Surveillance of MRSA in General ICUs in Ireland in 2008

Background: The MRSA in ICU point prevalence study commenced in April 2008 following a nine month pilot study. The primary objective of the study is to provide a weekly snapshot of MRSA in the critical care setting that requires minimal additional resources. Data is fedback to participants on a quarterly basis to enable ICUs to monitor trends over time.

Objective: To review weekly prevalence data collected from 1st April to 31^st December 2008 inclusive.

Methods: A point prevalence survey captured ICU data on MRSA prevalance, bed occupancy and isolation capabilities. Weekly prevalence data were averaged over the period under study.  ICUs were stratified by ICU type; Level 2/3 ICU, containing a combination of true ICU patients and coronary care unit or high dependency unit patients and Level 3 ICU containing patients classified as ICU patients only.

Results: 32 Irish ICUs participated , 18 level 2/3 ICUs and 14 level 3 ICUs. ICU bed occupancy and isolation room occupancy rates were high in both level 2/3 (88% and 75%, respectively) and level 3 ICU groups (90% and 90%, respectively). Differences in isolation room resources were identified; four of the 32 participating ICUs had no isolation room facilities and of the remaining 28 ICUs, there are a total of 61 isolation rooms with the majority (62%) found within level 3 ICUs. Most (71%) ICUs with isolation rooms have one to two isolation rooms and all ICUs with five or more isolation rooms are level 3 ICUs. The majority of isolation rooms were found to be equipped with hand sinks (98%) but only 20% were found to have anterooms. Only two of the ICUs could successfully isolate all of their MRSA patients when surveyed. On average 21.9% of all ICU patients were isolated; another 3.8% required isolation but could not be isolated due to a lack of facilities.

All ICUs screen for MRSA colonisation on admission to ICU. However, there are differences in screening protocols between hospitals. The mean MRSA prevalence ranged from 2.9% to 21.2%, with a median of 7.8%. This reflects mostly patients colonised with MRSA upon admission to the ICU. MRSA prevalence varies widely depending on the type of ICU. The level 2/3 ICU group had a median MRSA prevalence of 5.9% with the level 3 group having a significantly higher median prevalence of 13%, (p <0.001).

Conclusions:

While there are several limitations to using a simple point prevalence surveillance tool, this project has allowed the collation of national data within current resources which have provided valuable insights into the burden of MRSA in Irish ICUs. MRSA prevalence is significantly higher in level 3 ICUs compared to level 2/3 ICUs. There is a wide variation in isolation room resources across participating ICUs. To reduce the risk of MRSA cross-infection and subsequent infection, many ICUs need refurbishment to facilitate patient isolation in accordance with best international practice.