When Should Contact Precautions be Discontinued for Patients with Methicillin-Resistant Staphylococcus aureus (MRSA)
Methods: From 10/2010 - 3/2014 we prospectively performed admission ASC (and weekly for those with (-) results) on pts known to have been MRSA (+) for at least 1 year to determine the proportion who remained MRSA (+). Characteristics (age, sex, race, hospitalization within the year, presence of a wound or foreign body, receipt of antibiotics, hemodialysis, and residence in a group setting) were collected from a chart review to determine factors associated with persistent carriage.
Results: Over the study period 408 pts with MRSA had an admission ASC done a mean of 1671 days from their first known (+) MRSA culture (range 416 - 5668 days). Ultimately, 82 (20.1%) pts in the cohort had MRSA detected during the study. 68 (16.7%) of 408 had a (+) admission ASC. Of the 339 pts who had a (-) admission ASC, 181 (53.4%) had a second ASC culture and 8 (4.4%) were (+) for MRSA. Of the 173 pts who had two (-) ASC, 6 (3.5%) went on to have a future culture (+) for MRSA.
Increased number of days between first known (+) MRSA culture to admission ASC was associated with a lower risk for having MRSA detected during the study (p= 0.04) and having the ASC performed more than 5 years since the first known (+) MRSA culture was associated with the lowest risk (OR 0.45, [0.25-0.79], p=0.005). For example, 18 (12.5%) of 144 pts with an ASC done more than 5 years from their first known (+) MRSA vs 64 (24.2%) of 264 pts with an ASC done 5 years or less from their first known (+) MRSA culture had MRSA detected during the study. Presence of a foreign body significantly increased the risk for having a (+) MRSA culture (OR 1.36 [1.02-1.82], p= 0.05) and female sex significantly reduced the risk (OR 0.78 [0.60-1.00], p=0.05).
Conclusion: The proportion of pts with MRSA documented more than a year ago who remained (+) was 20.1% however this significantly decreased over time, particularly after 5 years. Our data also suggest that in the absence of a foreign body and especially among females, CP can be discontinued after one (-) admission ASC.
M. Engle, None
L. Formby, None
L. Richey, None
C. Salgado, Wolters Kluwer Health: Editorial Assistance, Licensing agreement or royalty