The vital importance of testing for Legionella in hospitals and care homes

As if the fatal consequences of Legionnaires’ disease weren’t motivation enough, hospitals and healthcare facilities are also expected to have procedures and policies when it comes to their water management, in order to minimise the risk of Legionella and other opportunistic pathogens in their water systems. This means that the authorities will also scrutinise waterborne pathogens as well as WMPs or water management programs during accreditation surveys to make sure they follow the official requirements. Hospitals and healthcare facilities that can’t demonstrate measures to reduce the risk of Legionella are at risk of citation for non-compliance. Fortunately, with the right Legionnaires’ disease prevention techniques and practices, the spread of this bacteria is totally preventable and the risks can be managed.

Up to thirty per cent of sporadic cases of healthcare facility-acquired pneumonia are actually caused by Legionella. This bacteria can achieve high numbers in the hot-water systems of buildings such as healthcare facilities or hospitals. Legionella can be found in the water supply in small numbers but is amplified significantly in the hospital’s hot-water system. This is encouraged by water temperatures below fifty degrees Celsius, sludge formation, areas of stagnation and the presence of other bacteria and the materials utilised in the piping. The formation of aerosols from contaminated water droplets is one of the main ways to spread Legionella, but there is evidence that suggests the aspiration is also a way of entry. Control involves a mixture of chemical and physical methods combined with quality plumbing practices (like the elimination of dead-legs or arrangement of pumps). Adequate control requires significant attention to detail from qualified professionals who have completed thorough Legionella training.

The cases of hospital-acquired Legionnaires’ disease have constantly been on the rise worldwide, and research shows that Legionella is present in at least twelve per cent of all hospital water systems. A recent study found that nineteen per cent of cases are actually associated with long-term care home facilities and at least fifteen per cent with hospitals. Legionnaires’ disease can be life-threatening unless treated rapidly. This is particularly true in healthcare and care home facilities where the mortality rates can be as high as forty per cent because of the vulnerability of patients and residents. Such care facilities need to be aware of these risks and should aim to reduce risk factors to virtually zero.

Why is Legionella bacteria dangerous?

Legionella growth is very common in potable and utility water systems — such as condenser water systems, cooling towers, showers, faucets, tanks or air conditioning units. It grows easily in stagnant water. This can actually become an issue in healthcare facilities and hospitals when water systems experience underuse; for instance, a shower or faucet in the ICU that is not receiving enough use.

If the growth of Legionella bacteria eventually goes undetected, patients and other users could become susceptible to breathing in airborne mist from contaminated water droplets, which can ultimately lead to the development of Legionnaires’ disease. This is a form of pneumonia, generally lethal in about ten per cent of cases. But this number can jump to forty per cent for hospital patients or elderly people who may already be immunocompromised.

Factors that can affect an increased risk of Legionella

• • Vulnerable individuals: Healthcare facilities and hospitals are high-risk areas for Legionella due to the high number of vulnerable patients present. People who have a weakened or deteriorated immune system, have gone through recent surgery or who need respiratory equipment are at a higher risk of being infected with the disease. The elderly and newborn babies, as well as smokers, are also more susceptible to infection.
  • Aerosols: Legionnaires’ disease can actually be caught from any water source that produces aerosols or spray, but some of the most common sources of infection in a hospital or healthcare setting are humidifiers, birthing pools, showers as well as respiratory devices.

• Design: Old or complex pipework with dead legs, and also water systems where water is kept under fifty degrees can pose a threat, since they provide the ideal conditions for Legionella growth. This is a serious issue in ageing facilities and also in newly renovated facilities. Failure to keep an up to date or proper pipework can compromise the risk assessment and leave high-risk areas of the system unmonitored.
• Water management: Regular cleaning as well as the disinfection of water systems is key when vulnerable individuals are present. Water safety plans are frequently designed to meet bottom-line directives rather than to reduce Legionella risks, and in some cases are not comprehensive enough to entirely avoid the growth of Legionella bacteria.
• Testing methods: Duty holders in healthcare facilities, hospitals and care homes are frequently advised to send samples of water to a lab. This is a well-known method for Legionella testing.

Managing the risk of Legionella in care homes and hospitals

As discussed earlier, Legionella kills approximately ten per cent of people who are infected. This number is, however, larger in high-risk scenarios like hospitals and healthcare facilities. According to official statistics, up to twenty-five per cent of people who get infected in facilities like hospitals or care homes will likely die.

Because of the high-risk nature of the care home and hospital sector, duty managers need to take all the necessary extra precautions against Legionella. Implementing a Legionella management plan is a very good place to start.

It is necessary to remove any areas of stagnation or dead legs from the water system. It is also necessary to establish temperature controls and make sure that the hot water is kept above sixty degrees and cold water below twenty degrees at all times. At such low temperatures, Legionella bacteria enter a low metabolic state, minimising and discouraging growth. If temperature control is not an option in the system, then duty managers need to ensure the regular use of biocides.

It is very important that these controls are tested periodically. The risk of acquiring Legionella can increase by sixty-four per cent for every sixty minutes spent near the source of the outbreak, and this number is higher for patients who are immunosuppressed. It is therefore key that duty managers in the healthcare sector can implement the necessary actions rapidly.