Antimicrobial hand hygiene products: the choice is yours

Healthcare Purchasing News, April, 2008 by Jeanne Medvick

"Increase the frequency of hand hygiene practices and decrease healthcare-associated infections (HAI)." This has been the message sent to healthcare workers to raise their awareness for the need to increase their compliance with hand hygiene practices. Unfortunately, it isn't the whole solution, nor is it always enough to motivate these individuals. There is also a need to improve the quality of hand hygiene practices by selecting antiseptic hand hygiene products that have proven antimicrobial efficacy. Increasing the frequency of hand hygiene practices using antiseptic hand hygiene products that have inadequate antimicrobial efficacy may contribute little, if anything, to reducing cross-contamination. Products with superior antimicrobial efficacy will reduce the transient, pathogenic microorganisms on the skin, decrease the risk of cross-contamination and ultimately may help drive down the incidence of HAI.

The status of healthcare-associated infections

The onset of mandatory public reporting of HAI has contributed to the sense of to improve hand hygiene practices. In the United States, it is estimated that two million HAI occur per year in hospitals, and 90,000 deaths can be directly related to these infections. Healthcare costs to manage these infections are calculated to be in excess of 4.5 billion dollars. The personal cost to the patients who develop these infections cannot be measured. Hand hygiene is considered to be the most straightforward and most effective intervention for preventing HAIs. (1)

The reality of antimicrobial efficacy

An antiseptic agent is an antimicrobial substance that is applied to the skin to reduce the number of microbial flora. In the United States, the most commonly used antiseptic agents are alcohol, iodophors, chloroxylenol, chlorhexidine gluconate and triclosan. (2)

Triclosan is a synthetic, broad-spectrum antiseptic agent that was first described in the literature ill 1967. (3) It has been used for more than 20 years in personal care products such as toothpaste and deodorants, and in antibacterial handwash products that are sold in the consumer market. Triclosan is also an antiseptic ingredient included in healthcare personnel handwash (HCPH--a term used by FDA) formulations that are intended to be used in healthcare facilities. Does this mean that all triclosan-containing hand hygiene products perform equally well against pathogenic microorganisms?

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The mere presence of an antiseptic agent in a hand hygiene product does not guarantee that there is significant antimicrobial efficacy against pathogens. Antiseptic hand hygiene products marketed in the healthcare arena should meet the proposed rigorous performance standards issued by the Food and Drug Administration (FDA). (4) The performance standards specify required in vitro (in a test tube or container) tests in addition to the minimum criteria for in vivo (with a living organism) tests such as those used for a HCPH. According to FDA, a HCPH must have fast-acting, broad-spectrum antimicrobial activity to reduce the number of transient flora on intact skin. Commercially available antibacterial hand hygiene products are not appropriate substitutes in the healthcare setting because they are not formulated to meet the testing standards of the TFM.

Time-kill methodology

A time-kill study is the most commonly used method to prove the fast-acting, broad-spectrum antimicrobial activity of an antiseptic-containing hand hygiene product. A time-kill study is an in vitro test in which a test product is challenged to kill pathogenic microorganisms in a designated time period (usually seconds) with an expected substantial reduction of microorganisms at the end of the time period. (5)

The procedure begins with specific amounts of the test product being placed in the testing container.

Next, specified amounts of microbial suspensions (microorganisms in a medium) are added to the test product to determine the antimicrobial activity of the antiseptic agent in the hand hygiene product. The contact time between test product and microorganism can vary depending on the objective of the study. In most time-kill studies, the contact time is 15 seconds.

After the contact time has been reached, a neutralizer is added to stop the antimicrobial activity of the test product. The test product will continue to interact with the microorganisms if it is not neutralized.

The final step in the process is to determine the antimicrobial efficacy of the test product by comparing the number of viable microorganisms from the original culture, known as the basel to the number of microorganisms after exposure to the test product. The results are determined by standard microbiological plate counts. (See Figure 1)

Comparing a HCPH to a householdhand hygiene product

In a recent time-kill study, a triclosan-containing HCPH formulated to meet the performance standards of FDA was compared to a triclosan-containing antibacterial soap intended for household use. The products were both challenged with 17 pathogenic microorganisms commonly found in healthcare facilities. Antimicrobial activity was evaluated at contact times of 15, 30, and 60 seconds.