title: Duration of Colonization and Determinants of Earlier Clearance of Colonization With Methicillin-Resistant Staphylococcus aureus.
abstract: 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.
authors: Division of Infectious Diseases, Department of Medicine.
authors: Valerie C
authors: VC
authors: Cluzet
authors: Center for Clinical Epidemiology and Biostatistics Department of Biostatistics and Epidemiology Department of Pediatrics Division of Infectious Diseases, Children's Hospital of Philadelphia.
authors: Jeffrey S
authors: JS
authors: Gerber
authors: Department of Pathology and Laboratory Medicine.
authors: Irving
authors: I
authors: Nachamkin
authors: Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston.
authors: Joshua P
authors: JP
authors: Metlay
authors: Center for Clinical Epidemiology and Biostatistics Department of Biostatistics and Epidemiology Department of Pediatrics Division of Infectious Diseases, Children's Hospital of Philadelphia.
authors: Theoklis E
authors: TE
authors: Zaoutis
authors: Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
authors: Meghan F
authors: MF
authors: Davis
authors: Division of Infectious Diseases, Penn State Hershey Medical Center.
authors: Kathleen G
authors: KG
authors: Julian
authors: Department of Biology, Lincoln University, Pennsylvania.
authors: David
authors: D
authors: Royer
authors: Division of Infectious Diseases, Department of Medicine Philadelphia Veterans Administration Medical Center.
authors: Darren R
authors: DR
authors: Linkin
authors: Center for Clinical Epidemiology and Biostatistics Department of Biostatistics and Epidemiology Department of Pediatrics Division of Infectious Diseases, Children's Hospital of Philadelphia.
authors: Susan E
authors: SE
authors: Coffin
authors: Center for Clinical Epidemiology and Biostatistics Department of Biostatistics and Epidemiology Department of Dermatology, Perelman School of Medicine, University of Pennsylvania.
authors: David J
authors: DJ
authors: Margolis
authors: Department of Emergency Medicine, Thomas Jefferson University Hospital, Philadelphia.
authors: Judd E
authors: JE
authors: Hollander
authors: Section of Emergency Medicine, Children's Hospital Colorado, Aurora.
authors: Rakesh D
authors: RD
authors: Mistry
authors: Department of Emergency Medicine, Penn Presbyterian Medical Center.
authors: Laurence J
authors: LJ
authors: Gavin
authors: Center for Clinical Epidemiology and Biostatistics.
authors: Pam
authors: P
authors: Tolomeo
authors: Center for Clinical Epidemiology and Biostatistics.
authors: Jacqueleen A
authors: JA
authors: Wise
authors: Center for Clinical Epidemiology and Biostatistics.
authors: Mary K
authors: MK
authors: Wheeler
authors: Center for Clinical Epidemiology and Biostatistics Department of Biostatistics and Epidemiology.
authors: Warren B
authors: WB
authors: Bilker
authors: Center for Clinical Epidemiology and Biostatistics Department of Biostatistics and Epidemiology.
authors: Xiaoyan
authors: X
authors: Han
authors: Department of Pathology and Laboratory Medicine.
authors: Baofeng
authors: B
authors: Hu
authors: Division of Infectious Diseases, Department of Medicine.
authors: Neil O
authors: NO
authors: Fishman
authors: Division of Infectious Diseases, Department of Medicine Center for Clinical Epidemiology and Biostatistics Department of Biostatistics and Epidemiology.
authors: Ebbing
authors: E
authors: Lautenbach
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D015995:Prevalence; D011446:Prospective Studies; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology*; D013997:Time Factors; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents
keywords: MRSA colonization; MRSA decolonization; MRSA skin and soft-tissue infection; methicillin-resistant Staphylococcus aureus (MRSA)
references: Infect Control Hosp Epidemiol. 2009 Apr;30(4):380-2
references: 19239378
references: J Pediatric Infect Dis Soc. 2013 Jun;2(2):147-54
references: 23717786
references: Scand J Infect Dis. 2006;38(10):888-93
references: 17008233
references: Infect Control Hosp Epidemiol. 2001 Nov;22(11):687-92
references: 11842988
references: Scand J Infect Dis. 2011 Jul;43(6-7):456-62
references: 21366406
references: Health Aff (Millwood). 2012 Jan;31(1):199-207
references: 22232111
references: Clin Infect Dis. 2009 Apr 1;48(7):910-3
references: 19231982
references: Clin Infect Dis. 2001 May 15;32(10):1393-8
references: 11317238
references: Am J Med. 1996 May;100(5):509-16
references: 8644762
references: Clin Infect Dis. 2007 Jan 15;44(2):178-85
references: 17173213
references: Clin Infect Dis. 1994 Dec;19(6):1123-8
references: 7888543
references: Infect Control Hosp Epidemiol. 2003 Jun;24(6):422-6
references: 12828318
references: Infect Control Hosp Epidemiol. 2004 Feb;25(2):114-20
references: 14994935
references: Am J Infect Control. 2009 Mar;37(2):106-10
references: 18945520
references: Emerg Infect Dis. 2005 Jun;11(6):928-30
references: 15963289
references: Clin Infect Dis. 2004 Oct 1;39(7):971-9
references: 15472848
references: Clin Infect Dis. 2003 Jan 15;36(2):131-9
references: 12522744
references: J Clin Microbiol. 2005 Dec;43(12):5992-5
references: 16333087
references: J Antimicrob Chemother. 2011 Oct;66(10):2409-17
references: 21719473
references: J Infect Chemother. 2013 Oct;19(5):806-11
references: 23377557
references: J Med Microbiol. 2007 Jan;56(Pt 1):43-6
references: 17172515
references: Arch Pediatr Adolesc Med. 2012 Jun 1;166(6):551-7
references: 22665030
references: Antimicrob Agents Chemother. 1998 Jul;42(7):1762-70
references: 9661018
references: Arch Intern Med. 2009 Aug 10;169(15):1372-8
references: 19667299
references: J Am Board Fam Med. 2010 Nov-Dec;23(6):714-9
references: 21057066
references: Clin Infect Dis. 2012 Mar;54(6):743-51
references: 22198793
references: N Engl J Med. 2001 Jan 4;344(1):11-6
references: 11136954
references: Infect Control Hosp Epidemiol. 2006 Nov;27(11):1206-12
references: 17080378
references: Clin Infect Dis. 2013 Nov;57(10):1458-60
references: 23943821
references: J Clin Microbiol. 2011 Mar;49(3):1119-21
references: 21209169
references: Clin Infect Dis. 2004 Sep 15;39(6):776-82
references: 15472807
references: J Clin Microbiol. 2010 Jan;48(1):202-7
references: 19923490
references: Am J Epidemiol. 1993 Dec 1;138(11):923-36
references: 8256780
references: Infect Control Hosp Epidemiol. 2006 Feb;27(2):181-4
references: 16465635
references: Lancet Infect Dis. 2005 May;5(5):275-86
references: 15854883