Q-279. The Effect of Antimicrobial Hand Washes on Methicillin Resistant Staphylococus aureus

A. L. Waggoner, G. A. Cole, M. H. Duran, J. L. Fuls, A. B. Petrangeli, N. D. Rodgers, G. E. Fischler;
The Dial Corp., Scottsdale, AZ.

Methicillin resistant Staphylococcus aureus (MRSA) has established itself as a major hospital pathogen and is responsible for many nosocomial infections. Recently a new strain has been found in community settings, Community Acquired Methicillin Resistant Staphylococcus aureus (CA-MRSA). The spread of this organism is believed to take place through contaminated hands and surfaces. The CDC recommends handwashing as a preventative measure in the spread of MRSA. In vitro and in vivo studies against a strain of MRSA were performed comparing the efficacy of retail hand wash products containing 0.46%, 0.6% and 1% triclosan utilizing “activated” triclosan technology, to several health care professional hand wash products, one containing 4% chlorohexadine gluconate (CHG), one containing 0.75% triclosan, and a retail hand wash with 0.2% triclosan. The time kill data showed significant reductions in MRSA with all of the activated triclosan technology formulas at both 30 and 60 seconds. The activated triclosan formula containing 0.46% produced a 2.40 log10 reduction at 30 seconds, the 0.6% and 1% both reduced MRSA >4.5 log10 within 30 seconds. The 4% CHG product achieved a 1.73 log10 reduction, the foaming healthcare product had a 1.70 log10 reduction, and the 0.2% triclosan retail product a 0.14 log10 reduction, all at 30 seconds. A Health Care Personnel Hand Wash (ASTM E1174) was performed using MRSA as the marker organism comparing the efficacy of the 0.46% activated triclosan system vs. the 4% CHG product under normal hand washing conditions. The activated triclosan formula reduced MRSA by 2.44 log10 following a single 30 second hand wash compared with 2.07 log10 for the 4% CHG. Both products met the proposed FDA reduction criteria of 2 log10 following a single wash however the activated triclosan formula’s reduction was greater and the difference was statistically significant (P <0.05). The data indicates that the concentration of an active ingredient doesn’t necessarily determine its efficacy, and that retail consumer antibacterial products when properly formulated can be more efficacious than professional healthcare products against MRSA.