For MRSA Prevention, Clean Surfaces as Well as Hands

GLASGOW, Scotland, Oct. 31 -- Focusing more attention on cleaning door handles and other frequently-touched surfaces in hospitals may reduce transmission of methicillin-resistant Staphylococcus aureus (MRSA) beyond what can be accomplished by hand washing alone.
So reported Stephanie J. Dancer, M.D., of Southern General Hospital here, in a review published online in The Lancet Infectious Diseases.
Although clean hands are important, "introduction of additional cleaning services is easier than improvements in hand-hygiene compliance," she wrote.
The review came on the heels of increasing attention to MRSA in the media after outbreaks at Connecticut high schools and the death of a student in Virginia. (See: Survey Report: MRSA Publicity Will Make a Difference and Focus on Community-Acquired MRSA Was Preceded by Cadence of Concerns)
The focus was also turned on MRSA in the field of infectious diseases following a report earlier this month from the CDC that invasive MRSA was three times more common than previously estimated. (See: Invasive MRSA More Pervasive Than Suspected)
Despite all the attention, though, the importance of hospital cleaning is still debated, Dr. Dancer said.
"There is little direct evidence for the effectiveness of cleaning because it has never been afforded scientific status," she wrote.
Cleanliness of hospitals is usually assessed visually and is defined in cleaning manuals, monitoring strategies, and infection control guidelines, but dirt does not necessarily correlate with growth of MRSA or other pathogens, Dr. Dancer said.
One study, she noted, found that 82% to 91% of hospital wards were visibly clean but only 30% to 45% were considered microbiologically clean and just 10% to 24% were free from organic soil. Another study failed to correlate British hospital hygiene performance scores to MRSA rates.
The staphylococcal transmission cycle between people and their environment show that the disease is remarkably resilient and can be found on virtually all surfaces in hospitals, Dr. Dancer said.
Staphylococci bacteria can be found in the air and environment in which colonized patients live or through which they pass. There is "overwhelming" evidence, she said, for MRSA contamination on virtually all hospital surfaces, including door handles, television sets, beds, and paper.
On average, Dr. Dancer said, MRSA is found on about one-third of hospital surfaces sampled regardless of whether sampling occurred during an outbreak situation.
"The fact that most of these items can be touched by hands is important when considering the origin of MRSA contamination," she noted.
Infected patients most frequently carry the bacteria in their nose.
"Given the propensity for people to pick, touch, or blow their noses, it is not surprising that carriers will often harbor their own strain of S. aureus on their fingers, which they will then transfer to any site accessible to their hands," Dr. Dancer wrote.
But transmission is not limited to habitual carriers, because anyone who has just touched a contaminated site can contribute to the spread of bacteria as well, the researcher said.
Even if fingertips transport only a few colony-forming units of MRSA, as few as 10 could cause an infection.
All cleaning methods -- routine vacuuming and detergent-based cleaning, disinfectant-based deep cleaning, and decontamination with gaseous hydrogen peroxide -- have been shown to reduce MRSA in the hospital environment. Cutting down on the number of microbes present should reduce the risk of infection, Dr. Dancer said.
But, liquid disinfectants and detergents would damage the many types of electronic equipment, "providing more hand-touch sites that require a greater degree of sophisticated cleaning attention," she wrote.
Furthermore, MRSA risk lingers even at hospitals that exceeded CDC and Healthcare Infection Control Practices Advisory Committee standards for room cleaning procedures at discharge. (See: MRSA Risk Lingers from ICU Room's Prior Occupant)
And, the expense of extra cleaning can be prohibitive, especially in view of the current preoccupation with hospital budgets, she said.
Concentrating already available cleaning resources on high-risk hand-touch sites may be the most cost-effective cleaning strategy other than campaigning for more cleaning hours, she concluded.
"There can be no doubt that prioritizing hand hygiene is the single most beneficial intervention in the control of MRSA and many other pathogens," she said.
However, hand-hygiene initiatives have been less successful than environmental cleaning in some studies.
"And even if everyone does wash their hands properly, the effects of exemplary hand hygiene are eroded if the environment is heavily contaminated with MRSA," Dr. Dancer added.
Dr. Dancer reported no conflicts of interest.Primary source: The Lancet Infectious DiseasesSource reference: Dancer SJ, et al "Importance of the environment in methicillin-resistant Staphylococcus aureus acquisition: the case for hospital cleaning" Lancet Infect Dis 2007; DOI: 10.1016/S1473-3099(07)70241-4.