Irukandji most venomous but box jellyfish kills faster
WITH venom 100 times more potent than a cobra and 1000 times more potent than a tarantula, the irukandji jellyfish is believed to be the most venomous creature in the world.
Six people, including three children, have been hospitalised since the New Year after being stung by irukandji off Fraser Island.
It's a highly unusual situation and, according to experts, very unlikely to happen in Keppel Bay.
Despite the cluster of stings, experts say most people wouldn't die from an irukandji sting and the box jelly fish remains a much greater threat.
Dr Lisa-ann Gershwin, director of the Australian Marine Stinger Advisory Service and Australia's only dedicated box jellyfish expert, said the chances of being stung by irukandji were low.
"The box jellyfish is a much bigger threat," she said.
In 1957, a 10-year-old boy was fatally stung by a box jellyfish off Bluff Beach, Yeppoon, and 30 years later a five-year-old boy died after being stung off Gladstone.
There has been no fatality from an irukandji in Central Queensland waters and although the chances are very small, Dr Gershwin said she would always wear a stinger suit if she was in Keppel Bay during stinger season.
"The most likely thing at Fraser Island is a body of water has blown in from somewhere else … as soon as weather changes it will blow out again.
"I haven't been up to Fraser to take samples. It's an educated guess, but that is what makes the most sense.
"There's no increase in numbers. It's just completely unusual," she said.
Every summer more than 60 people are hospitalised with irukandji syndrome, but unlike the box jellyfish, which can cause death in a healthy adult in minutes, the irukandji can take days before its effects are fully felt.
The initial sting is typically mild, followed by vomiting, profuse sweating, headache, agitation, rapid heart rate and high blood pressure.
The increase in blood pressure may be life-threatening and can be associated with abnormal heart beat and heart failure.
Dr Michael Corkeron, of the Townsville Hospital Intensive Care Unit, successfully treated patients stung by irukandji with magnesium infusions, delivered by intravenous drip.
"The remarkable thing is that magnesium infusion is a long-established, very safe and inexpensive treatment," Dr Corkeron said.
Dr Gershwin said the treatment was absolutely remarkable, though not suited to every species.
Time to death, the box jelly beats everything hands down
"For the more severe, it's almost magic," she said. "This treatment is a miracle indeed ... it stops the syndrome in its tracks, just like that … boom, it stops the pain, everything."
As yet, scientists don't know where the irukandji live most of the time, or where they breed.
"No reports of finding breeding sites have turned out to be true," Dr Gershwin said.
"Irukandji are more like orchids than cane toads.
"They're very delicate with very specific requirements, so in order to thrive in a different area, they would need their whole habitat to migrate with them."
A much greater problem is the better known and much more dangerous box jellyfish.
Australia has only had two confirmed deaths from irukandji and though the real figure could be higher, there have been 71 cases of death from box jellyfish sting.
"Time to death, the box jelly beats everything hands down," Dr Gershwin said.
"I swim in Keppel Bay every year … there is only a slim chance of running into a box jellyfish there, but I wouldn't swim unprotected in that area."
Dr Gershwin recommended a full-body lycra stinger suit which fitted snug against the skin.
"And look out for clusters of what looks like crushed glass or ice at the high tide line … they're salps or weird jellyfish creatures that hang out with irukandji.
"If you see that on the beach, that's the highest risk factor we know," she said.