TOWNSVILLE, Australia (AP)--An American tourist was in a critical condition Tuesday after being stung by a peanut-sized jellyfish while swimming off Australia's northeast coast, a hospital spokeswoman said.

The 44-year-old man was stung by an irukandji jellyfish while swimming on Great Barrier Reef. His identity was not immediately released.

He was airlifted to Townsville Hospital from Cairns, 400 kilometers (249 miles) to the north, on Saturday night after he was classified as a neurological emergency, a hospital spokeswoman said on customary condition of anonymity.

Earlier this year, British tourist Richard Jordan became the first person on record to die from an irukandji sting.

The American was one of at least 20 people stung by irukandji or box jellyfish over the weekend.

Beaches in northeastern Australia were infested with huge numbers of irukandji in December and January. At least 79 people were hospitalized after being stung.

Stings can bring on irukandji syndrome, which causes intense aches all over the body, cramps that are compared with birth pains, nausea, vomiting, fever and anxiety.

James Cook University jellyfish expert Jamie Seymour said there had also been an unusually high number of the toxic box jellyfish in north Queensland waters at the weekend.