What is Legionnaires’ disease?
Legionnaire’s disease, also known as Legionellosis, is an environmentally acquired bacterial pneumonia with no person-to-person spread. It is caused by members of the genus Legionella, which are aquatic organisms and widely distributed in both natural and man-made habitats. In susceptible people, transmission of the disease may follow inhalation of contaminated water or dust aerosols. The most common species in Australia are Legionella Pneumophilia (found in water), and Legionella longbeachae (found in soil and potting mix).
Legionnaires’ disease in Australia
Legionnaires’ disease was first recognised after an outbreak of pneumonia in Philadelphia in 1976. The first Australian and New Zealand cases were described in 1978, and global efforts were soon undertaken to understand the spread and impact of Legionnaires’ disease around the world. As late as 2019, New Zealand was reported to have one of the highest Legionnaire’s disease rates in the world.
In 2002, the Australian Department of Health published A review of national legionellosis surveillance in Australia, 1991 to 2000. This study aimed ‘to analyse legionellosis notifications for the period 1991-2000 to establish the distribution of legionellosis in Australia with the aim of identifying risk factors amenable to public health intervention’.
Legionellosis is a notifiable disease under the public legislation of each Australian state and territory, and outbreaks must also be reported in New Zealand. Australian outbreaks have mostly been associated with exposure to aerosols from evaporative cooling towers, and complex domestic type water systems. Known sources of infective aerosols include evaporative cooling towers, shower heads, water taps, nebulisers and whirlpool spas, and other bodies of water.
What are the symptoms?
People with Legionnaires’ disease usually get sick between 2 and 10 days after being infected. The symptoms are similar to those of flu: headache, muscle pain, fever, body chills and a general feeling of being unwell. Within 2 or 3 days other symptoms may also develop, such as a cough which may bring up mucous or blood, shortness of breath, chest pain, nausea, vomiting and diarrhoea, confusion and/or other mental changes.
Legionnaires’ disease most often affects middle-aged and older people, particularly those who smoke or who have chronic lung disease. Also at increased risk are people whose immune systems are suppressed by medications and diseases such as cancer, kidney failure, diabetes or HIV. This leaves our elderly population particularly vulnerable to Legionella. While most people recover, Legionnaires’ disease can be fatal.
It is often difficult to distinguish Legionnaires’ disease from other types of pneumonia. Chest x-rays help diagnose pneumonia, but the diagnosis of Legionnaires’ disease requires special blood and urine tests to confirm the diagnosis. Fortunately, Legionnaires’ disease can usually be cured by treatment with antibiotics, and there are many antibiotics highly effective against Legionella bacteria.
While Legionnaires’ disease can be readily treated, prevention is the best cure, so testing for Legionella in water systems in health and aged care is mandatory. Premises with cooling water systems have responsibilities for ensuring these are maintained and operated in accordance with the Public Health Act 2010 and Public Health Regulation 2012.
When was the last time that your cooling systems were checked for Legionella? If you’re struggling to keep up with infection control requirements, contact Bug Control. We can help your aged care facility get their infection prevention and control back on track with checklists, audits, staff education resources, consultant access and more.