Managing Legionella in Water Systems During the COVID-19 Pandemic

While water systems may not seem to be high on the priority list during the COVID-19 pandemic it is important for the health and safety of staff, patients and visitors that water systems are managed safely. Evidence from China (Zhou et al., 2020) is that half of COVID-19 fatalities had experienced a secondary infection. This suggests patients are at increased risk of secondary infections both during recovery and for some months after.

In the US and Europe just under 10% of community acquired cases of Legionnaires’ disease (pneumonia) prove fatal. If acquired in healthcare settings, the death rate can rise to >25%. The potential risks for Legionnaires’ disease and other waterborne infections may well be overlooked when planning for a rapid increase in the number of patients during the COVID-19 pandemic. This includes those suffering from COVID-19 and those transferred out of hospitals to make room for COVID-19 patients. They may have both an increased susceptibility to co-infection with other pathogens, including Legionella, during the pandemic as well as during the recovery and the gradual return to normal activities.

It is important to remember that water delivered to building and facility water system outlets is not sterile, even when complying with drinking water standards such as the SDWA (Safe Drinking Water Act) in the US. In systems which are not well designed or managed, microorganisms which are naturally occurring in water, including Legionella and Pseudomonas aeruginosa, can grow, colonize in biofilm and increase to levels which can cause severe illness and even death in very susceptible patients and staff. Legionnaires’ disease results when susceptible individuals become infected after inhaling fine mist or aerosols of water containing Legionella bacteria into their lungs from such simple water system devices as sink faucets and showerheads. This also includes any associated water systems or devices such as equipment used for ventilation and humidification. Aspiration is another potential mode of infection especially in those patients with swallowing difficulties, nasogastric feeding tubes or when sucking ice.

What sort of buildings is this guidance aimed for?

This guidance is aimed at healthcare facilities, care homes, nursing homes and other residential settings where there are patients and residents being treated for COVID-19 or for patients with increased susceptibility to infections such as those transferred from hospitals to make way for COVID-19 patients. The ongoing COVID-19 pandemic has a significant potential to increase the risks of waterborne infections, including Legionnaires’ disease. It is essential that appropriate testing of water systems and patients is carried out to protect both patients and staff from unrecognized outbreaks of waterborne infections including those caused by Legionella.

Where should I start?

Establish or consult with the multidisciplinary water management program Team or other person(s) responsible for water safety within the organization, using external expertise where needed. This should be done before plans are put in place to make changes to the water system such as adding temporary wards, wash hand basins, showers etc. and / or where additional equipment needs to be installed. Water systems and associated equipment should have up to date risk assessments and water management plans for controlling risks from Legionella. Where risk assessments and management plans are not up to date, or where there are any planned alterations or installation of additional equipment, the risk assessments and proposed water management plans should be appropriately reviewed. Advice should be sought from appropriate competent and experienced external consultants where required.

Factors which increase the risk of waterborne infections in staff and highly susceptible patients as a result of the COVID-19 response include:

• Difficulties in applying routine control measures, performing routine maintenance, monitoring, audit and supervision activities associated with healthcare and other public facilities due to movement restrictions, shutdowns, staff shortages due to illness or isolation and financial restraints.
• Rushed planning, specification, installation, commissioning etc. of changes to water systems or of installing equipment for COVID-19 patients, or patients moved from a hospital setting to make way for COVID-19 patients, such as additional point of use fittings, ventilators, humidification equipment, additional showers and clinical wash hand basins etc. without proper risk assessment and input from the water management team or competent water safety specialists.
• The use of temporary equipment such as mobile wash hand stations which have not been fully drained and dried before storing may be contaminated with waterborne pathogens such as
• Interruption or disruption to routine water maintenance due to local isolation policies, staff shortages, illness, site closures / shutdowns or financial constraints.
• Reduction in testing for Legionella leading to under-recognition of contaminated sources, outbreaks cases and clusters especially when there are staff shortages due to illness or self-isolation.
• Increased patient and staff occupancy putting a strain on the ability to provide sufficient hot and cold water with adequate temperature recovery times.
• Increased numbers of patients requiring respiratory support and assistance with care.

Special requirements for water quality standards

Where there are special water quality standards required such as for dialysis, water used for humidification, ventilators, oxygen delivery etc., expertise should be sought from the relevant specialist suppliers. You should develop, and or modify, the water management plan (this can be by annotating the existing WMP by hand or adding an addendum) and ensure all actions are agreed by the team. Document how you will protect patients, staff, visitors and others from the presence of waterborne pathogens including Legionella. If required, get help from an experienced and competent water treatment advisor, public health or environmental health authorities.

Where local, state or national guidelines or legislation is in place then you must follow these.

Key points to remember

It is important to remember that Legionella and other waterborne pathogens of relevance in healthcare settings will grow in water systems to levels which may cause infection: 

• Where the water temperature >77°F and <122°F. This does not have to be in the entire system, just relatively small areas of the system pipework for example, at these temperatures will allow Legionella to grow which, can then contaminate and spread to other parts of the system and subsequently make it difficult to control their growth. It is important to prevent the hot water from cooling and the cold from warming!
• Where there is stagnation as a result of poor or no water flow.
• Where there is a means of creating and disseminating inhalable droplets such as the aerosols generated by evaporative air conditioning and humidification systems, operating taps, showering, flushing toilets, or when using other equipment such as humidifiers, nebulizers etc. or water which can be aspirated.
• There is a need to maintain awareness of the risks from infections due to water, including legionellosis, during the COVID-19 pandemic.
• Care must be taken to ensure control measures are maintained in all water systems despite the difficult COVID-19 situation e.g. temperature, biocides (where applicable, flushing of infrequently used water outlets etc.).
• Proper risk assessment must be undertaken, especially before changes to water systems are being considered, including the performance of routine inspections.
• Healthcare professionals should remain vigilant to allow detection of legionellosis in appropriate clinical circumstances.

Let IWC Innovations Help Keep Your Building Safe From Legionella & other Waterborne Disease. 

ESGLI - https://www.pwtag.org/esgli-guidance-managing-legionella-building-water-systems-covid-19-pandemic/