April 26, 2006 -- You might want to add "clean the computer keyboard" to your daily chores, based on a new study.
The study, published in Infection Control and Hospital Epidemiology, comes from William Rutala, PhD, MPH, and colleagues at the University of North Carolina (UNC) at Chapel Hill.
Rutala's team tested 25 computer keyboards from UNC's Health Care System for bacteria. The researchers also placed bacteria on several laptop computers and tried to remove those bacteria with various disinfectants.
The bottom line: The keyboards were home to several sorts of bacteria, and cleaning helped.
"Our data suggest that microbial contamination of keyboards is prevalent and that keyboards may be successfully decontaminated with disinfectants," the researchers write.
What's on That Keyboard?
The researchers tested 25 computer keyboards from UNC's burn intensive care unit, cardiothoracic intensive care unit, and six nursing units housing patients receiving short-term care.
Rutala's team found two or more microorganisms on all of the computer keyboards. For instance, all of those keyboards tested positive for a type of staph bacterium (coagulase-negative staphylococci), which is one of the most common causes of bloodstream infections in hospitalized patients. Diphtheroids were found on 80% of the keyboards. CancerCancer, AIDS, and other patients in the hospital whose immune system is weak are at high risk for infections from diphtheroids.
Remember, those keyboards came from a hospital. Your home or office might not have the same set of bacteria. However, another study released in February by other researchers showed various bacteria in the workspaces of teachers, accountants, bankers, and other professionals.
Cleaning the Keyboard
Rutala and colleagues loaded certain keys on laptop computers with several sorts of bacteria (Pseudomonas aeruginosa, Staphylococcus aureus, and vancomycin-resistant enterococcus).
After 45 minutes, the researchers used various disinfectants to try to delete those bacteria from the keyboards.
The cleaners included paper towels dampened with sterile water, alcohol, or chlorine. The researchers also tested disinfecting wipes made by companies including Clorox and Metrex.
Rutala has consulted for both Clorox and Metrex. Another researcher who worked on the study has consulted for Clorox, the journal notes.
"All disinfectants, as well as the sterile water control, were effective at removing or inactivating more than 95% of the test bacteria," the researchers write. The three commercially packaged wipes were all effective for 48 hours, but the paper towels moistened with alcohol or sterile water didn't show long-term effectiveness, the researchers report.
Hospital computers' keyboards "should be disinfected daily or when visibly soiled or if they become contaminated with blood," write Rutala and colleagues.
Their study doesn't include cleaning recommendations for computers not used in hospitals. But in a news release, Rutala notes that people may want to clean a computer's keyboard with a disinfecting wipe before someone else uses that keyboard.
"This might help prevent the spread of infection during cold and fluflu season," Rutala says in the news release.
The keyboards used in Rutala's study went through 300 cleaning cycles and showed no damage, note Rutala and colleagues. Of course, if you choose to clean your computer, follow the manufacturer's instructions.