Surgical masks: operative field contamination following visor-to-visor contact

Background: Clashing of surgical visor masks frequently occurs when two surgeons bend over an operative field simultaneously; however, it is unknown whether this results in contamination. The purpose of the present study was to determine the potential for operative field contamination following surgical visor-mask clashes. The nature of bacterial contamination was also assessed. Methods: Thirty sham operative procedures were performed under normal operating conditions for a specified time period. The number of surgical visor mask clashes during each procedure was determined by randomization (0, 1, 2, 3, 4 or 6 clashes). All procedures were performed over a standard blood agar plate array. The degree of bacterial contamination was assessed by counting c.f.u. that developed after 24 h of incubation. Bacterial types were also determined. Results: Surgical visor mask clashes resulted in increased contamination of the operative field; however, this was found to be independent of the number of clashes. 95% of pathogens were coagulase negative Staphylococcus species. Other bacteria included Micrococcus species, Bacillus species, Corynebacterium species, various Gram negative bacilli and Staphylococcus aureus (< 1%). Conclusion: Surgical visor mask clashes increase the risk of bacterial contamination of the operative field.