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Which? report : How to clean your PC | 01 May 2008

Bacteria in your PC

Our study reveals shocking levels of bacteria on computer parts.

 

cleaning your pc keyboard

A microbiologist swabbed our keyboards

Our study

We bravely turned the microscope on our own keyboards commissioning a microbiologist to swab over 30 keyboards within our London office. The shocking results revealed that some of these keyboards were harbouring harmful bacteria that could potentially give their users a serious stomach upset.

Most of the keyboards and the toilet door handle passed our hygiene test but four keyboards were potential health hazards. Two had staphylococcus aureus at ‘warning’ levels, putting the users at risk of illness if the bacteria grew further.

Worse case scenario

In one case, microbiologist James Francis (from Kingmoor Technical Services) recommended the removal of one our keyboards as a precautionary step. This had 150 times the pass limit of bacteria, and was five times filthier than the toilet seat swabbed.

The germs on this keyboard could cause food poisoning symptoms such as diarrhoea and other stomach upsets at the levels that we discovered.

James, who has 22 years experience studying bacteria, commented: ‘That keyboard is increasing the risk of its user becoming ill. I haven’t seen a reading like that in a very long time. It was off the scale.’ Microbiologist Dr Mark Enright of Imperial College London agrees: ‘You shouldn’t have gut bacteria on a keyboard.’

Bugs under the microscope

Our microbiologist was looking for these bugs which indicate poor hygiene: 

Enterobacteriaceae

Enterobacteriaceae doesn't belong on a keyboard

Enterobacteriaceae 

This group of bacteria lives in the stomachs of humans and animals.

Coliform

Found in earth, air and soil, this group of bugs are associated with faecal matter. 

Escherichia Coli (E Coli)

These are in the coliform group and are predominantly from faecal origin and a very good indicator of poor hygiene. 

Staphylococcus

Staphylococcus Aureus can make keyboard users ill

Staphylococcus Aureus 

Found on human skin and can cause illnesses like skin infections and food poisoning if it enters the body.

Where does the bacteria come from?

The main cause of a bug-infested keyboard is eating lunch at your desk. The food deposits encourage the growth of millions of bacteria, which can lead to stomach bugs.

Poor personal hygiene such as dodging the hand washing basin after going to the toilet is also to blame.

Our two keyboards that failed the hygiene test have been replaced. But as James says, the best way to get rid of bacteria is to stop it getting there, which means not eating at your keyboard and washing your hands after going to the loo.

Dust is also a major problem because it traps moisture – exactly what bacteria need cause to flourish.

How clean is your keyboard?

We asked over 4,000 Which? online panel members how often they clean PC components (survey conducted in January and February 2008), with results varying dramatically, showing plenty of opportunity for bugs to thrive.

  • 11% of respondents said that they never clean their keyboard 
  • 20% admitted to never cleaning their mouse while 19% give their mouse a monthly clean
  • 27% clean their monitor monthly
  • 25% of respondents with a laptop cleaned it monthly and 13% of respondents said that they never cleaned it
How frequently do you clean your keyboard?
Cleaning frequencyPercentage of people
Less than once a month46% 46%
More than once a month29% 29%
Once a month22% 22%
Don't know2% 2%
Table notes
Sample: 3,975 Figures rounded so don’t add up to 100 per cent