Assessing the role of undetected colonization and isolation precautions in reducing Methicillin-Resistant Staphylococcus aureustransmission in intensive care units

Table 2 Observed prevalence and incidence for the study data

Ward^a	Monthly MRSA prevalence^b Mean (SD)	Monthly MRSA admission prevalence^c Mean (SD)	Monthly MRSA incidence density (new cases per 1,000 patient days) Mean (SD)
M1	16.9 (4.0)	12.6 (3.0)	8.8 (8.1)
M2	23.5 (4.7)	20.6 (3.3)	5.8 (5.8)
GS1	20.5 (5.8)	15.4 (4.2)	9.3 (8.3)
GS2	19.5 (6.4)	10.9 (4.1)	18.2 (9.7)
SS1	21.1 (8.7)	12.9 (7.5)	9.8 (10.1)
SS2	13.8 (4.4)	7.3 (2.8)	6.8 (4.9)
SS3	10.7 (3.9)	6.3 (3.6)	9.4 (7.9)
SS4	9.2 (3.3)	4.5 (3.1)	9.1 (6.1)

^a Here M denotes Medical or Cardiac ICU, GS denotes General Surgical ICU, including trauma and burn patients, SS denotes Specialty Surgical ICU.
^b The number of ICU patients ever known to be MRSA-positive before or during that month, divided by the total number of ICU patients that month.
^c The number of patients ever known to be MRSA positive before or within two calendar days of admission, divided by the total number of monthly admissions.

ISSN: 1471-2334