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Current Status of Knowledge and Action on Irukandji
Collated by CRC Reef on behalf of the Queensland Government Irukandji Jellyfish Response Taskforce Information
supplied by: 30 September 2002 Introduction and Background In response to this year's severe stinger season, and in particular, the fatalities of two international visitors from 'Irukandji Jellyfish Syndrome', Tourism Queensland coordinated the first meeting of a whole of State Government response to this issue on Wednesday 8th May 2002. This meeting discussed current marine stinger actions being undertaken by government agencies, community organisations (particularly Surf Life Saving Queensland) and operators, in the areas of community education, research and physical barriers. Due to the large number of stakeholders involved, it was agreed that there was a need to adopt a collaborative and coordinated approach to this issue amongst all stakeholders. These include all relevant Queensland Government agencies at all levels of Government (i.e. local, State and Commonwealth), research institutions, community organisations, regional tourism authorities and tourism operators in North Queensland. A Queensland Government Irukandji Jellyfish Response Taskforce was established to achieve this coordinated approach, along with two working groups - a Research Working Group and a Prevention and Response Working Group. Refer to Attachment A for a list of member organisations of the Taskforce and Working Groups. The first initiative of the Taskforce was to collate all available information on agreed current knowledge and preventative and response actions with regards to Irukandji Jellyfish Syndrome. CRC Reef agreed to coordinate this task, and this paper represents that collative exercise. This paper includes input from all experts in this area, and provides the basis upon which the future actions of the working groups will be developed. It is intended to be a working document, which will be updated as new knowledge becomes available and new issues arise. A Global Perspective Two deaths from jellyfish causing the irukandji syndrome in North Queensland during the 2001-02 summer have drawn disproportionate international attention. Potentially deadly jellyfish are not unique to North Queensland or northern Australia. Deaths from jellyfish occur regularly in other tropical countries but the deaths draw less media attention and the species responsible is often not identified. The
Cairns Experience 2001-2002 Responsible Jellyfish Irukandji syndrome is the name given to a group of systemic symptoms that occur after the sting of a jellyfish. Only one species, Carukia barnesi, has been demonstrated to cause the syndrome but unpublished studies implicate at least six different species, most of them as yet undescribed by scientists. Distribution and Abundance The distribution of Irukandji syndrome in Australia seems to be largely restricted to northern Australia between the Tropics of Cancer and Capricorn. On the east coast, it occasionally occurs as far south as Bundaberg. On the west coast, it is a significant problem for pearl divers based in Broome. Irukandji syndrome occurs most frequently in the Cairns - Port Douglas and Whitsunday regions. In the Cairns - Port Douglas region. about 50% of stings are recorded from inside the stinger resistant swimming enclosures ("stinger" nets) at Palm Cove and the other 50% are recorded from offshore and reef areas Collected specimens identifiable as Carukia barnesi have only been recorded from the immediate Cairns region and there is one report of it from Townsville offshore waters. In the 2001-02 summer they were collected primarily from Palm Cove, Trinity Beach and Fitzroy Island. Most cases of Irukandji syndrome occur between November and May ("the season") but cases have been recorded in every month of the year. Jellyfish causing Irukandji syndrome on the mainland (northern beaches of Cairns) usually occur for short periods of time (3-4 days) and usually only several times each season. They may, however, be present around reefs and offshore islands throughout the season. The occurrence of C.barnesi is highly variable from year to year. During 2000/01, 90 days of continuous sampling at Palm Cove caught 3 animals. Similar sampling in 2001/02 caught over 300 animals in 2 days. The origin of C.barnesi that appear on the mainland beaches is unknown. C. barnesi is most abundant after N/E winds in the Cairns area. Information on Irukandji appearance has not been determined in other areas to date. General Biology The cubozoans (Class Cubozoa) or box jellyfish are the most dangerous group of jellyfish and have caused hundreds, possibly thousands of human deaths in tropical and sub-tropical waters world-wide. There are two families of cubozoans, the chirodropids (including Chironex fleckeri or box jellyfish) and the carybdeids (including the Irukandji jellyfish). The carybdeids generally have only one tentacle arising from each corner of the bell, the chirodropids have many tentacles in each corner. Carybdeids are usually smaller than chirodropids, although very large ones do occur worldwide. C.barnesi only grows to about 25mm across the bell while Chironex fleckeri can grow to 350mm across the bell. Most research to date has been carried out on chirodropids, in particular Chironex and Chiropsalmus spp., rather than carybdeids. Life History and Behaviour The life history of C.barnesi and other Australian Irukandji stingers is unknown. The lifecycle for carybdeid box jellyfish is only known for Carybdea alata from Hawaii and Puerto Rico and Tripedalia cystophora from the northern hemisphere. For these animals, juveniles or polyps are thought to live on coral reefs. In offshore waters around coral reefs, box jellyfish that cause Irukandji syndrome are usually well dispersed and the incidence of stings is very small. However, when they move inshore, probably carried by currents, they become concentrated at the waters edge. At certain times of the year (usually 8-10 days after a full moon), spawning aggregations may also occur on offshore reefs. Some box jellyfish that cause Irukandji syndrome are attracted to lights and night divers on the reef are occasionally stung. Irukandji Syndrome Classic
Irukandji Syndrome is one of a collection of systemic symptoms and signs
occurring after: The
"Classic" syndrome is: Signs
of Irukandji syndrome are: The period of distressing features of Irukandji syndrome is variable, from a few hours to several days. Since 1983 there have been 11 published reports of reversible cardiac failure occurring in patients who have experienced classic Irukandji syndrome. The cause of the cardiac failure is open to debate with opinions varying from the effects of a direct cardiac toxin to catecholamine induced cardiac failure. There have been two recent deaths (2002) following the development of classic Irukandji syndrome. The first occurred near Hamilton Island in the Whitsunday Islands and the second at Opal Reef off Port Douglas. Location of stings on the body Unlike Chironex stings, which occur mainly on a victim's legs in shallow water, most Carukia stings occur in deeper water (>1m) and on the victim's body just below the surface. Thus Carukia stings are usually on the trunk or upper arms of swimmers, or on the back (or back of neck if a wetsuit is worn) in surfacing divers. Treatment First Aid Ensure safety of first aid provider then remove victim from danger. Check for conscious level and assess airway, breathing, circulation as per Australian Resuscitation Council's recommendations; resuscitate if required. Restrain victim or others from rubbing the sting. The sting site should be doused liberally with vinegar. This will ensure that any undischarged nematocysts are made inactive and unable to fire. Vinegar does not alter the venom in any way and must not be considered an antidote.
Medical management To date the mainstay of medical treatment of Irukandji syndrome is the control of symptoms being experienced and observing and investigating for possible complications. A cornerstone of the management is that of adequate pain relief through the aggressive use of intravenous pain-killers. Historically pethidine has been advocated as the analgesic of choice although anecdotal experience is moving towards morphine or fentanyl. There is no trial that demonstrates superiority of one over the other although theoretical reasons may infuence the choice. The large amounts of analgesic requirements may encroach on the safe dosage of pethidine (given its known neurotoxicity in large doses). Similarly the prolonged sedative and dysphoric effects of morphine may sway the choice towards fentanyl. Overall there is no proven superiority of one over the other. No other medication has yet been tested for pain relief, although this area needs research. The use of anti-histamines as an adjunct to analgesia is unclear. Their utilisation has reduced the amount of analgesic required in one trial. However, the addition of a medication with a significant risk of side effects needs to be balanced against the risk of opiate toxicity. The utilisation of catecholamine antagonists such as a- blockers , has proven effective in the Mackay region. The use of b-blockers is controversial with severe renal shutdown occurring in one published case. Although there is growing consensus that b-Blockers should be avoided there is no absolute consensus as to whether a-Blockers may be of benefit. There are no antivenoms to the Irukandji toxins and antidotes are of questionable benefit. Prevention Beach Closure Surf Life Saving Queensland has developed an advanced draft Best Practice Guidelines for Marine Stinger (Risk Management). Drag netting trials show a close relationship between stings occurring and jellyfish being caught. As a result Surf Lifesaving Queensland (SLSQ) has recently developed and implemented a new policy for Irukandji stings. The beach is now closed anytime a researcher nets an Irukandji, regardless of a sting or not. Additionally, the beach is closed immediately after the first sting is confirmed. The beach (enclosure) remains closed until a change of tide and weather pattern occurs and/or net drags are carried out and no jellyfish are collected. Further, a warning sign may be used alongside the yellow warning flag suggesting days when the presence of Irukandji may be higher than normal. This will be after 2 days of northerly / north-easterly winds together with an afternoon high tide. This new policy will hopefully help reduce the number of Irukandji sting cases in Queensland where Surf Life Saving Queensland lifesavers or lifeguards patrol the beach: the previous SLSQ policy was 2 confirmed Irukandji stings before the lifeguard closed the beach. Yellow flags are currently flown at all times on Queensland patrolled beaches. Signs are used to advise of possible further risk factors (e,g, presence of Irukandji jellyfish). Barrier Nets There are currently 20 "stinger nets" in north Queensland, designed and sold by Uninet. They have a mesh size of 25mm and are designed to exclude large box jellyfish and large segments of box jellyfish tentacles and in the right locations are very effective at doing this. They do not exclude small segments of box jellyfish or Carukia barnesi. The nets work well on beaches with moderate tidal ranges but are not appropriate in areas of large tidal range such as in the Mackay Region, or those with fast currents, as in the Whitsunday Islands. Tests of a finer, 8mm mesh net were carried out in 1990 but were unsuccessful. Issues with the finer mesh nets include fouling and increased resistance to waves and currents that can cause the nets to lift and let animals, including box jellyfish, inside the net. Further trials are underway in Cairns using a shade cloth mesh together with the normal mesh. Stinger Suits Lycra "Stinger" suits provide protection against irukandji stings provided that undue pressure is not applied. For example sitting on a jellyfish while wearing a suit could lead to a sting. Bathers wearing stinger suits are still vulnerable to unprotected areas such as feet, hands, neck and face. Topical Creams Compounds have been isolated that may, one day, be able to be used for some form of protection from stinging jellyfish, including being added to ultra-violet protection creams. Community/visitor education On behalf of the Prevention and Response Working Group, Surf Life Saving Queensland is coordinating the development of a range of visitor, community and tourism industry education materials and initiatives. Together with Surf Life Saving Queensland, Tourism Queensland and the Regional Tourist Organisations will be responsible for disseminating this information to visitors and tourism operators, and Queensland Health and Local Governments will be responsible for disseminating the information to the local communities Toxinology Mode of Delivery Venom
is delivered by nematocysts which in Carukia barnesi occur on both the
bell (body) and the tentacles. A single jellyfish can have a number
of different kinds of nematocysts used for different purposes. Tentacles
can be different lengths and shapes and nematocysts on tentacles can
be uniformly distributed along the tentacle or aggregated (eg pearl-like
strings of nematocysts on C.barnesi) The toxins involved in causing Irukandji syndrome are unknown. At least 20 different types of proteins are present in C.barnesi venom. Effects of Toxins Preliminary, published, laboratory studies using crude venom extract (from squashed whole animals) suggest that C.barnesi venom acts as a presynaptic neuronal sodium agonist. Similar tests also suggest that C.barnesi venom powerfully stimulates noradrenaline release. Response of Tourism Industry Tourism
operators in North Queensland have contributed to the prevention of
marine stings, in the past, by distributing educational information
to visitors in the form of brochures and fact sheets. However, following
the severe stinger season of 2001/02 many operators ceased distributing
this information for fear that it was potentially inaccurate and out
of date. Also, the brochure previously produced by the Queensland Tropical
Health Unit was reported to be 'out of print', therefore tourism operators
report and that they have had no updated information to distribute for
some time. Irukandji Websites: http://www.reef.crc.org.au/aboutreef/coastal/irukandji.html
This collation was put together by Dr David Williams with major assistance from Dr Peter Fenner, Dr Peter Pereira Dr Jamie Seymour and Prof Bob Porter
For further information on this paper please contact: Chair,
Queensland Government Irukandji Jellyfish Research Working Group Chair,
Queensland Government Irukandji Jellyfish Prevention and Response Working
Group ATTACHMENT A: Queensland Government Irukandji Jellyfish Taskforce andWorking Groups membership
·
Tourism Queensland (lead agency) Queensland Government Irukandji Jellyfish Prevention and Response Working Group ·
Queensland Health (lead agency) Queensland Government Irukandji Jellyfish Research Working Group ·
CRC Reef (lead agency)
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