Cleaning methods
Edwards, N. W. M. et al. 2020. Recontamination of Healthcare Surfaces by Repeated Wiping with Biocide-Loaded Wipes: “OneWipe, One Surface, One Direction, Dispose” as Best Practice in the Clinical Environment.
Objectives
- To study how the surface to be wiped, the type of fibre in the wipe and how the presence of liquid biocide affects the degree of recontamination.
• metal, ceramic, and plastic healthcare surfaces
• 2 different wipe compositions (hygroscopic and hydrophilic)
• with and without liquid biocide.
Results
- Despite initially high removal efficiency of >70 % during initial wiping, all healthcare surfaces were recontaminated with E. coli, S. aureus and E. faecalis when wiped more than once using the same wipe.
- Recontamination occurred regardless of the fibre composition of the wipe or the presence of a liquid biocide.
- The extent of recontamination by E. coli, S. aureus and E. faecalis bacteria also increased when metal healthcare surfaces possessed a higher microscale roughness (<1 μm).
Conclusion
“One wipe, One surface, One direction, Dispose” policy should be implemented and rigorously enforced.
Berendt, A.E. et al. 2011. Three swipes and you’re out: How many swipes are needed to decontaminate plastic with disposable wipes?
Objective
- To measure the ability of various wipes to reduce bacterial counts when swiped across plastic 1, 3, or 5 times.
Methods
- Dilutions of 0.5 McFarland (1.5 3 108 colony-forming units/ml) suspensions of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant.
- Enterococcus faecalis (VRE), and Pseudomonas aeruginosa, as well as a 2.0 McFarland suspension of Candida albicans, were prepared in sterile saline.
- To mimic contaminate surfaces, 100 ml of each suspension were streaked evenly onto sterile plastic Petri dishes and allowed to dry.
- Each dish was then rubbed 1, 3, or 5 times with
• a saline-moistened tissue (saline= water and salt, sodium chloride, NaCl), wet wiping
• a 5% ethanol wipe
• a quaternary ammonium wipe with 14.30 % isopropanol and 0.23 % di-isobutylphenoxyethyl dimethyl benzyl ammonium chloride
• a 0.5 % hydrogen peroxide wipe
• a 0.5 % chlorhexidine-70 % isopropyl alcohol wipe. - Contact time 1 second per swipe (after allowed to dry 10 min).
- The plate surfaces were then flooded with 1 ml of trypticase soy broth, to resuspend any remaining bacteria.
- 100 μl of the suspension was cultivated on blood agar plates for 24 hours and colonies calculated after that.
Results
- For all 5 wipe types, swiping the surface 3 or 5 times eliminated more bacteria than only one swipe.
- According to authors, “dramatic decreases” in bacterial counts with an increasing number of swipes, regardless of the type of wipe used (including saline-moistened tissues)
- Swiping 3 times decreased the bacterial load by 88% (on average) relative to swiping just once.
- When the surface was swiped 3 or more times, the saline wipe appeared to be equally effective as disinfectant wipes.
Conclusions
- When surfaces are swiped 3 or more times, a saline-moistened wipe appears to be just as effective as disinfectant wipes.
- When swiped only once, then a disinfectant wipe should be used.
Edwards, N. W. M. et al. 2018. Factors affecting removal of bacterial pathogens from healthcare surfaces during dynamic wiping.
Objectives
- To determine the intrinsic (e.g., wipe surface density, lotion addition to wipe) and extrinsic (e.g., wiping pressure) factors leading to the greatest bacterial removal efficiencies.
Methods
- Test microbes: E. coli, S. aureus, and E. faecalis
- Wipes were manufactured for the research in laboratory
• an inherently hydrophilic regenerated cellulose fiber (lyocell) and
• an inherently hydrophobic fiber (polypropylene – PP) were selected as raw materials for wipe fabric manufacture
• with different properties. - Wiping pressures were selected based on those produced by an average sized human hand and the median value reported in the literature.
• “Low” wiping pressure of 0.69 kN.m–2 is the equivalent of 1 kg of exerted force from an average sized human hand (‘‘hand-weight’’).
• “Medium” wiping pressure of 4.68 kN.m–2 is equivalent to 6.79 kg ‘‘handweight’’. This was selected by extrapolating the 150 g ‘‘exerted weight’’ used by Ramm et al. in their wiping experiments.
• “High” 13.80 kN.m–2 wiping pressure is the equivalent of 20 kg ‘‘hand-weight’’. - The influence of a biocidal liquid was compared with distilled water and dry controls
• Biocide was a blend of a non-ionic surfactant (C9–C11 ethoxylated alcohol pareth-5), a cationic surfactant (benzalkonium chloride) and various buffering agents and sequestrants. - Wiping done with a certain rotation device 60 r min–1 for 10 s at either 0.68, 4.69 or 13.80 kN.m–2.
Results
- The addition of a biocide to a wipe has the greatest effect on bacterial removal %.
- The improvement in wiping efficiency due to the addition of the biocidal liquid might also be partly due to the presence of a liquid phase, and not just the fact that it is a biocidal liquid.
- The addition of water alone can substantially increase bacteria removal from the surface by providing a transport medium in which bacteria can be suspended and transported by the interstitial pore spaces within the wipe fabric structure.
- The heaviest wipes, 150 g.m–2, consistently yielded greater bacteria removal efficiency than the 50 and 100 g.m–2 wipes (more fibers, more contacts on surface, more removal).
Conclusions
- Best practice for infection control should involve
• use of heavier weight
• regenerated cellulosic wipes
• impregnated with biocide
• with as much wiping pressure as possible.
Andersen, B. M. et al. 2009. Floor cleaning: effect on bacteria and organic materials in hospital rooms.
Objectives
- To examine the load of organic materials and bacteria (colony-forming units: cfu) on the floors in patient rooms during ordinary use.
- To compare the results of two different ATP devices.
- To study the effect of four floor cleaning methods on the presence of organic materials and bacteria.
- Methods: dry, spray, moist and wet mopping.
Methods
- For assessment of soiling: ATP (from floor) and microbiological samples (from floor and air).
- An SAS air sampler was used to take air samples before and after cleaning.
- Agent: detergent (Allrent) and water.
- Four two-bed rooms, floor material: vinyl
- Swep mops, moved in a figure of 8
• dry mopping: 50 cm, 100 % microfibre
• spray mopping: 50 cm, dry mop, 95 % microfibre, 150-200 ml water with detergent was added to the floor before washing
• moist mopping: mop as above, was moist after washing at temperature up to 85°C and centrifugation for 3-5 min, put in a clean plastic bag and placed in cooler until next morning
• wet mopping: Blue Swep mop, polyester fibre 50 % and viscose 50 %. The mop was moistened in 3 l detergent water 40°C before washing over the area, followed by dry mopping over the same area, but inside the wet area. - Sampling
• Just before, and within 10 min after cleaning.
• Floor samples were not taken from visibly stained areas.
• ATP samples were taken first, then the microbiological samples.
• Samples were taken at three different positions before and after cleaning.
Results
- Organic soil removal
• Presence of organic materials varied between rooms and days.
• All methods reduced organic material on the floors, but wet and moist mopping seemed to be the most effective.
• Cleaning reduced organic material to 5-36 % of the level present before cleaning, depending upon mopping method. - Removal of microbes
• Bacteria on the floor showed a large day-to-day variation.
• Before cleaning, the mean bacterial count was 83 cfu/20 cm2.
• A mean of around 60 % of cfu was removed by dry, moist and wet mopping, but only 30 % by the spray mopping.
• All four methods reduced the bacteria on the floor from 60-100 to 30-60 cfu/20 cm2. - Mopping effect on cfu/m3 air
• No significant difference between the four mopping methods concerning effect on bacteria in air but after mopping, the mean numbers of cfu/m3 air increased for all four methods.