Study finds MRSA, VRE co-colonization is common in nursing homes

A study by researchers from the University of Michigan has found frequent co-colonization of vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) among patients in nursing facilities.

In the prospective cohort study, published yesterday in the American Journal of Infection Control, researchers analyzed microbial culture data from newly admitted patients at six nursing facilities in southeast Michigan from November 2013 through November 2015. They wanted to investigate the epidemiology of VRE and MRSA co-colonization because of concerns that MRSA can acquire the vancomycin-resistance gene vanA and develop resistance to vancomycin, which further limits treatment options.

The cultures were obtained from various anatomic sites and from open wounds and indwelling device insertion sites to determine colonization status, and demography, comorbidity, and antimicrobial use data were collected to determine factors predictive of co-colonization.

In total, 508 patients were enrolled in the study, with an average length of stay of 28.5 days. Overall prevalence of MRSA and VRE co-colonization in the patients was 8.7%, 8.9% for MRSA alone, and 23.4% for VRE alone—a number the authors note is significantly higher than previously-reported VRE prevalence estimates in post-acute care facilities (5% to 18%). Multivariate analysis found that indwelling device use (odds ratio [OR], 5.5; 95% confidence interval [CI], 2.2 to 13.7), antibiotic use (OR, 2.5; 95% CI 1.4 to 4.2), diabetes (OR, 1.9; 95% CI, 1.0 to 3.8), and open wounds (OR, 1.9; 95% CI, 1.0 to 3.6) were independent predictors of co-colonization.

"Co-colonization with MRSA and VRE was frequent and perhaps driven by a high prevalence of VRE in our study population," the authors write. They conclude that future studies are needed to investigate the role VRE transmission, the presence of wounds, and targeted screening and prevention measures play in patient co-colonization.

Nov 27 Am J Infect Control study





Study: UV disinfection tied to lower C diff levels in high-burden units

Adding ultraviolet (UV) disinfection to terminal cleaning protocols was tied to reduced Clostridioides difficileinfection rates, researchers from the Mayo Clinic reported yesterday in the American Journal of Infection Control.

C diff spores are known to resist standard cleaning, and hospitals are exploring other methods to cut contamination levels. The study took place in hospital wards that have high C diff burden, including hematology and bone marrow transplant units and a medical-surgical unit. Bleach cleaning was already being used on the wards to reduce C diff levels, but infection rates still remained high.

Researchers used the UV intervention after patient discharge and terminal cleaning in three units and used three similar units as controls. At baseline, C diff infection rates were similar for both groups of units.

Intervention rooms got pulsed xenon UV disinfection for a 6-month period between October 2014 and March 2015. Disinfection was performed in three positions in 5-minute cycles after terminal cleaning and before the bed was made. Drawers and doors inside the room were left open, phone and blood pressure cuffs were hung, television remotes were on the tray table, pillows were on the window ledges, and curtains were positioned to allow the grip to be disinfected. One of the three cycles was completed in the bathroom.

After 6 months, the C diff infection rate in the intervention rooms decreased to 11.2 per 10,000 patient days, compared to 28.7 per 10,000 patient days in the control rooms. Also, researchers found a reduction in vancomycin-resistant enterococci (VRE) acquisition in units that got UV disinfection.

The team noted that the study was the first direct head-to-head comparison in the same hospital using UV disinfection in addition to bleach.

They said based on the results, the hospital continued UV disinfection in more units with high C diff burden and the devices have been well received by staff, patients, and families. However, they noted that the pulsed light was an annoyance to staff and other patients in intensive care units with glass doors. UV disinfection added about 25 minutes to room processing time, they said.

Though UV devices were expensive and incur additional costs for training, high C diff infection rates can also take a high financial toll, the group wrote. UV disinfection could be a cost-saving measure, depending on baseline C diff infection rates and performance on other healthcare-associated infection measures, they added.

Nov 27 Am J Infect Control abstract

