Hand hygiene.pdf

Table I.8.1:
Basic experimental design of current methods to test the efficacy of hand hygiene
and surgical hand preparation formulations
Method no. Test organism(s) Basic procedure
EN 1499
(hygienic
handwash)
EN 1500
(hygienic
handrub)
ASTM E-1174
(effectiveness
of health-care
worker or
consumer
handwash
formulation)
ASTM E-1838
(fingerpad
method for
viruses)
Escherichia coli
(K12)
Escherichia coli
(K12)
Serratia marcescens;
Escherichia coli
Adenovirus,
rotavirus, rhinovirus
and hepatitis A virus
Hands washed with a soft soap, dried, immersed
in broth culture for 5 s, excess fluid drained off,
and air-dried for 3 min. Bacteria recovered for the
initial values by kneading the fingertips of each
hand separately for 60 s in 10 ml of broth without
neutralizers. Hands removed from the broth and
treated with the product following the manufacturer’s
instructions (but for no longer than 1 min)
or the reference solution (a 20% solution of soft
soap). Recovery of bacteria for final values (see
EN 1500).
Basic procedure for hand contamination and initial
recovery of test bacteria same as in EN 1499.
Hands rubbed for 30 s with 3 ml of isopropanol
60% V/V; same operation repeated with a total
application time not exceeding 60 s. The fingertips
of both hands rinsed in water for 5 s and
excess water drained off. Fingertips of each hand
kneaded separately in 10 ml of broth with added
neutralizers. These broths are used to obtain the
final (post-treatment) values. Log10 dilutions of
recovery medium containing neutralizer are
prepared and plated out. Within 3 h, the same
volunteers tested with the reference formulation
or the test product. Colony counts obtained and
log reductions calculated.
To test the efficacy of handwash or handrub
agents on the reduction of transient microbial
flora. Before baseline bacterial sampling and
prior to each wash with the test material, 5 ml
of a suspension of test organism are applied to
and rubbed over hands. Test material put onto
hands and spread over hands and lower 1/3 of
forearms with lathering. Hands and forearms
rinsed with water. Elutions are performed after
required number of washes using 75 ml of eluent
for each hand in glove. The eluates are tested for
viable bacteria.
10 μl of the test virus suspension in soil load
placed at the centre of each thumb- and fingerpad,
the inoculum dried and exposed for 10–30
sec to 1 ml of test formulation or control. The
fingerpads then eluted and eluates assayed for
viable virus. Controls included to assess input
titre, loss on drying of inoculum and mechanical
removal of virus. The method applicable to testing
both handwash and handrub agents.