Evaluation and quantitative microbial risk assessment of a unique antimicrobial agent for hospital surface treatment

Background: It is generally agreed that contaminated hospital surfaces play a role in the transmission of hospital-acquired infections (HAIs). The ability of an antimicrobial agent, engineered at Emory University, to reduce bacterial bioburden on hospital surfaces was examined. A quantitative microbial risk assessment was also conducted to quantify the potential reduction of human health risks associated with application of this antimicrobial product.

Methods: A 1-arm, prospective observational study was conducted. High-frequency contact surfaces within 18 hospital patient rooms were sampled in between patient use. Negative binomial regression with repeated measures was used to examine log CFU/100 cm(2) reductions in total, gram-negative, and Staphylococcus aureus microorganisms. Standard risk assessment methods were used.

Results: Multivariate regression demonstrated significant reductions in gram-negative (P < .0001) and S aureus (P = .009) bacteria with increasing patient turnover. No reduction was observed in total bacteria (P = .93). Infection risks were reduced by 4 and 3 logs for gram-positive and gram-negative bacteria, respectively. These risk reductions, along with HAI survey studies, suggest that application of this antimicrobial product could prevent as many as 5%-10% of HAIs.

Conclusions: This study was the first evaluation of a distinctive antimicrobial agent for hospital surface treatment. The findings provide support for the utility of an antimicrobial product in potentially reducing HAI transmission from contaminated environment surfaces.