WHO Guidelines on Hand Hygiene in Health Care - Safe Care ...

PART I. REVIEW OF SCIENTIFIC DATA RELATED TO HAND HYGIENE
was discontinued, a number of investigators noted that the
incidence of S. aureus infections associated with health care
in hospital nurseries increased substantially. 363,364 In several
instances, the frequency of infections decreased when
hexachlorophene bathing of infants was reinstituted. However,
current guidelines recommend against routine bathing of
neonates with hexachlorophene because of its potential
neurotoxic effects. 365 The agent is classified by the FDA TFM
as not generally recognized as safe and effective for use as an
antiseptic handwash. 198 Hexachlorophene should not be used
to bathe patients with burns or extensive areas of abnormal,
sensitive skin. Soaps containing 3% hexachlorophene are
available by prescription only. 352 Due to its high rate of dermal
absorption and subsequent toxic effects, 70,366 hexachlorophenecontaining
products should be avoided and hexachlorophene
has been banned worldwide.
11.7 Iodine and iodophors
Iodine has been recognized as an effective antiseptic since the
1800s, though iodophors have largely replaced iodine as the
active ingredient in antiseptics because iodine often causes
irritation and discolouring of skin.
Iodine molecules rapidly penetrate the cell wall of
microorganisms and inactivate cells by forming complexes with
amino acids and unsaturated fatty acids, resulting in impaired
protein synthesis and alteration of cell membranes. 367 Iodophors
are composed of elemental iodine, iodide or triiodide, and a
polymer carrier (complexing agent) of high molecular weight.
The amount of molecular iodine present (so-called “free” iodine)
determines the level of antimicrobial activity of iodophors.
“Available” iodine refers to the total amount of iodine that can
be titrated with sodium thiosulfate. 368 Typical 10% povidoneiodine
formulations contain 1% available iodine and yield free
iodine concentrations of 1 ppm. 368 Combining iodine with
various polymers increases the solubility of iodine, promotes
sustained-release of iodine, and reduces skin irritation. The
most common polymers incorporated into iodophors are
polyvinyl pyrrolidone (povidone) and ethoxylated nonionic
detergents (poloxamers). 367,368 The antimicrobial activity of
iodophors can also be affected by pH, temperature, exposure
time, concentration of total available iodine, and the amount and
type of organic and inorganic compounds present (e.g. alcohols
and detergents).
Iodine and iodophors have bactericidal activity against Grampositive,
Gram-negative and some spore-forming bacteria
(clostridia, Bacillus spp.) and are active against mycobacteria,
viruses, and fungi. 204,367,369-372 However, in concentrations used
in antiseptics, iodophors are not usually sporicidal. 373 In vivo
studies have demonstrated that iodophors reduce the number
of viable organisms that may be recovered from HCWs’
hands. 280,314,317,320,374 Povidone-iodine 5–10% has been tentatively
classified by the FDA TFM as a safe and effective (Category
I) active agent for use as an antiseptic handwash and HCW
handwash. 198 The extent to which iodophors exhibit persistent
antimicrobial activity once they have been washed off the
skin is a matter of some controversy. In a study by Paulson, 344
persistent activity was noted for six hours, but several other
studies demonstrated persistent activity for 30–60 minutes
after washing hands with an iodophor. 137,284,375 In studies where
bacterial counts were obtained after individuals wore gloves for
1–4 hours after washing, however, iodophors demonstrated
poor persistent activity. 48,271,282,360,376-381 The in vivo antimicrobial
activity of iodophors is significantly reduced in the presence
of organic substances such as blood or sputum. 204 Povidone
iodine has been found to be less effective than alcohol 60%
(v/v) and hydrogen peroxide 3% and 5% on S. epidermidis
biofilms. 382
Most iodophor preparations used for hand hygiene contain 7.5–
10% povidone-iodine. Formulations with lower concentrations
also have good antimicrobial activity, because dilution tends to
increase free iodine concentrations. 383 As the amount of free
iodine increases, however, the degree of skin irritation also
may increase. 383 Iodophors cause less skin irritation and fewer
allergic reactions than iodine, but more irritant contact dermatitis
than other antiseptics commonly used for hand hygiene. 220
Occasionally, iodophor antiseptics have become contaminated
with Gram-negative bacilli as a result of poor manufacturing
processes and have caused outbreaks or pseudo-outbreaks
of infection. 368,384 An outbreak of P. cepacia pseudobacteremia
involving 52 patients in four hospitals in New York over six
months was attributed to the contamination of a 10% povidoneiodine
solution used as an antiseptic and disinfectant solution. 384
11.8 Quaternary ammonium compounds
Quaternary ammonium compounds (QACs) are composed of
a nitrogen atom linked directly to four alkyl groups, which may
vary considerably in their structure and complexity. 385 Among
this large group of compounds, alkyl benzalkonium chlorides
are the most widely used as antiseptics. Other compounds that
have been used as antiseptics include benzethonium chloride,
cetrimide, and cetylpyridium chloride. 48 The antimicrobial activity
of these compounds was first studied in the early 1900s, and
a QAC for preoperative cleaning of surgeons’ hands was used
as early as 1935. 385 The antimicrobial activity of this group
of compounds appears to be attributable to adsorption to
the cytoplasmic membrane, with subsequent leakage of low
molecular weight cytoplasmic constituents. 385
QACs are primarily bacteriostatic and fungistatic, although
they are microbicidal against some organisms at high
concentrations. 48 They are more active against Gram-positive
bacteria than against Gram-negative bacilli. QACs have
relatively weak activity against mycobacteria and fungi and
have greater activity against lipophilic viruses (Table I.11.7).
Their antimicrobial activity is adversely affected by the presence
of organic material, and they are not compatible with anionic
detergents. 48,385
A QAC is present as a supplement in some commercially
available alcohol-based handrubs. A study on the population
kinetics of skin flora on gloved hands indicated that the effect
of an alcohol-based handrub containing mecetronium etilsulfate
(isopropanol 45% wt/wt plus n-propanol 30% wt/wt plus
mecetronium etilsulfate 0.2% wt/wt ) was not significantly
different from n-propanol 60% v/v. 227
Depending on the QAC type and formulation, the antimicrobial
efficacy can be severely affected in the presence of hard water
(if it is a diluted product) and fatty materials. Later generations
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