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

<strong>WHO</strong> GUIDELINES ON HAND HYGIENE IN HEALTH CARE
11.
Review of preparations used for hand hygiene
11.1 Water
The purpose of routine handwashing in patient care is to remove
dirt and organic material as well as microbial contamination
acquired by contact with patients or the environment.
While water is often called a “universal solvent”, it cannot directly
remove hydrophobic substances such as fats and oils often
present on soiled hands. Proper handwashing therefore requires
the use of soaps or detergents to dissolve fatty materials and
facilitate their subsequent flushing with water. To ensure proper
hand hygiene, soap or detergent must be rubbed on all surfaces
of both hands followed by thorough rinsing and drying. Thus,
water alone is not suitable for cleaning soiled hands; soap or
detergent must be applied as well as water.
11.1.1 Association of water contamination with infections
Tap water may contain a variety of microorganisms including
human pathogens. Tables I.11.1 and I.11.2 list known or
suspected waterborne pathogens, together with their health
significance, stability in water, and relative infectivity. 228
11.1.2 Microbially-contaminated tap water in health-care
institutions
Tap water in health-care institutions can be a source of
nosocomial infections. A Medline search from 1966 to 2001
found 43 such outbreaks, of which 69% (29) could be linked
by epidemiological and molecular evidence to biofilms (a
community of microorganisms growing as a slimy layer on
surfaces immersed in a liquid) in water storage tanks, tap
water, and water from showers. 229-232 Pathogens identified
in waterborne nosocomial infections include: Legionella
spp., P. aeruginosa, 233,234 Stenotrophomonas maltophilia, 235
Mycobacterium avium, 236 M. fortuitum, 237 M. chelonae, 238
Fusarium spp., 239 and A. fumigatus. 240 Even if hand hygiene
practices are in place, a plausible route for transmitting these
organisms from water to patient could be through HCWs’
hands if contaminated water is used to wash them. <strong>WHO</strong> has
developed a reference document on Legionella spp. and the
prevention of legionellosis which provides a comprehensive
overview of the sources, ecology, and laboratory detection
of this microorganism. 241 It should be noted, however, that
Legionella spp. are transmitted primarily through inhalation of
aerosolized or aspirated water.
A Norwegian study to determine the occurrence, distribution,
and significance of mould species in drinking-water found 94
mould species belonging to 30 genera, including Penicillium,
Trichoderma, and Aspergillus spp. Of these, Penicillium spp.
were abundantly distributed and appeared to survive water
treatment. Although heating of water reduced the levels of
fungal contamination, A. ustus appeared to be somewhat
resistant to such treatment. Potentially pathogenic species
of fungi in tap water may be particularly important in settings
where immunocompromised patients are housed. 242
11.1.3 Tap water quality
Tap water, in addition to being a possible source of microbial
contamination, may include substances that may interfere
with the microbicidal activities of antiseptics and disinfectants.
Examples of common water contaminants and their effects are
summarized in Table I.11.1.
The physical, chemical and microbiological characteristics of
water to be used for handwashing in health-care institutions
must meet local regulations. 228 The institution is responsible
for the quality of water once it enters the building. <strong>WHO</strong>
has developed guidelines for essential environmental health
standards in health care for developing countries. 243 In Europe,
the quality of drinkable water in public buildings is regulated
by the European Council’s Directive “Water for Human
Consumption” (Regulation 1882/2003/EC) 244 (Table I.11.3). In
France, national guidelines for health-care settings have recently
proposed microbiological standards for water quality (Table
I.11.4).
If an institution’s water is suspected of being contaminated,
it can be made microbiologically safer by filtration and/or
disinfection. 228 Disinfectants include chlorine, monochloramine,
chlorine dioxide, ozone, and ultraviolet irradiation. 228 Chlorine,
in gas or liquid form, remains the most common chemical used
for this purpose, but is prone to generating potentially toxic
by-products in the treated water. Ozone has high installation
costs; monochloramine, while being slower than chlorine in its
microbicidal action, does leave a disinfectant residual and is
also less likely to generate harmful by-products.
The first step of conventional water treatment is the removal
of as much of the organic matter and particulates as possible
through coagulation, sedimentation, and filtration. Water is
then disinfected before entering the distribution system. It
is highly desirable to maintain a disinfectant residual in the
treated water while it is in transit, in order to limit the growth
of microorganisms in the distribution system and to inactivate
any pathogens that may enter the distribution system through
cross-connections, leakage, seepage or backflow. However,
conventional levels of disinfectant residuals may be ineffective
against massive contamination influx. 245
Ultraviolet radiation is a potential alternative to chemical
disinfection of small water systems, as long as such water
is free of suspended matter, turbidity, and colour. The main
disadvantage is that ultraviolet treatment does not leave a
disinfectant residual. 246
In Japan, the regulation on water supply mandates the use of
sterile water instead of tap water for preoperative scrubbing
of hands. However, a Japanese study showed that bacterial
counts on hands were essentially the same, irrespective of
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