Infection Prevention & Ice Machines

Alaska Infection Prevention Conference

October 8, 2019

Larry Lee, CIH

Pacific Industrial Hygiene LLC

pacific.ih@comcast.net

© Larry Lee 2019

Introduction

• My first encounter with ice machines• Residential behavioral health hospital

• Two elderly patients die from legionellosis• Life-long smokers• Alcohol dependency• Underlying illness

Introduction• Investigate water sources

• Campus & building• Cooling towers

• Patients confined to bed• Windows sealed• HVAC system filtration

• Hot water tanks• 165⁰F

• Primary sources• Sink & shower

• No shower use• Tooth brushing possible• Bathing wipes

• Food service• Parenteral nutrition• Consumed only ice

Sampling

• Sinks & showers• Hot & cold water – none detected• Faucets/tap – none detected• Shower heads – none detected

Sampling

• Ice machine• Charcoal filter for taste

• Results• Ice (water) supply tubing – 750 CFU/tube• Reservoir float – 900 CFU/swab• Drinking water supply tubing – 3,160 CFU/swab• Dispensed water – 4.4 CFU/ml• Source water – none detected• Filter(s) & post-filter water - none detected

Ice becomes my enemy• Outbreaks associated with ice

machines• Legionella• Pseudomonas aeruginosa• Pseudomonas fluorescens• Non-tubercular

mycobacterium• Enterobacter cloacae

• And they can grow mold

Contributing factors for microbial growth

• Carbon water filters• Removes chlorine

• Rapid water to ice times (30 seconds)• Plastic parts & hoses

• Conducive to biofilm growth

• Difficult to clean• Low use machines

• Limited water flow/turnover

• Critical design deficiencies

Ice machines

• Storage• Reservoir• Water tube

• Compressor

Design deficiencies

Heat risesCompressor location:

Warms the ice water reservoirWarms the various water tubesMelts ice in the storage bin

Insulated but not refrigerated

Operational challenges

• Splash back at dispensers• Hands• Dirty cups

• Refilling used cup/container

• Powdered drinks• Crystal light• Coffee creamer• Coffee

• Misuse• Drink & food storage

in the ice bin

Cleaning challengesDisassembly is necessary for EVS cleaning – ice chute

Cleaning

• Manufacturer recommendations (general)

• Annual or bi-annual cleaning • Run liquid de-scaler &

sanitizing solutions• More if necessary

• Disassemble, soak, wipe & rinse internal parts with sanitizer

• Hopper lid, bin, wheel, dispense chutes, drain pan & grill

Alternative cleaning

• Run liquid de-scaler & sanitizing solutions per manufacturer

• Cleaning facility• Highly filtered water• Supplemental ozonation

Alternative cleaning

• Break down critical parts for cleaning

• Reservoir & cover

• Water & ice tubing

Alternative cleaning

• Disassembly for cleaning

• Drain cup and cover

Alternative cleaningRemove wheel from bin

Alternative cleaning• Remove ice auger internal

components for cleaning & sanitizing

Alternative cleaning

Soak parts in bucket with sanitizing solution

Alternative cleaning• Wipe down

now accessible parts

• Bin, drip pans, water channels

• Bristle brush out water channels

• Hot water rinse

Alternative cleaningSteam clean machine

Alternative cleaning

Steam clean reservoirSensors & float

Alternative cleaning

• Clean & brush soaking components

• Rinse and dry

Alternative cleaning• Ozonated

water spray• Machine• Components

Alternative cleaning• Validate

cleaning• ATP testing• 150 </= units

for surgical instruments

• <100• Reclean if

>100

Alternative cleaning – at 6 months

Item Pre-clean Post-clean

Ice water reservoir 3,091 51

Bin – under wheel 439,887 60

Bin wall 41 39

Alternative cleaning• Re-assemble machine• Outside steam cleaning

Alternative cleaning

• Is this necessary because we tend not to find excess bacteria in dispensed water and ice?

• We do find them in dispensed water and ice but not with the frequency & concentrations found on surfaces

• Biofilm and bacteria can be released from surfaces into the water and ice at almost anytime – but it can’t be predicted when

• Manufacturer mandated cleaning is not as comprehensive as the alternative cleaning

• Who’s cleaned ice machine would you rather use?

Conclusion

• Ice machines provide an opportunity for the growth of biofilm and waterborne bacteria

• Ice machines have been associated with disease outbreaks• Manufacturer’s cleaning requirements are generally not

comprehensive• Alternative, comprehensive cleaning is superior