Bacterial Contamination of Radiologist Workstations: Results of a Pilot Study

Purpose: The aim of this study was to quantify and characterize bacterial contamination of radiologist workstations. Methods: Dictation microphones and computer mice at the most frequently used radiologist workstations from 2 inpatient and 2 outpatient reading rooms at 2 teaching hospitals in 2 states were sampled for bacteria. Reference toilet seat and doorknob sampling was performed in the 4 restrooms nearest those reading rooms. One microphone and one mouse in each reading room were sampled again after quick disinfection with an inexpensive, commercially available antiseptic pad. Sampling was performed using direct trypticase soy agar plating, with sampled areas uniformly approximating 50 cm(2). Colonies were quantified and additionally characterized after 24 hours using mannitol salt agar and MacConkey agar. Results: All sampled radiologist computer workstation and restroom sites were contaminated with bacteria. Mean colony counts were 69.4 +/- 38.7 (range, 15-123) for microphones, 46.1 +/- 58.1 (range, 1-173) for mice, 10.5 +/- 9.7 (range, 1-22) for toilet seats, and 14.8 +/- 16.0 (range, 1-36) for restroom doorknobs. Of all workstation sites, 64.3% (9 of 14) grew Staphylococcus aureus, and 21.4% (3 of 14) grew enteric organisms. Overall microphone and mouse bacterial contamination was significantly higher than that of nearby restroom toilets and doorknobs (57.8 +/- 49.0 vs 12.6 +/- 12.5, P = .005). Microphone and mouse bacterial counts were nearly completely eliminated after brief antiseptic swabbing (from 76.9 +/- 53.2 to 0.3 0.7, P = .002). Conclusions: Bacterial contamination of microphones and computer mice at radiologist workstations is common, with colonization significantly greater than nearby restroom toilet seats and doorknobs. Simple, rapid, and inexpensive disinfection techniques nearly completely eradicate workstation bacterial contamination. The clinical implications of colonization merits further study.