Contamination of high touch surfaces in clinical and research laboratory work spaces

Background: There is a potential risk for environmental contamination in laboratories working with healthcare-associated pathogens. We evaluated the frequency of contamination with Clostridium difficile spores and carbapenem-resistant gram-negative bacilli (CR-GNB) on surfaces of a clinical microbiology laboratory and research laboratories working with C. difficile and CR-GNB on a daily basis.

Methods: We collected cultures for C. difficile and CR-GNB from 19 surfaces in the clinical microbiology laboratory and 147 in the research laboratories in the middle of a work day. In the research laboratories, hands, ID badges, shoe tops, shoe soles, lab coats, and cell phones were also cultured.

Results: 

5% of surfaces cultured in the clinical microbiology laboratory were positive for C. difficile and 5% were positive for CR-GNB; C. difficile was recovered from the freezer door and CR-GNB was recovered from a sink. Of 147 surfaces cultured from the research laboratory, 22 (15%) were positive for C. difficile and 2 (1.4%) were positive for CR-GNB. Eighteen of the 23 (78%) C. difficile isolates were recovered from surfaces in the laboratory that worked with C. difficile. Sites contaminated with C. difficile included floors, pipets, sinks, bench tops and laboratory equipment. C. difficile was also recovered from 3 of 7 (43%) shoe soles 2 of 7 (29%) shoe tops of personnel working in the C. difficile laboratory.

Conclusion: 

Environmental contamination with C. difficile spores was common in the clinical microbiology laboratory and in research laboratories. Our findings suggest that there is a need for improved protocols for decontamination of high-touch surfaces in laboratory settings.