Ice and chilled water dispensing machines
Managing ice and chilled water dispensing machines is an important step in reducing the likelihood of patients or residents of healthcare facilities contracting Legionnaires’ disease.
How is Legionnaires’ disease acquired from ice and chilled water dispensers
Legionella bacteria have been detected in high concentrations in water from ice and chilled water dispensing machines. Two factors have been identified as contributing to this. First, heat generated by the chiller compressor provides temperatures suitable for growth of Legionella in the incoming cold water lines of these machines. Second, most of these machines include carbon filtration to improve the water’s taste and odour. This has the effect of removing most residual disinfectant from the water allowing bacteria to grow in the water line, and even within the filter medium itself.
Legionnaires’ disease is usually contracted through inhalation of aerosols (very small droplets of water suspended in air) containing Legionella bacteria. However, infection can also result from a person aspirating these very small droplets of water whilst drinking melted ice or sucking on ice.
If high risk patients (as categorised by a facility) consume ice or chilled water from these devices there is an increased risk of micro-aspiration and of Legionella infection.
If non-high risk patients (as categorised by a facility) consume ice or chilled water from these devices the risk of Legionella infection is much lower.
Note: Chilled water dispensing machines may have a chilled water outlet or a combined tap that dispenses chilled and boiling water. The boiling water from combined devices does not present a Legionella risk.
Patient risk categorisation
The water risk management team or relevant staff within a facility should categorise its high risk patients as distinct from its non‑high risk patients.
Evidence suggests severely immune-compromised patients are at highest risk of acquiring legionellosis.
Additional factors to consider when categorising the patient risk include recent surgery, intubation and mechanical ventilation, as well as the potential for aspiration of water contaminated with Legionella including nasogastric feeds and the use of respiratory therapy equipment contaminated with Legionella.
High risk patients
Patients who have been categorised by a facility as high risk should not be provided with ice or chilled water from these machines (e.g. to suck on, or added to drinking water) due to susceptibility to Legionella infection. Instead, pre-boiled or micro-filtered (via a non-carbon, 0.2 micron pore size filter) tap water should be chilled or frozen in conventional style fridges or freezers for these patients.
Non-high risk patients
Patients who have not been categorised by a facility as high risk (i.e. most patients) can use ice and chilled water from these machines provided the machines have been serviced according to manufacturer’s instructions and appropriate filter selection is considered. Carbon filters remove chlorine from water and so carbon-free filters are preferred.
Ice for non-drinking purposes
Ice for non-drinking purposes (e.g. as ice packs to reduce bleeding from tissues, to reduce swelling etc.) can come from any kind of ice making process as long as the machines are serviced according to manufacturer’s instructions. This is provided the ice does not come into contact with wounds or any part of the body where the dermal integrity has been compromised (e.g. patients in a burns unit).
Ice and water from these dispensing machines, should never come into contact with clinical devices used for invasive procedures (e.g. bronchoscopes or syringes) and should be clearly marked with a sign saying “ice from this machine is not for human consumption” or words to that effect.
Verification monitoring
In high risk areas ice and chilled water should be tested as part of the verification monitoring program under the facility water risk management plan.