Legionnaires' disease is a severe form of pneumonia, with the severe lung inflammation usually caused by infection caused by the Legionella bacterium. This bacteria can cause serious respiratory illness such as Legionellosis, which is particularly harmful to the elderly, smokers and those with compromised immune systems.
While businesses in South Australia are being urged to check air conditioner systems, Flinders University researcher Dr Harriet Whiley feels more needs to be done, highlighting the high chance of false negative or false positive results in regular environmental sampling methods could potentially enable an outbreak.
“We shouldn’t rely on test results but instead focus on strict risk management strategies,” Dr Whiley says in a new research paper published in the International Journal of Environmental Research and Public Health.
Instead of testing for the bacteria, she believes the problem should be tackled from a different angle. “Given the bacteria is common in potable water, an alternative is to assume the pathogen’s presence and focus on the management of appropriate control measures and protecting high-risk populations,” she says.
Suggestions include maintaining temperature control and disinfection residuals, as well as preventing stagnant water or warm water causing significant biofilm formation. Additional control mechanisms, such as point-of-use water filters, are also recommended for those most at risk, such as transplant or intensive care patients.
Dr Whiley points out there is an increasing risk from this waterborne disease problem related to potable water distribution systems, many of which could contain dangerous pathogens.
“Any opportune pathogens such as these can cause an infection,” she says. “With estimates that the over 65s will exceed those less than 5 years old in the next few years, there will be a greater percentage of the population at a higher risk.” Dr Whiley believes we need to change the way we’re managing this now.
“Individuals can also take steps to protect themselves by making sure their household hot water system is set above 55C and to see a doctor if they experience any symptoms,” she adds.
The most common Legionella bacteria known to cause human disease are Legionella pneumophila and L. longbeachae. Between 5% and 15% of community-acquired pneumonia in Australia is linked to legionella infections.