Naegleria fowleri as a Water Pathogen
The tragic news, earlier this month, about a man who died in the United States from Naegleria fowleri, reminds us that despite this infection being rare, it is devastating and regular monitoring warm waters for contamination is critical.
The victim is suspected of contracting the infection, which is commonly referred to as a "brain-eating amoeba" after swimming in pool at a surf resort. The resort will remain closed during the investigation by health authorities.
Whilst this unfortunate incident might sound like something from a horror movie, there have been reports highlighting a lack of awareness of this contaminant, particularly in Australia's rural and remote regions.
What is Naegleria fowleri?
According to the New South Wales Ministry of Health, Naegleria fowleri is an amoeba (a microscopic free-living, single-celled, and naturally occurring organism). On rare occasions it can cause the onset of primary amoebic meningoencephalitis (PAM) that leads to the destruction of brain tissue and is almost always fatal. Its symptoms mimic those of bacterial meningitis and include fever, headache, nausea and vomiting.
Following the onset of symptoms, infection rapidly progresses, usually resulting in death within 5 days.
How do you get infected with Naegleria fowleri?
Authorities stress infection from Naegleria fowleri cannot occur from drinking, cooking or washing clothes in the water.[i] Rather, infection occurs when water containing the amoeba enters the body through the nose and then travels to infect the brain. This may occur from water-related activities in warm, untreated or poorly treated water when diving or swimming in pools, lakes, rivers and naturally occurring hot water, such as hot springs. In suburbia, the organism can be found in poorly maintained and under-chlorinated or unchlorinated swimming pools and in water discharged from industrial plants.
The Queensland Government has specified the ideal water temperature for this organism as being between 25°C and 40°C. Any water body that seasonally exceeds 30°C or continually exceeds 25 °C can also support the growth of Naegleria fowleri.
How water is protected
Public water supplies are generally chlorinated at levels high enough to protect against contamination. Here, each state and territory adhere to guidelines and extensive monitoring programs to ensure adequate disinfection and protection against such contamination as well as take precautions against other pathogenic microorganisms.
The Australian Drinking Water Guidelines provide information on the occurrence, detection and management of Naegleria fowleri. Of note, Chapter 10 provides information on monitoring for specific characteristics in drinking water. The Amoeba Response Protocol by the Government of Western Australia Department of Health also has useful information.
Challenges, however, may arise in plumbing systems where conditions are outside the control of utilities and where the water temperatures are high enough to support the growth of this organism.
In this situation, maintenance of water sources and regular sampling and analysis of warm waters is important in ensuring the effectiveness of risk control actions or commencing appropriate precautionary control measures.
Contact our team today to discuss your requirements.
- Amoeba Response Protocol by the Government of Western Australia Department of Health
- Australian Drinking Water Guidelines by the Australian Government
- Flyer on Free Living Protozoa (Naegleria Fowleri and Acanthamoeba)
- Water testing at Envirolab Services
References and Additional Reading
[i] C Nicholls, et al. (2016) Primary Amoebic Meningoencephalitis in North Queensland: The Paediatric Experience. Med J Aust 2016; 205(7): 325-328.