Improved and more frequent cleanings, particularly in common areas, may result in reduced methicillin-resistant Staphylococcus aureus environmental contamination in nursing homes, according to recent study results.
In a prospective study of cleaning practices and environmental contamination, researchers examined 10 California nursing homes for the prevalence of methicillin-resistant S. aureus (MRSA). Based upon previous data collection, the homes were categorized as high- (n=6) and low-delta (n=4) prevalence for their differences in MRSA point and admission prevalence. Nares swabs were collected and analyzed for MRSA positivity from 100 residents during one visit (point prevalence) and from 100 consecutive residents at admission (admission prevalence) for each nursing home.
The researchers applied black light marks, visible under ultraviolet light, to 50 high-touch objects in common areas, and they evaluated the items for infection control and cleaning. They also marked 10 similar objects on six occasions at each nursing home and checked the next day to see if the marks had been removed by cleaning.
Of the 500 cultured swabs, 16% were MRSA positive, with a greater percentage found in the high-delta prevalence nursing home group compared with the low-delta group (19% vs. 10%, P=.005). Among the 577 evaluable UV-visible cleaning marks, 22% had been removed. There were minimal differences in mark removal between the high- and low-delta prevalence groups (23% compared with 21%, P=.62).
Using multivariate analysis the researchers found statistical significance between MRSA-positive objects and high-delta prevalence nursing homes (OR=2.8; 95% CI, 1.4-5.9), less time cleaning each room (OR=2.9; 95% CI, 1.5-5.4), and lower frequency of cleaning common areas (OR=1.5; 95% CI, 1.1-2.0).
“Environmental MRSA contamination was highly variable between 10 nursing homes, and higher MRSA contamination levels of nursing home fomites were associated with a larger number of MRSA carriers at point prevalence than at admission prevalence,” the researchers concluded. “Interventions to reduce environmental MRSA in nursing homes should consider increasing the time spent cleaning per room and improving cleaning in common areas where residents routinely congregate.”