title: Cohorting based on nasal methicillin-resistant Staphylococcus aureus status: an opportunity to share more than a room.
abstract: BACKGROUND
  Hospital roommates are cohorted with similarly colonized patients to decrease methicillin-resistant Staphylococcus aureus (MRSA) transmission risk. However, little is known about differences in S aureus nasal and extranasal carriage between hospital roommates who are in MRSA or non-MRSA designated rooms.
  
  
  METHODS
  Patients sharing hospital rooms were cultured for S aureus in the nose, throat, and other body sites. Differences in S aureus methicillin and mupirocin susceptibility and USA300 type were evaluated.
  
  
  RESULTS
  Eighty-two patients comprising 48 roommate pairs were studied. Among 6 roommate pairs in MRSA rooms, 3 (50%) had differences in carriage based on having methicillin-susceptible S aureus at an extranasal body site. In non-MRSA rooms, 19 (45%) roommate pairs had differences in S aureus carriage. Extranasal colonization was significantly associated with discordance between roommates, P < .001. Antibiotic exposure, ward type, and the duration of room sharing were not associated with discordance.
  
  
  CONCLUSIONS
  Patients have almost a 50% chance of having differences in S aureus colonization compared with their hospital roommate, even in MRSA-designated rooms. Cohorting by MRSA status at the time of admission may not be as effective a control strategy as horizontal measures that do not rely on known colonization with S aureus or other pathogens.
authors.affiliation: Department of Medicine, VA Boston HCS, Boston, MA, USA.
authors.forename: Dima
authors.initials: D
authors.lastname: Kabbani
authors.forename: Susan K
authors.initials: SK
authors.lastname: Weir
authors.forename: Gretchen
authors.initials: G
authors.lastname: Berg
authors.forename: Gina C
authors.initials: GC
authors.lastname: Chien
authors.forename: Judith
authors.initials: J
authors.lastname: Strymish
authors.forename: Kalpana
authors.initials: K
authors.lastname: Gupta
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D058345:Asymptomatic Infections; D003428:Cross Infection / Q000188:drug therapy; D006760:Hospitalization; D006761:Hospitals; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000302:isolation & purification*; D016712:Mupirocin / Q000627:therapeutic use; D009296:Nasal Cavity / Q000382:microbiology*; D010362:Patients' Rooms; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000188:drug therapy*
chemical_list: D000900:Anti-Bacterial Agents; D016712:Mupirocin