Infection Control and the Computer

They are everywhere. They sit on every bench, on every office desk and on mobile surfaces. Usually accompanied by a mouse, they are the computer keyboards many of us use all day long to input and retrieve information to treat our patients. They are also a clear source of contamination that is often overlooked when considering infection control issues in the laboratory.

Dirty as Toilets
A 2008 British study compared bacteria on bathroom door handles, toilets and office keyboards. Keyboards were found to harbor up to five times as much bacteria as toilet seats. Poor personal hygiene and eating lunch over the keyboard were cited reasons, but a user survey also suggests that most users don’t clean keyboards religiously.1 Keyboard cultures grew enterobacteriaceae and staphylococcus, labeling the potential infections “qwerty tummy” after the first six letters on the top row of letters on a keyboard.2

The toilet analogy is closer to home than one might think. According to a 2007 study in the CDC Morbidity and Mortality Report, a computer mouse and keyboard in a first grade classroom tested positive for norovirus that linked computer technology to an outbreak in a Washington, D.C. elementary school.3 Users who don’t wash hands properly after using the toilet can contaminate keyboards with norovirus and other infectious agents.

Hopefully, healthcare professionals practice better hand hygiene than dining office workers or school-age children. Indeed, one study at Henry Ford Hospital in Detroit found more contamination in non-treatment areas. Seventy two keyboards were swabbed on two different days, six days apart. Cultures grew nine different bacteria on ten keyboards. Non-treatment areas (e.g. patient registration) showed three and a half times as much contamination as treatment areas.4

Even so, treatment areas are at risk of contaminating keyboards with multidrug resistant organisms. A 2000 study in one ICU cultured methicillin-resistant staphylococcus aureus (MRSA) from computer keyboards found to be identical to organisms infecting patients. And a 2001 study comparing two hospitals found a direct link between the number of contaminated keyboards and rates of MRSA infections. The same article states microbes tend to live longer on plastics, such as computer keys, exacerbating the problem.5

It Isn’t Just Keyboards
It isn’t just keyboards that are dirty. A mouse, trackball, or signature pad can be just as dirty. Older mice that use a rubber ball to track movement on a mousepad (called a mechanical mouse) gather dirt and are time-consuming to clean. Other laboratory input devices include barcode scanners, keypads on instruments and handheld point-of-care (POC) devices and calculators.

Even the inside of a computer can be filthy. Desktop and thin client computer cases generate heat that is dissipated by fans. These include a case fan to bring in cool air and internal fans on the motherboard, power supply and (perhaps) graphics card. Depending on the orientation of the case, dust and dirt can settle directly on one of these fans. Over time these fans circulate accumulated dirt as well as heat.

Tablets and smartphones designed to be touched could be the dirtiest of all tech. A study isolated harmful bacteria at high-risk levels on nearly twenty seven percent of tablets sampled.6 Glass touchscreens don’t work well unless fingers contain some oils — if you’ve just washed your hands, your fingertips squeak — and they don’t work at all while wearing gloves. With frequent touching while performing other tasks (including eating) they present a unique infection control challenge.

Cleaner Tech
There’s plenty you can do starting today to keep your computer hardware cleaner. Here are tips:

– While culturing hardware surfaces isn’t necessarily an indicator of qualitative risk, it can be a motivator for your staff. Begin your program by swabbing your most used surfaces: left mouse buttons, Enter and Space keys, and touch screens.

– When possible, install hardware several feet away from high risk, high splash areas such as sinks or specimen processing areas where aerosolization is probable.

– De-germ hands before and after using keyboards, mice and other tech especially in high risk clinical areas. In your outpatient areas where there is patient contact, make sure patients see you doing this.

– Invest in washable keyboards and mice in high risk areas, such as microbiology. A company called Seal Shield7 makes products that are fully immersible and that can even be placed in a dishwasher. Your group purchasing organization (GPO) may have a contract with them or a comparable vendor. For specialized keyboards, your vendor may sell a keyboard protective cover.

– Invest in a stylus for any touch screen you have. These will vary according to the type of screen: a resistive touch screen works with anything e.g. a pen cap, a surface acoustic wave screen works with a pencil eraser or other item that absorbs sound like a human finger, but a capacitive touch screen requires a special stylus that mimics the electrical conductivity of a finger.8 Capacitive styli are cheap, however.

– For other hardware, wipe down exterior surfaces along with other non-porous surfaces as part of daily maintenance using a germicidal cleaner.

– Develop a maintenance schedule to clean the inside of your hardware. This is easily done by removing the case cover and blowing out the dirt using canned air. Your IT department can help. If you’ve never done this, chances are the computer will require extensive dismantling to fully clean. (Cleaner is quieter, too!)

– Regularly clean monitor surfaces, including touch screens, following manufacturer instructions. Develop a clear policy for cleaning other surfaces, including keypads and other high-touch areas on instruments.

Tablets and smartphones are a special case within the laboratory because they are a distraction. Your hospital may forbid their use outside of break times and areas, but the same guidelines apply — including stylus use.

Finally, changing computer use can be hard, because they are everywhere and are used all the time. A direct observation with rewards program may be an effective staff motivator to change old habits. Keeping your computer surfaces clean is an important part of your infection control program and leads to better patient care.

Scott Warner is lab manager at Penobscot Valley Hospital, Lincoln, ME.


1. Keyboards harbour harmful bacteria – May – 2008 – Which? News. 2008. Available at: Accessed January 23, 2015.

2. Poulter S. How your computer keyboard is FIVE TIMES dirtier than your toilet seat – and could even give you ‘qwerty tummy’. Mail Online. 2008. Available at:–qwerty-tummy.html. Accessed January 23, 2015.

3. Childs D. Your Keyboard: Dirtier Than a Toilet. ABC News. 2008. Available at: Accessed January 23, 2015.

4. ED Computer Keyboards and Bacterial Contamination. 2010. Available at: Accessed January 23, 2015.

5. Neely A. Basic Microbiologic and Infection Control Information to Reduce the Potential Transmission of Pathogens to Patients via Computer Hardware. Journal of the American Medical Informatics Association. 2002;9(5):500-508. doi:10.1197/jamia.m1082.

6. Parris R. Find out how much bacteria is on your tablet and smartphone. Which? Conversation. 2013. Available at: Accessed February 7, 2015.

7. 100% Waterproof, spill proof, dishwasher safe keyboards, mice and TV remotes. 2015. Available at: Accessed February 7, 2015.

8. – What Stylus Do I Need?. Available at: Accessed February 7, 2015.

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