Evaluation of an ultraviolet room disinfection protocol to decrease nursing home microbial burden, infection and hospitalization rates

Christine R. Kovach1*, Yavuz Taneli2, Tammy Neiman1, Elaine M. Dyer3, Alvin Jason A. Arzaga3 and Sheryl T Kelber1

Abstract

Background: The focus of nursing home infection control procedures has been on decreasing transmission between healthcare workers and residents. Less evidence is available regarding whether decontamination of high-touch environmental surfaces impacts infection rates or resident outcomes. The purpose of this study was to examine if ultraviolet disinfection is associated with changes in: 1) microbial counts and adenosine triphosphate counts on hightouch surfaces; and 2) facility wide nursing home acquired infection rates, and infection-related hospitalization.

Methods: The study was conducted in one 160-bed long-term care facility. Following discharge of each resident, their room was cleaned and then disinfected using a newly acquired ultraviolet light disinfection device. Shared living spaces received weekly ultraviolet light disinfection. Thirty-six months of pretest infection and hospitalization data were compared with 12 months of posttest data. Pre and posttest cultures were taken from high-touch surfaces, and luminometer readings of adenosine triphosphate were done. Nursing home acquired infection rates were analyzed relative to hospital acquired infection rates using analysis of variance procedures. Wilcoxon signed rank tests, The Cochran’s Q, and Chi Square were also used.

Results: There were statistically significant decreases in adenosine triphosphate readings on all high-touch surfaces after cleaning and disinfection. Culture results were positive for gram-positive cocci or rods on 33% (n = 30) of the 90 surfaces swabbed at baseline. After disinfectant cleaning, 6 of 90 samples (7.1%) tested positive for a gram-positive bacilli, and after ultraviolet disinfection 4 of the 90 samples (4.4%) were positive. There were significant decreases in nursing home acquired relative to hospital-acquired infection rates for the total infections (p = .004), urinary tract infection rates (p = .014), respiratory system infection rates (p = .017) and for rates of infection of the skin and soft tissues (p = .014). Hospitalizations for infection decreased significantly, with a notable decrease in hospitalization for pneumonia (p = .006).

Conclusions: This study provides evidence that the pulsed-xenon ultraviolet disinfection device is superior to manual cleaning alone for decreasing microbes on environmental surfaces, as well as decreasing infection rates, and the rates of hospitalization for infection. Results suggest that placing a stronger emphasis on environmental surface disinfection in long-term care facilities may decrease nursing home acquired infections.

Keywords: Nursing home, Long-term care, Infection, Pneumonia, Prevention, Environment

Abstract

Background
Ultraviolet lighting is an alternative to laminar airflow in the operating room that may be as effective for lowering the number of environmental bacteria and possibly lowering infection rates by killing the bacteria rather than simply reducing the number at the operative site. The purpose of the present study was to compare the infection rates following joint replacement procedures performed by one orthopaedic surgeon with and without the use of ultraviolet lighting.

Methods
From July 1986 to July 2005, one surgeon performed 5980 total joint replacements at one facility. In September 1991, ultraviolet lighting was installed in the operating rooms. All procedures that were performed before the installation of the ultraviolet lighting utilized horizontal laminar airflow, whereas all procedures that were performed after that date utilized ultraviolet lighting without laminar airflow. Factors associated with the rate of infection were analyzed.

Results
Over a nineteen-year period, forty-seven infections occurred following 5980 joint replacements. The infection rate without ultraviolet lighting (and with laminar airflow) was 1.77%, and the infection rate with ultraviolet lighting was 0.57% (p < 0.0001). The odds of infection were 3.1 times greater for procedures performed without ultraviolet lighting (and with laminar airflow) as compared with those performed with only ultraviolet lighting (p < 0.0001). The infection rate associated with total hip replacement decreased from 1.03% to 0.72% (p = 0.5407), and the infection rate associated with total knee replacement decreased from 2.20% to 0.50% (p < 0.0001). Revision surgery, previous infection, age, total body mass index, use of cement, disease, and diagnosis were not associated with an elevated infection rate.

Conclusion
When appropriate safety precautions are taken, ultraviolet lighting appears to be an effective way to lower the risk of infection in the operating room during total joint replacement surgery.

Level of Evidence
Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence.