Are hygiene standards useful in assessing infection risk?
BACKGROUND
We monitored the surface level cleanliness in a 5-bed surgical intensive care unit (SICU) over a 10-week period to evaluate proposed hygiene standards.


METHODS
Ten environmental sites within the SICU were sampled twice weekly, along with collection of clinical and patient activity data. The standards designate aerobic colony counts (ACCs) > 2.5 colony-forming units/cm(2) from hand-touch sites and the presence of Staphylococcus aureus as indicating hygiene failure.


RESULTS
Nearly 25% of the 200 samples analyzed did not meet the standards, mostly from hand-touch sites on curtains, beds, and medical equipment. The total number of failures each week was associated with bed occupancy (P = .04), with a trend toward association with SICU-acquired infection (P = .11). Environmental S aureus was associated with the proportion of beds occupied (P = .02). Indistinguishable genotypes were found between patient and environmental staphylococci, with time scales supporting staphylococcal transmission in both directions.


CONCLUSIONS
Hygiene standards based on microbial growth levels and the presence of S aureus reflect patient activity and provide a means to risk-manage infection. They also expose a staphylococcal reservoir that could represent a more tangible risk to patients. Standards for surface level cleanliness merit further evaluation.
Department of Microbiology, Southern General Hospital, Glasgow, Scotland.
Liza F
LF
White
Stephanie J
SJ
Dancer
Chris
C
Robertson
John
J
McDonald
D003428:Cross Infection / Q000517:prevention & control*; D004784:Environmental Monitoring; D006801:Humans; D006920:Hygiene / Q000592:standards*; D017053:Infection Control / Q000379:methods*; D007362:Intensive Care Units; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000382:microbiology / Q000517:prevention & control*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification