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Disinfection of iPad to reduce contamination with Clostridium difficile and methicillin-resistant Staphylococcus aureus

      To the Editor:
      In recent years, there has been an accelerated use of electronic medical records resulting in a more efficient management of patient information.
      • Erstad T.L.
      Analyzing computer based patient records: a review of literature.
      • Delpierre C.
      • Cuzin L.
      • Fillaux J.
      • Alvarez M.
      • Massip P.
      • Lang T.
      A systematic review of computer-based patient record systems and quality of care: more randomized clinical trials or a broader approach?.
      Consequently, mobile technology devices including computer tablets such as iPad (Apple, Cupertino, CA) have been increasingly used to access information for patient care.
      • Patel B.K.
      • Chapman C.G.
      • Luo N.
      • Woodruff J.N.
      • Arora V.M.
      Impact of mobile tablet computers on internal medicine resident efficiency.
      This observed trend raises questions on infection control measures to avoid transmission of pathogens through this new technology. The manufacturer recommends cleaning the device using a slightly damp, lint-free cloth.

      How to Clean Apple Products. Apple Inc Web site. Available from: http://support.apple.com/kb/HT3226. Published 2011. Accessed September 2012.

      We conducted a point prevalence survey to assess contamination of hospital iPads and evaluated methods to reduce contamination with Clostridium difficile and methicillin-resistant Staphylococcus aureus (MRSA).
      Twenty hospital provided iPads were sampled by swabbing the screen, plating onto C difficile selective agar, and then incubating anaerobically. A separate swab was plated on blood agar and incubated in room air. Colonies with unique morphology were subjected to identification and susceptibility testing in accordance with Clinical Laboratories Standards Institute guidelines.
      Clinical Laboratories Standards Institute
      Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically; Approved Standard–seventh edition. Clinical and Laboratory Standards Institute document M7-A7 [ISBN 1-56238-587-9].
      We then assessed the proportion of devices contaminated with C difficile, S aureus, and gram-negative microorganisms.
      We also evaluated disinfection techniques of iPads by inoculating 10-μL aliquots of approximately 1.5 × 104 colony-forming units (CFU) of MRSA onto a bleach precleaned screen surface that was allowed to air-dry. The surface was wiped with 70% isopropyl alcohol pads (Medline Industries, Mundelein, IL), 0.6% hypochlorite bleach wipes (PDI Inc, Orangeburg, NY), or a 2 × 2-inch soft, lint-free microfiber lens cloth moistened with sterile water. The screen was then swabbed and plated on MRSA selective agar. The numbers of colonies were counted, and 10 replicates were done for each cleaning material. The experiment was repeated using approximately 1.5 × 104 spores of C difficile instead of MRSA. Data were collected for each cleaning agent, and control plates were used to ensure conditions for growth.
      Of 20 iPads evaluated by culture, 3 (15%) grew S aureus. There was neither growth of C difficile cultures nor any gram-negative pathogens. Figure 1 shows results of the proportion of C difficile and MRSA recovered from iPad after inoculation followed by decontamination with different methods. These data clearly show that bleach wipes were able to remove the inoculated spores completely. The microfiber cloth was significantly more effective than alcohol wipes in removing C difficile spores from the screen surface (P < .001). There was only a mean of 0.93-log10 CFU left after wiping with moistened cloth versus 2.3-log10 CFU remaining after using the alcohol wipes. For iPads inoculated with MRSA, alcohol wipes, bleach, and moistened cloth each removed 100% of the pathogen.
      Figure thumbnail gr1
      Fig 1Effect of different agents on decontamination of iPad.
      To our knowledge, this study is the first to assess the potential infection control implications of iPads and evaluate different methods for removing MRSA and C difficile. A total of 15% (3 out of 20) of iPads was contaminated with S aureus. The low rate of contamination in this study could possibly be due to the overall low incidence of resistant organisms in our facility, as well as other infection control measures including monitoring of housekeeping cleaning, an established antimicrobial stewardship program, and compliance with hand hygiene.
      There are no existing guidelines specific for iPads in relation to infection control. Apple recommends the use of a soft, slightly damp, lint-free cloth and that care must be observed to avoid exposing moisture in any openings. They do not recommend using chemicals or abrasives to clean the device. The unit has an oleophobic coating on the screen that allows it to repel oil or moisture.

      How to Clean Apple Products. Apple Inc Web site. Available from: http://support.apple.com/kb/HT3226. Published 2011. Accessed September 2012.

      We found that microfiber cloth is effective in removing MRSA. However, it will only reduce and not completely eliminate C difficile. This was only achieved by a sporocidal agent. The significant effectiveness of moistened cloth compared with the alcohol wipes suggests that, possibly, direct contact with friction alone is sufficient to remove a majority of spores. Similar findings were observed in the better decontamination efficacy of microfiber clothes compared with other materials as well as in the removal of C difficile spores from hands with soap and water as compared with alcohol-based hand rubs.
      • Diab-Elschahawi M.
      • Assadian O.
      • Blacky A.
      • Stadler M.
      • Pernicka E.
      • Berger J.
      • et al.
      Evaluation of the decontamination efficacy of new and reprocessed microfiber cleaning cloth compared with other commonly used cleaning cloths in the hospital.
      • Jabbar U.
      • Leischner L.
      • Kasper D.
      • Gerber R.
      • Sambol S.P.
      • Parada J.P.
      • et al.
      Effectiveness of alcohol-based hand rubs for removal of Clostridium difficile spores from hands.
      Given the limitation of the damp cloth to eliminate all pathogens, especially C difficile, nonporous cases or covers for iPads and screen protectors may allow the use of disinfecting agents without directly exposing the device. There should also be emphasis on hand hygiene. We recommend avoiding iPad use in rooms on contact precautions. Our institution has provided white coats sewn with large-sized pockets (that we call iPockets) to accommodate the iPads and decrease the environmental contact of the tablets.
      Our study has possible limitations. Our sample size is modest, and the study was conducted in a single medical center with a low incidence of infections with MRSA (0.18/1,000 patient-days) and C difficile (4.45/10,000 patient-days). We focused only on the iPad screen, although the whole unit including accessories has the potential for contamination. Physical effects of the cleaning agents on the device were also not considered.
      In summary, contamination with pathogens such as S aureus occurs in iPads used for patient care. Current recommended cleaning procedures for the device are effective in removing MRSA but do not address pathogens such as C difficile. Further studies and definite guidelines are needed because we see its increased use in the health care setting.

      References

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        Analyzing computer based patient records: a review of literature.
        J Healthc Inf Manag. 2003; 17: 51-57
        • Delpierre C.
        • Cuzin L.
        • Fillaux J.
        • Alvarez M.
        • Massip P.
        • Lang T.
        A systematic review of computer-based patient record systems and quality of care: more randomized clinical trials or a broader approach?.
        Int J Qual Health Care. 2004; 16: 407-416
        • Patel B.K.
        • Chapman C.G.
        • Luo N.
        • Woodruff J.N.
        • Arora V.M.
        Impact of mobile tablet computers on internal medicine resident efficiency.
        Arch Intern Med. 2012; 172: 436-438
      1. How to Clean Apple Products. Apple Inc Web site. Available from: http://support.apple.com/kb/HT3226. Published 2011. Accessed September 2012.

        • Clinical Laboratories Standards Institute
        Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically; Approved Standard–seventh edition. Clinical and Laboratory Standards Institute document M7-A7 [ISBN 1-56238-587-9].
        Clinical and Laboratory Standards Institute, Wayne [PA]2006
        • Diab-Elschahawi M.
        • Assadian O.
        • Blacky A.
        • Stadler M.
        • Pernicka E.
        • Berger J.
        • et al.
        Evaluation of the decontamination efficacy of new and reprocessed microfiber cleaning cloth compared with other commonly used cleaning cloths in the hospital.
        Am J Infect Control. 2010; 38: 289-292
        • Jabbar U.
        • Leischner L.
        • Kasper D.
        • Gerber R.
        • Sambol S.P.
        • Parada J.P.
        • et al.
        Effectiveness of alcohol-based hand rubs for removal of Clostridium difficile spores from hands.
        Infect Control Hosp Epidemiol. 2010; 31: 565-570