title: Impact of contact and droplet precautions on the incidence of hospital-acquired methicillin-resistant Staphylococcus aureus infection.
abstract: OBJECTIVE
  To evaluate the efficacy of contact and droplet precautions in reducing the incidence of hospital-acquired methicillin-resistant Staphylococcus aureus (MRSA) infections.
  
  
  METHODS
  Before-after study.Setting. A 439-bed, university-affiliated community hospital.
  
  
  METHODS
  To identify inpatients infected or colonized with MRSA, we conducted surveillance of S. aureus isolates recovered from clinical culture and processed by the hospital's clinical microbiology laboratory. We then reviewed patient records for all individuals from whom MRSA was recovered. The rates of hospital-acquired MRSA infection were tabulated for each area where patients received nursing care. After a baseline period, contact and droplet precautions were implemented in all intensive care units (ICUs). Reductions in the incidence of hospital-acquired MRSA infection in ICUs led to the implementation of contact precautions in non-ICU patient care areas (hereafter, "non-ICU areas"), as well. Droplet precautions were discontinued. An analysis comparing the rates of hospital-acquired MRSA infection during different intervention periods was performed.
  
  
  RESULTS
  The combined baseline rate of hospital-acquired MRSA infection was 10.0 infections per 1,000 patient-days in the medical ICU (MICU) and surgical ICU (SICU) and 0.7 infections per 1,000 patient-days in other ICUs. Following the implementation of contact and droplet precautions, combined rates of hospital-acquired MRSA infection in the MICU and SICU decreased to 4.3 infections per 1,000 patient-days (95% confidence interval [CI], 0.17-0.97; P=.03). There was no significant change in hospital-acquired MRSA infection rates in other ICUs. After the discontinuation of droplet precautions, the combined rate in the MICU and SICU decreased further to 2.5 infections per 1,000 patient-days. This finding was not significant (P=.43). In the non-ICU areas that had a high incidence of hospital-acquired MRSA infection, the rate prior to implementation of contact precautions was 1.3 infections per 1,000 patient-days. After the implementation of contact precautions, the rate in these areas decreased to 0.9 infections per 1,000 patient-days (95% CI, 0.47-0.94; P=.02).
  
  
  CONCLUSIONS
  The implementation of contact precautions significantly decreased the rate of hospital-acquired MRSA infection, and discontinuation of droplet precautions in the ICUs led to a further reduction. Additional studies evaluating specific infection control strategies are needed.
authors.affiliation: Department of Medicine, Weill Cornell Medical College, New York, NY 11355, USA. edm9010@nyp.org
authors.forename: Ed
authors.initials: E
authors.lastname: Mangini
authors.forename: Sorana
authors.initials: S
authors.lastname: Segal-Maurer
authors.forename: Janice
authors.initials: J
authors.lastname: Burns
authors.forename: Annette
authors.initials: A
authors.lastname: Avicolli
authors.forename: Carl
authors.initials: C
authors.lastname: Urban
authors.forename: Noriel
authors.initials: N
authors.lastname: Mariano
authors.forename: Louise
authors.initials: L
authors.lastname: Grenner
authors.forename: Carl
authors.initials: C
authors.lastname: Rosenberg
authors.forename: James J
authors.initials: JJ
authors.lastname: Rahal
mesh_terms: D003428:Cross Infection / Q000453:epidemiology* / Q000517:prevention & control; D006801:Humans; D015994:Incidence; D017053:Infection Control / Q000379:methods*; D007362:Intensive Care Units; D016106:Methicillin Resistance; D009519:New York City / Q000453:epidemiology; D011446:Prospective Studies; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000517:prevention & control; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification