Bacterial Contamination of Keyboards: Efficacy and Functional Impact of Disinfectants

William A. Rutala, PhD, MPH; Matthew S. White, PhD, MPH; Maria F. Gergen, MT(ASCP); David J. Weber, MD, MPH

Background.Computers are ubiquitous in the healthcare setting and have been shown to be contaminated with potentially pathogenic microorganisms. This study was performed to determine the degree of microbial contamination, the efficacy of different disinfectants, and the cosmetic and functional effects of the disinfectants on the computer keyboards.


Methods.We assessed the effectiveness of 6 different disinfectants (1 each containing chlorine, alcohol, or phenol and 3 containing quaternary ammonium) against 3 test organisms (oxacillin‐resistant Staphylococcus aureus [ORSA], Pseudomonas aeruginosa, and vancomycin‐resistant Enterococcus species) inoculated onto study computer keyboards. We also assessed the computer keyboards for functional and cosmetic damage after disinfectant use.


Results.Potential pathogens cultured from more than 50% of the computers included coagulase‐negative staphylococci (100% of keyboards), diphtheroids (80%), Micrococcus species (72%), and Bacillus species (64%). Other pathogens cultured included ORSA (4% of keyboards), OSSA (4%), vancomycin‐susceptible Enterococcus species (12%), and nonfermentative gram‐negative rods (36%). All disinfectants, as well as the sterile water control, were effective at removing or inactivating more than 95% of the test bacteria. No functional or cosmetic damage to the computer keyboards was observed after 300 disinfection cycles.


Conclusions.Our data suggest that microbial contamination of keyboards is prevalent and that keyboards may be successfully decontaminated with disinfectants. Keyboards should be disinfected daily or when visibly soiled or if they become contaminated with blood.




Dr. Rutala and Weber and Ms. Gergen are from the Department of Hospital Epidemiology, University of North Carolina Health Care System, Chapel Hill, North Carolina. Drs. Rutala and Weber and Mr. White are from the Division of Infectious Diseases, University of North Carolina School of Medicine, Chapel Hill, North Carolina.


© 2006 by The Society for Healthcare Epidemiology of America. All rights reserved.


Dr. Bill Rutala is a professor at the University of North Carolina’s (UNC) Division of Infectious Diseases Department of Medicine. He also is the director of UNC’s Hospital Epidemiology, Occupational Health and Safety Program; director and co-founder of UNC School of Medicine’s Statewide Program for Infection Control and Epidemiology; advisor to the Centers for Disease Control and Prevention, the Food and Drug Administration, the U.S. Environmental Protection Agency and the Federal Trade Commission; and a retired colonel with the U.S. Army Reserve. Dr. Rutala serves on the editorial board of Infection Control and Hospital Epidemiology. He also is published in the fields of infectious diseases, infection control, disinfection, sterilization and medical waste and has authored several guidelines, including “CDC Guideline for Disinfection and Sterilization in Healthcare Facilities.” Dr. Rutala earned his BS degree in science from Rutgers University, MS degree in microbiology from the University of Tennessee and a MS in public health and a Ph.D. in microbiology from UNC’s School of Public Health.





Bacterial Contamination of Keyboards: Efficacy and Functional Impact of Disinfectants:  Created on April 1st, 2010.  Last Modified on May 14th, 2010


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