NO, Lautenbach E
JournalClin Infect Dis
Date Published05/2015

BACKGROUND: The duration of colonization and factors associated with clearance of methicillin-resistant Staphylococcus aureus (MRSA) after community-onset MRSA skin and soft-tissue infection (SSTI) remain unclear.

METHODS: We conducted a prospective cohort study of patients with acute MRSA SSTI presenting to 5 adult and pediatric academic hospitals from 1 January 2010 through 31 December 2012. Index patients and household members performed self-sampling for MRSA colonization every 2 weeks for 6 months. Clearance of colonization was defined as negative MRSA surveillance cultures during 2 consecutive sampling periods. A Cox proportional hazards regression model was developed to identify determinants of clearance of colonization.

RESULTS: Two hundred forty-three index patients were included. The median duration of MRSA colonization after SSTI diagnosis was 21 days (95% confidence interval [CI], 19-24), and 19.8% never cleared colonization. Treatment of the SSTI with clindamycin was associated with earlier clearance (hazard ratio [HR], 1.72; 95% CI, 1.28-2.30; P < .001). Older age (HR, 0.99; 95% CI, .98-1.00; P = .01) was associated with longer duration of colonization. There was a borderline significant association between increased number of household members colonized with MRSA and later clearance of colonization in the index patient (HR, 0.85; 95% CI, .71-1.01; P = .06).

CONCLUSIONS: With a systematic, regular sampling protocol, duration of MRSA colonization was noted to be shorter than previously reported, although 19.8% of patients remained colonized at 6 months. The association between clindamycin and shorter duration of colonization after MRSA SSTI suggests a possible role for the antibiotic selected for treatment of MRSA infection.

Alternate JournalClin. Infect. Dis.
PubMed ID25648237
PubMed Central IDPMC4490328
Grant ListK24-AI080942 / AI / NIAID NIH HHS / United States
U54-CK000163 / CK / NCEZID CDC HHS / United States