Assessment of aerobic bacterial contamination of computer keyboards in a tropical setting

Computers are widely used in healthcare for improved and effective care. Previous published reports have shown microorganisms colonising computer keyboards in some clinical areas.

This study was undertaken to measure, compare and characterize the aerobic microorganisms in computer keyboards of hospital and non-hospital settings.

Samples were collected from commonly used keys of computers in hospital and non-hospital settings using moistened sterile swabs, inoculated in liquid and solid media, and incubated aerobically at 37 degrees C for 24-48 h. Growth was identified as per standard microbiological procedures. Antibiotic susceptibility was determined for pathogenic strains by Kirby-Bauer method.

Growth was seen in all 80 samples (40 from each setting). Staphylococcus aureus was isolated from both settings (hospital: 6 MRSA, 11 MSSA; non-hospital: 4 MRSA, 9 MSSA). Gram-negative bacilli were isolated more frequently from hospital (33%). Statistical analysis showed homogeneity among isolates from computer keyboards in both settings, except for Pseudomonas.

Isolation of microorganisms from "high-touch" surfaces such as computer keyboards is indicative of the need for awareness on cleaning of such surfaces or disinfection and adequate hand hygiene.