Germ Fact

Computer Keyboards as Disease Vectors

  • The average keyboard contains more than 3000 microbes per square inch, “Computers are ubiquitous in the healthcare setting and have been shown to be contaminated with potentially pathogenic microorganisms,” wrote William A. Rutala, PhD, MPH, from the University of North Carolina Health Care System in Chapel Hill in an article published in Infection Control and Hospital Epidemiology. (Infect Control Hosp Epidemiol. 2006;27:372-377) Dr. Rutala has authored several studies on the subject of contamination in hospitals.
  • In one study Dr. Rutala conducted of hospital keyboards, “More than half of the keyboards harbored coagulase-negative staphylococci (100% of keyboards), diphtheroids (80%), Micrococcus species (72%), and Bacillus species (64%). Other pathogens cultured were ORSA (4% of keyboards), oxacillin-susceptible S. aureus (4%), vancomycin-susceptible Enterococcus species (12%), and nonfermentative Gram-negative rods (36%).”
  • Food eaten near the computer provides an easy way for disease-causing molds to take hold. One type is Green Mold (Aspergillus flavus), which thrives on bread and yeasty crumbs, and can lead to lung and liver infections, liver cancer, allergies and asthma.
  • Similarly, residue from salad, fruit or cheese encourages the growth of Black Mold (Aspergillus niger), which thrives in decaying vegetable matter and stale food in general. Black Mold can cause a chronic fungal growth of the ear canal, as well as allergic aspergillosis, a hypersensitive allergic lung disease resulting from repeated inhalation of Aspergillus spores.
  • Salmonella and E. coli are readily identified as keyboard contaminants, most likely deposited there by the unwashed hands of prior users. These pathogens cause gastroenteritis, and if not treated properly, severe life-threatening illness.
  • Viruses such as Hemophilus influenza (human flu), can quickly settle on the keyboard surface after an infected coworker coughs or sneezes.
  • Resistant bacteria such as MRSA (methicillin-resistant Staphylococcus aureus) causes life-threatening infections of the skin and soft tissues, as well as necrotizing pneumonia. MRSA can stay alive on hard surfaces such as keyboards and soft surfaces such as clothing, for up to three months.