Scientists and community leaders in Western Australia are concerned rising temperatures will cause more freshwater pools to harbour brain-eating amoebas.
Key points:
- Two freshwater pools have been closed in WA's South West after Naegleria fowleri was detected
- Naegleria fowleri can cause a rare brain-eating infection called amoebic meningitis
- Water scientist Richard Theobold says as the climate gets hotter, more amoebas could be found in fresh water
The Shire of Harvey in the state's South West has warned people not to swim in Brunswick Pool — a popular freshwater swimming spot — after Naegleria fowleri was detected during a routine water quality test.
If water containing Naegleria fowleri, commonly known as the "brain eating amoeba", is inhaled through a person's nose, it can cause a rare infection known as amoebic meningitis.
While the risk of catching amoebic meningitis is low, the infection is usually fatal.
The Shire of Waroona also closed Drakesbrook Weir to swimming, as it conducts further testing to determine if an amoeba identified during a routine water quality check is Naegleria fowler.
Shire president Mike Walmsley said the recent hot temperatures meant the amoebas were thriving and he did not remember having to close the weir so early in summer.
"That's a concern, certainly. But given that it's sort of been warm, right through December and January, I guess it's to be expected," Mr Walmsley said.
Hotter temps could mean greater risk
Mr Walmsley said he was concerned amoebas would be detected more frequently as temperatures rose.
"Personally, it feels like the hottest summer we've had for some time … Perhaps the sustained heat has really ramped up this particular year," he said.
WA Health Department water scientist Richard Theobold said a growing number of freshwater pools might harbour deadly naturally occurring amoebas as the climate got hotter.
"As the temperatures rise, you'll find that natural water bodies will increase in temperature … so, more areas that are nice and warm and fresh, it's more likely you'll get Naegleria and Naegleria fowleri," he said.
Mr Theobold said nothing could be done to prevent amoebas growing in natural waters, but people could take steps to prevent harm.
"Every year we put out amoeba warnings to the community, reminding them to make sure that they properly chlorinate their pools, empty their wading pools after every use, and treat any natural water body with caution," he said.
"As an individual, you certainly can be careful by not doing a 'bommie' into the water or any form of activity that would force the water up in through your nose."
Mr Theobold said while there had not been an infection in WA since the 1960s, people needed to heed warning signs and take caution when swimming in fresh water.
"The problem is that while the actual rate is very low, the outcome is very poor, it is almost certain death. So you just don't want to have an infection at all," he said.
Mr Walmsley said while the Drakesbrook Weir was closed to swimming, he still encouraged people to visit the area.
"It's kind of sad at the moment that we have to close it for swimming … but there's still barbecue facilities and it's still not a nice spot on a cool evening," he said.
"[People] need to be really careful with the little ones, I would think that adults are probably wise enough to know not to put your head under, but especially with children, it's probably going to be really hard to control that or to explain."