The Dangers of a Jellyfish Sting & What You Need to Know

Carukia barnesi, a tiny jellyfish measuring the size of a thumbnail, is the only jellyfish proven to cause irukandji syndrome.

An American tourist, Robert King, died after being stung by a jellyfish while snorkeling off Australia's northeast coast on the Great Barrier Reef. King is believed to have developed irukandji syndrome from the sting, causing a rapid rise in blood pressure and a cerebral hemorrhage.

Just three months earlier, British tourist Richard Jordan became the first person on record in Australia to die from irukandji syndrome after he was stung.

The Jellyfish and Irukandji Sydrome
Carukia barnesi, a tiny jellyfish measuring the size of a thumbnail, is the only jellyfish proven to cause irukandji syndrome. However, it is now believed that a sting from at least six different species of jellyfish can produce the same symptoms which include lower back pain, muscle cramps, vomiting, restlessness and anxiety. In rare cases, the victim can suffer pulmonary oedema (fluid on the lungs) or cardiac problems that could be fatal if not treated.

The larger box jellyfish Chironex fleckeri are found in tropical waters from Exmouth in Western Australia to Agnes Water (near Gladstone) in Queensland. Carukia barnesi has only been collected close to Cairns in north Queensland, but some of the species that cause irukandji syndrome are found regularly as far south as Great Keppel Island, or less frequently as far south as Bundaberg.

Each year, varying numbers of people are stung - from only a few to more than 200 people. In the summer of 2001-2002, approximately 160 people were stung by mid February. Most at risk are snorkelers and divers.

The initial sting of the jellyfish is usually not very painful. But about 5-45 (usually 30) minutes after being stung, the person starts to have a severe backache or headache and shooting pains in their muscles, chest and abdomen. They may also feel nauseous, anxious, restless and vomit. In rare cases, the victim suffers pulmonary oedema (fluid on the lungs) which could be fatal if not treated.

Treatment
The sting should be flushed with vinegar and the patient taken to hospital as soon as possible if they develop irukandji syndrome to be treated for the pain.

Prevention
The mesh used in stinger-resistant nets in north Queensland is broad enough to kept out the box jellyfish Chironex fleckeri but allows the small thumnail-sized C. barnesi to pass through.

A lycra body suit can help protect against stings although people can be stung where the suit does not cover the skin - around the feet, neck and head.

(Sources: CRC Reef Research Centre, Associated Press, Dept. of Pharmacology Research at University of Melbourne)