Hand hygiene.pdf

still considered the standard of care and alcohol-based handrub is reserved for particular
situations only (i.e. emergency, no sinks available) 16 .
WHO publications addressing infection control measures to reduce the spread of
pathogens in health-care settings have emphasized hand hygiene as a key measure 17-19 .
However, the guidance referring to hand hygiene technique has so far not clearly classified
handrubbing as the gold standard when compared to handwashing with soap and water.
The recommendations for the control of MRSA suggest handrubbing as an alternative “in
the absence of good water supply or running water” 17 . Two recent WHO infection control
guidelines provide a more detailed description of the handrubbing technique, and suggest
that hand hygiene be performed by either handwashing or handrubbing, but without stating
any advantage of one over the other 18,19 .
3. NORMAL BACTERIAL FLORA ON HANDS
In 1938, Price 20 established that bacteria recovered from the hands could be divided into
two categories, namely transient or resident. The resident flora consists of microorganisms
residing under the superficial cells of the stratum corneum, and can also be found on the
surface of the skin 21 . Staphylococcus epidermidis is the dominant species 22 , and oxacillin
resistance is extraordinarily high, particularly among HCWs 23 . Other resident bacteria
include Staphylococcus hominis and other coagulase-negative staphylococci, followed
by coryneform bacteria (propionibacteria, corynebacteria, dermobacteria, and micrococci)
24 . Among fungi, the most common genus of the resident skin flora, when present, is
Pityrosporum (Malassezia) spp. 25 . Resident flora has two main protective functions: microbial
antagonism and the competition for nutrients in the ecosystem 26 . In general, resident
flora is less likely to be associated with infections, but may cause infections in sterile body
cavities, in the eyes, or on non-intact skin 27 .
Transient flora, which colonizes the superficial layers of the skin, is more amenable to
removal by routine handwashing. Transient microorganisms do not usually multiply on the
skin, but they survive and sporadically multiply on skin surface 26 . They are often acquired by
HCWs during direct contact with patients or contaminated environmental surfaces adjacent
to the patient, and are the organisms most frequently associated with health care-associated
infections (HCAIs). Some types of contact are more frequently associated with higher levels
of bacterial contamination of HCWs’ hands during routine neonatal care: respiratory secretions,
nappy/diaper change and direct skin contact 28,29 . The transmissibility of transient flora
depends on the species present, the number of microorganisms on the surface, and the skin
moisture 30,31 . The hands of some HCWs may become persistently colonized by pathogenic
flora such as S. aureus, Gram-negative bacilli, or yeast 32 .
Normal human skin is colonized by bacteria, with total aerobic bacterial counts ranging
from more than 1 x 10 6 colony forming units (CFU)/cm 2 on the scalp, 5 x 10 5 CFU/cm 2 in
the axilla, and 4 x 10 4 CFU/cm 2 on the abdomen to 1 x 10 4 CFU/cm 2 on the forearm 33 . Total
bacterial counts on the hands of HCWs have ranged from 3.9 x 10 4 to 4.6 x 10 6 CFU/cm 2
20,34-36 . Fingertip contamination ranged from 0 to 300 CFU when sampled by agar contact
methods 28 . Price and subsequent investigators documented that although the number of
transient and resident flora varies considerably among individuals, it is often relatively constant
for any given individual 20,37 .