Bacteria on the Keyboard

There are more germs on some computer keyboards than on the toilet seat at home. And it’s not just a matter of harmless pathogens. Regular cleaning of the computer keyboard and mouse is therefore strongly recommended. The British consumer magazine “Which?” put this to the test at the beginning of 2008 and came up with some shocking results.

Keyboard hazardous to health?

Some computer keyboards were found to be more contaminated with bacteria than a toilet seat, which was also examined, and were thus potentially a serious health hazard. Eating at the PC, dust particles and not washing hands after using the toilet are thought to be the main contributors to a bacteria biotope on the keyboard. The British consumer protection experts, together with a microbiologist, took a close look at more than 30 keyboards from their own office. The majority passed the hygiene test, but individual keyboards were so heavily contaminated with bacteria that their users were at risk of serious stomach upset if the pathogens entered the organism via the fingers.

Uncleaned keyboards

Four keyboards failed outright because of health hazards. Two of them had far exceeded the staphylococcus warning level, and another keyboard had 150 times as many germs as allowed. This keyboard was five times as bacteria-infested as a toilet seat that was also examined, and was at increased risk for food poisoning, stomach upset or diarrhea. Meals eaten directly at the desk above the keyboard are considered the largest source of dirt and bacteria in keyboards. The leftover food encourages the growth of germs, according to the magazine.

Potential health hazard

A random test by the WDR television consumer magazine “Markt” (broadcast on March 31, 2008) had also previously been made and found that PC keyboards can be true breeding grounds for bacteria. Especially where many people use a keyboard, for example in schools, offices or Internet cafés, pathogens could spread via them, according to the consumer protection experts. Together with Professor Hans-Jürgen Tietz of the Institute for Fungal Diseases (Berlin), they examined 20 keyboard samples from Internet cafés and offices. Result: 18 of it were loaded. Puddle germs were found, which are resistant to many disinfectants and can trigger infections; fecal bacteria, many of which are known pathogens in humans (e.g. Escherichia coli); pus bacteria (e.g. Staphylococcus aureus), which can lead to skin infections (boils) in humans, and in one case also a nail fungus. Despite their findings, however, the TV magazine “Markt” and Professor Tietz gave the all-clear in principle: as long as only healthy people work at the PCs, they will generally not become ill as a result of these germs. But they are germ carriers and potential germ carriers. For sick, weakened or susceptible people, this could then become a problem. They should better not come into contact with the germs.

Danger from keyboards in hospitals

For years, computers have made their way into hospitals, for example for documentation – and with them potential dangers, especially for sick people. Germs often cavort in the cracks of the keyboard, which in turn can be transmitted by the hands of the staff. This can be particularly fatal in intensive care units, where patients are often seriously ill and therefore have weakened immune systems. In addition, various cannulas, probes and catheters offer germs easy access routes into the body. For example, American scientists showed that more microorganisms sometimes dwell on the keyboard than on other objects in the patient’s room and that multidrug-resistant germs can survive there for more than 24 hours.

Cleaning the keyboard – this is how!

For basic cleaning of a keyboard (and mouse) a damp cloth soaked in alcohol (or glass cleaner!) is suitable, against fungi only a good disinfectant helps. In the specialized trade, various cleaning utensils can be purchased, also there are now special hygiene keyboards with a germ-killing, antibacterial surface coating. Sources:

  • Bures S, Fishbain JT, Uyehara CF, Parker JM, Berg BW. Computer keyboards and faucet handles as reservoirs of nosocomial pathogens in the intensive care unit. Am.J.Infect.Control 2000; 28: 465-71.
  • Devine J, Cooke RP, Wright EP.Ist die Kontamination von stationären Computerterminals mit Methicillin-resistenten Staphylococcus aureus (MRSA) ein Surrogatmarker für die nosokomiale MRSA-Übertragung und die Compliance beim Händewaschen? J.Hosp.Infect. 2001; 48: 72-5
  • Neely AN, Maley MP. Der Umgang mit kontaminierten Computertastaturen und das mikrobielle Überleben. Am.J.Infect.Control 2001; 29: 131-2
  • Noskin, G. A. Hospital computer keysboards and keyboard covers harbor potentially harmful bacteria. Hosp.Health Netw. 2005; 79[5], 81-82