Bacterial Contamination on Smartphones Owned by HealthCare Workers

Smartphones owned by healthcare workers (HCW) are often contaminated with bacteria; however, it is the posterior surface rather than the touchscreen that may have significantly more contamination, according to findings published in BMC Infectious Diseases.

Results of previous studies have found that mobile phones and smartphones owned by HCWs are often contaminated with bacteria, the prevalence of which ranges from 10% to 100%. Studies that assess microbial contamination on smartphone surfaces often target the touchscreen portion of smartphones. Because they are often covered or encased, the posterior surfaces are less frequently cleaned and not considered “high-touch” areas.

A team of investigators in Japan conducted a cross-sectional study to compare the prevalence of microbial contamination found on the touchscreen with that found on the posterior surface of smartphones owned by HCWs. Bacteria found on each surface of participants’ smartphones were isolated separately. The primary study outcome was the prevalence of microbial contamination on each surface of the smartphones, as well as the associated bacterial species.

A total of 84 participants (mean age, 31 years; 63.1% women) with smartphones were included in the study. Of the cohort, 19 were physicians, 49 were nurses, and 9 were rehabilitation therapists. The remaining participants were either assistants, clerks, or pharmacists.

The participants owned their current smartphones for a median of 18 months; 66 participants (78.6%) had a protective film on the touchscreen, and 69 participants (82.1%) had a cover on the posterior surface. In addition, 23 participants (27.4%) noted that they used their smartphone at the patient bedside. Only 9 participants (10.7%) claimed to regularly sanitize their smartphones, but 70 participants (83.3%) recognized that mobile phones collect bacteria and may increase the risk for nosocomial infections.

Of the 84 devices analyzed, 49 (58.3%) were found to be contaminated with bacteria; 27 (32.1%) had contaminated touchscreens, 39 (46.6%) had contaminated posterior surfaces, and 17 (20.2%) had contamination on both the touchscreen and posterior surface. There was an increased frequency of contamination on the posterior surface compared with the touchscreen (P =.041).

Of the 27 smartphones with contaminated touchscreens, cultures were obtained and grew a median of 2 colonies of bacteria. The most frequently cultured bacteria were coagulase-negative staphylococci (13 smartphones) and Bacillus species (13 smartphones). The frequency of touchscreen contamination was not related to the use of a protective film, sex of the smartphone owner, regular disinfection, or handwashing before smartphone use.

Cultures obtained from the 39 smartphones with contaminated posterior surfaces also grew a median of 2 colonies of bacteria. The most frequently cultured bacteria were Bacillus species (26 smartphones) and coagulase-negative staphylococci (22 smartphones). Similar to the touchscreen assessment, no significant differences in the frequency of posterior surface contamination were related to the use of a posterior surface covering, sex of the smartphone owner, regular disinfection, or handwashing before smartphone use.

“Although the posterior surface is not as frequently touched as the touchscreen, it could be a fomite of transmitting bacteria to the healthcare environment once contaminated. Thus, we recommend that the posterior surface of smartphones be cleaned, similar to the touchscreen, in order to avoid cross-contamination of healthcare settings, particularly [intensive care unit] settings,” the authors noted.

The investigators recommended the routine cleaning of touchscreen and posterior surfaces of smartphones for the prevention of bacterial dissemination in the healthcare environment.

“However, it is unclear how often the posterior surface of smartphones needs to be cleaned, for which further studies are awaited,” the researchers added.

Reference

Kuriyama A, Fujii H, Hotta A, Asanuma R, Irie H. Prevalence of bacterial contamination of touchscreens and posterior surfaces of smartphones owned by healthcare workers: a cross-sectional study. BMC Infect Dis. 2021;21(1):681. doi:10.1186/s12879-021-06379-y