Hand hygiene.pdf

for its ability to reduce the release of naturally present resident flora from the hands. The
basic experimental design of these methods is summarized below.
In Europe, the most commonly used methods to test hand antiseptics are those of the
European Committee for Standardization (CEN). In the USA, such formulations are regulated
by the Food and Drug Administration (FDA) 135 , which refers to the standards of the
American Society for Testing and Materials (ASTM) in its Tentative Final Monograph (TFM).
It should be noted that the current group of experts recommend using the term efficacy to
refer to the (possible) effect of the application of a hand hygiene formulation when tested in
laboratory or in vivo situations. In contrast, they would recommend using the term effectiveness
to refer to the clinical conditions under which hand hygiene products have been tested,
such as field trials, where the impact of a hand hygiene formulation is monitored on the rates
of cross-transmission of infection or resistance 136 .
8.1.1 METHODS TO TEST ACTIVITY OF HYGIENIC HANDWASH AND HANDRUB
AGENTS (SEE TABLE I.8.1.)
The following in vivo methods use artificial contamination to test the capacity of a formulation
to reduce the level of transient microflora on the hands without regard to the resident
flora. The formulations to be tested are hand antiseptic agents intended for use by HCWs
except in the surgical area.
CEN STANDARDS
In Europe, the most common methods for testing hygienic hand antiseptic agents are EN
1499 137 and EN 1500 138 . Briefly, these methods require 12–15 volunteers and a culture of E.
coli. Volunteers are assigned randomly to two groups where one applies the test formulation
and the other a standardized reference solution. In a consecutive run, the two groups
reverse roles (cross-over design).
If an antiseptic soap has been tested according to EN 1499 137 , the mean log 10
reduction
by the product must be significantly higher than that obtained with the control (soft soap).
For handrubs (EN 1500), the mean acceptable reduction with a test formulation shall not
be significantly lower than that with the reference alcohol-based rub (isopropyl alcohol or
isopropanol 60% volume).
ASTM STANDARDS
ASTM E-1174 139
Currently, handwash or handrub agents are evaluated using this method in the USA. The
TFM criteria for efficacy are a 2-log 10
reduction of the indicator organism on each hand
within 5 minutes after the first use, and a 3-log 10
reduction of the indicator organism on
each hand within 5 minutes after the tenth use 135 .
The performance criteria in EN 1500 and in the TFM for alcohol-based handrubs are not
the same 1,135,138 . Therefore, a formulation may pass the TFM criterion but may not meet
that of EN 1500 or vice versa 140 . It should be emphasized here that the level of reduction in
microbial counts needed to produce a meaningful drop in the hand-borne spread of nosocomial
pathogens is not yet known 1,13 .
ASTM E-1838 (fingerpad method for viruses) 141
The fingerpad method can be applied with equal ease to handwash or handrub agents.
When testing handwash agents, it can also measure reductions in virus infectivity after
exposure to the test formulation alone, after post-treatment water rinsing and post-rinse
drying of hands. This method also presents a lower risk to volunteers because it entails con-