The Role of Contaminated Surfaces in the Transmission of Nosocomial Pathogens - Use of Biocidal Surfaces for Reduction of Healthcare Acquired Infections - page 41

prior room occupant [ 13 ]. In contrast, a recent cohort study of HPV decontamina-
tion on six ICUs found that patients admitted to rooms decontaminated by HPV
were less likely to acquire VRE than patients admitted to rooms cleaned by using
standard methods when the prior room occupant was positive for VRE (incidence
rate ratio, 0.22) [ 110 ]. This contrast perhaps illustrates the difficulty in eliminating
VRE from surfaces using conventional methods [ 80 ].
In addition to patient-level analysis, several studies have shown that improved
environmental hygiene can reduce the general incidence of VRE [ 13 , 103 , 104 ].
For example, Hayden et al. investigated the impact of environmental and
hand hygiene improvements on VRE infections in an ICU [ 82 ]. An educational
improvement program for environmental cleaning reduced the frequency of contam-
ination in the rooms of patients with and without VRE and the incidence of VRE
acquisition fell. The reduction in contamination was sustained through a “washout”
period where no further intervention occurred and through a subsequent hand hygiene
educational improvement program. A recent 4-year before-after study from Brazil
showed that an educational and observational intervention for cleaners resulted in
impressive reductions in both VRE infection and environmental contamination [ 103 ].
3.7.3 MRSA
Dancer recently reviewed evidence that environmental contamination makes an
important contribution to the transmission of MRSA [ 111 ]. That review summarized
evidence that staphylococci are carried by people and shed into the environment, can
survive for extended periods on surfaces and can spread between people and the
environment, and that improved hygiene reduces staphylococcal infection rates.
More recently, Dancer et al. conducted a ward cross-over study to investigate the
impact of an extra cleaner focusing on hand touch sites [ 106 ]. The enhanced cleaning
was associated with a significant reduction in the total aerobic counts on surfaces and
the number of failures to reach a hygienic standard of > 2.5 CFU/cm 2 and with
a significant reduction in MRSA acquisitions by patients. However, there was no
significant reduction in surface contamination with methicillin-susceptible S. aureus
and admission screening was not universally applied, so the true MRSA acquisition
rate was uncertain. Nonetheless, the study provides further evidence to support the
view that reducing surface contamination reduces MRSA nosocomial transmission.
3.7.4 Gram-Negative Rods (GNRs)
3.7.4.1 Non-fermenting Gram-negative bacteria
( Acinetobacter and Pseudomonas )
A recent prospective cohort study showed that prior room occupancy with a
patient colonized or infected with A. baumannii or P. aeruginosa was a significant