The Irukandji syndrome. A devastating syndrome caused by a north Australian jellyfish

The Irukandji syndrome is a group of delayed (10-40 mins, mean 30 mins) severe systemic symptoms occurring after an initial mild skin sting by small carybdeid (box) jellyfish including Carukia barnesi, known colloquially as the 'Irukandji'. Although the syndrome is well known in tropical Australian waters, the 1998-1999 season in north Queensland was notable for the unusually high number of victims with severe toxic heart failure who needed admission to intensive care facilities for more complex investigations and treatment. There have also been other severe and unusual symptoms reported this year, which leads to the conclusion that there may be more than one species of jellyfish causing the Irukandji syndrome, or a seasonal variation in the symptoms and/or severity of symptoms caused by Carukia spp.

This article describes the updated current state of information on the ecology of jellyfish causing the Irukandji syndrome, introduces the new symptoms, and discusses some treatment regimens that may be effective. Problems associated with inappropriate treatment are also discussed.

To date there have been no reported deaths from Irukandji envenomation but there have been a number of patients who were probably only saved by high quality intensive care treatment. Research into the cause and treatment of this potentially devastating syndrome is hampered by lack of funding, although there are large costs to the taxpayers for retrieval and medical treatment of victims. These costs are analysed and presented.