Hand hygiene.pdf

treatment selectively removes glycerolipids and sterols from the skin, this suggests that
these lipids are necessary though perhaps not sufficient in themselves for a barrier function.
Detergents (see below) act similarly to acetone on the intercellular lipid area. The return to
normal barrier function is biphasic: 50–60% of barrier recovery is typically seen within 6
hours but complete normalization of barrier function requires 5–6 days.
5. TRANSMISSION OF PATHOGENS ON HANDS
Transmission of health care-associated pathogens from one patient to another via HCWs’
hands requires five sequential elements: (i) organisms are present on the patient’s skin, or
have been shed onto inanimate objects immediately surrounding the patient; (ii) organisms
must be transferred to the hands of HCWs; (iii) organisms must be capable of surviving for
at least several minutes on HCWs’ hands; (iv) handwashing or hand antisepsis by the HCW
must be inadequate or entirely omitted, or the agent used for hand hygiene inappropriate;
and (v) the contaminated hand or hands of the caregiver must come into direct contact
with another patient or with an inanimate object that will come into direct contact with the
patient. Evidence supporting each of these elements is given below.
5.1 ORGANISMS PRESENT ON PATIENTS’ SKIN OR IN THE INANIMATE
ENVIRONMENT
Health care-associated pathogens can be recovered not only from infected or draining
wounds, but also from frequently colonized areas of normal, intact patient skin 38-49 . The
perineal or inguinal areas tend to be most heavily colonized, but the axillae, trunk, and
upper extremities (including the hands) also are frequently colonized 41,42,44,45,47,49,50 . The
number of organisms such as S. aureus, Proteus mirabilis, Klebsiella and Acinetobacter spp.
present on intact areas of the skin of some patients can vary from 100 to 10 6 CFU/cm 2
42,44,48,51 . Diabetics, patients undergoing dialysis for chronic renal failure, and those with
chronic dermatitis are particularly likely to have areas of intact skin that are colonized with
S. aureus 52-59 . Because nearly 10 6 skin squames containing viable microorganisms are shed
daily from normal skin 60 , it is not surprising that patient gowns, bed linen, bedside furniture
and other objects in the immediate environment of the patient become contaminated with
patient flora 49,61-64 . Such contamination is particularly likely to be due to staphylococci
or enterococci, which are more resistant to dessication. Contamination of the inanimate
environment has also been detected on ward handwash station surfaces, and many of the
organisms isolated were staphylococci 65 . Tap/faucet handles were more likely to be contaminated
and be in excess of benchmark values than other parts of the station. This study
emphasizes the potential importance of environmental contamination on microbial crosscontamination
and pathogen spread 65 .
5.2 ORGANISMS TRANSFERRED TO HEALTH-CARE WORKERS’ HANDS
Relatively few data are available regarding the types of patient-care activities that result in
transmission of patient flora to HCWs’ hands 28,45,63,64,66-69 . In the past, attempts have been
made to stratify patient-care activities into those most likely to cause hand contamination 70 ,
but such stratification schemes were never validated by quantifying the level of bacterial
contamination that occurred. Casewell & Phillips 67 demonstrated that nurses could contaminate
their hands with 100 to 1000 CFU of Klebsiella spp. during “clean” activities such