Keypad Mobile Phones are Associated with a Significant Increased Risk of Microbial Contamination Compared to Touch Screen Phones

The use of mobile phones in the clinical environment by healthcare workers has become widespread. Despite evidence that these devices can harbour pathogenic micro-organisms there is little guidance on how to reduce contamination.

Recently touch screen phones with a single flat surface have been introduced. We hypothesise that bacterial contamination of phones used in hospitals will be lower on touch screen devices compared to keypad devices.

Sixty seven mobile phones belonging to health care workers were sampled. The median colony count for touch screen phones and keypad devices was 0·09 colony forming units (cfu)/cm² (interquartile range (IQR) 0.05–0·14) and 0·77 cfu/cm² (IQR range 0·45–3.52) respectively.

Colony counts were significantly higher on the keypad phones (Fisher’s exact test p<0.001).  Multivariate analysis showed the type of phone (keypad vs. touch screen) was associated with increased colony counts (F-statistic 14.13: p<0.001).

Overall, nine (13%) phones grew either meticillin resistant Staphylococcus aureus or vancomycin resistant enterococci. Eight (24%) keypad phones were contaminated with these organisms compared with one touch screen phone (3%).

Our data indicate that touch screen mobile phones are less contaminated than their keypad counterparts, and they are less likely to harbour pathogenic bacteria in the clinical setting.