Quantification and Bioburden of High Frequency Touch Surfaces (HFTS) in ICU Patient Rooms
Contaminated environmental surfaces serve as reservoirs of pathogens causing health care-associated infections by transient carriage on hands of healthcare personnel (HCP). We chose to quantify contact of high frequency touch surfaces (HFTS) by HCP using direct observation & assessed bioburden on these before & after direct contact.
Direct observation was conducted in a total of 10 ICU rooms (medical & surgical). Number of touches by discipline were quantified for two four hour periods per room. Quantitative environmental microbiologic samples of each HFTS were collected prior to & after disinfection & then 24+/-2 hours after first sample. Relation between number of touches on a particular surface & bioburden were analyzed using non-parametric Spearman Rank Correlation Coefficient. Differences in touch frequency & bioburden between MICU & SICU were assessed using Kruskal-Wallace test.
In the SICU, mean number of touches/shift were computer mouse/keyboard (115.6), bed rail (65.4), infusion pump (63.2), mechanical ventilator controls (41.4) & door knob (21.4). MICU touch means were: bed rail (148.2), ventilator controls (73.8), nurse server (55.4), infusion pump (45.8) & handwashing station (24.8). Mean number of touches/nursing shift were (294.6) followed by respiratory therapist (69.6), visitor (54.0), physician (28.6), & patient care assistant (23.5).
MICU had a greater total bioburden than SICU (p=0.0123). Bioburden (CFU / in 2) was only significantly higher at 24 hours after initial disinfection (p<0.0001). Post-hoc test correcting for multiple comparisons showed that pre cleaning cardiac monitors had less bioburden than other surfaces (p=0.0260). Ventilator controls had more bioburden pre and 24 hours post cleaning (p=0.0182 & p=0.039). The only pathogen cultured from any surface was Enterococcus species & the nurse server in MICU had significantly higher concentration compared to others (p=0.0026).
Conclusion: Computer mouse/keyboards, bed rails & mechanical ventilators were touched most often/shift of 14 different HFTS. Level of contamination correlated with frequency of touches but only at 24hrs after initial disinfection. Targeted disinfection of HFTS is an important infection control measure.
A. Nearhood, None
G. Siedlaczek, None
V. Moudgal, None
R. Olmsted, Ethicon: Speaker's Bureau, Speaker honorarium
Premier Inc: Consultant, Consulting fee