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We present here the first reported case of mid-ventricular stress cardiomyopathy secondary to 'Irukandji syndrome', following envenomisation from a jellyfish. Carukia barnesi is a cubozoan or box jellyfish found in Far North Queensland, Australia prevalent during the warmer months of the year. It has been associated with 'Irukandji syndrome' as characterized by a sympathetic overdrive secondary to an excess of endogenous catecholamines release. There have been previous cases of sudden onset of left ventricular dysfunction and jellyfish. The author believes that this case is important because it highlights the possible association between the sudden release in catecholamines and stress cardiomyopathy.

We have previously characterised the pharmacological activity of a number of jellyfish venoms with a particular emphasis on the profound cardiovascular effects. It has been suggested that jellyfish venoms are difficult to work with and are sensitive to pH, temperature and chemical changes. The current study aimed to examine the working parameters of the venom of the Australian box jellyfish Chironex fleckeri to enable fractionation and isolation of the toxins with cardiovascular activity. C. fleckeri venom was made up fresh each day and subjected to a number of different environments (i.e. a pH range of 5-9 and a temperature range of 4-30 degrees C). In addition, the effect of freeze drying and reconstituting the venom was investigated. Venom (50 microg/kg, i.v.) produced a transient hypertensive response followed by cardiovascular collapse in anaesthetised rats. This biphasic response was not significantly effected by preparation of the venom at a pH of 5, 7 or 9. Similarly, venom (50 microg/kg, i.v.) did not display a loss of activity when exposed to temperatures of 4, 20 or 30 degrees C for 1.5h. However, the cardiovascular activity was abolished by boiling the venom. Freeze drying, and then reconstituting, the venom did not significantly affect its cardiovascular activity. However, repeated freeze drying and reconstituting of extracted venom resulted in a significantly loss of activity. This study provides a more detailed knowledge of the parameters in which C. fleckeri venom can be used and, while supporting some previous studies, contradicts some of the perceived problems of working with the venom.

Clinical observations suggest a primary cardiotoxic role in fatal Chironex fleckeri stings. The limited research available indicates that Chiropsella bronzie venom acts in a similar manner although appears to be less potent. The aim of the present study was to elucidate the vascular effects of C. fleckeri and C. bronzie venoms using rat isolated aorta. Both venoms produced a sustained contraction of endothelium-denuded aorta which was not significantly affected by prazosin or box jellyfish antivenom. Felodipine significantly reduced the contractile response to C. fleckeri venom but not C. bronzie venom. Both venoms produced an initial relaxation (Phase 1), followed by a sustained contraction (Phase 2), in pre-contracted endothelium-intact aorta. Removal of the endothelium significantly inhibited both phases of the response. NOLA significantly inhibited Phase 1, but not Phase 2, of the response to both venoms. Atropine, HOE 140 or BQ 123 did not have any significant inhibitory effect on either phase. In conclusion, neither C. fleckeri nor C. bronzie venoms appear to contain components with activity at alpha(1)-adrenoceptors. Antivenom was ineffective in reversing the effects of the venom suggesting it is incapable of completely neutralising nematocyst-derived venom. Determining the mechanism of action of these venoms will allow for the development of better treatment strategies.

Dr Jack Handyside Barnes (1922-1985) was one of the small and elite group of Pacific marine toxinologists whose work was characterised by an uncompromising rugged persona, a focussed resolve to solve challenging problems of human clinical envenomation, and who conducted curiosity-driven research under conditions of scientific isolation. He was a pioneering advocate for the preservation of marine heritage, particularly that of the Great Barrier Reef. A former military commando who later became a general medical practitioner with extensive surgical and obstetric skills, in 1947 he was appointed the Medical Superintendent of Thursday Island in the Torres Strait. Later (from January 1953), he worked indefatigably as a general medical practitioner in Cairns, in tropical North Australia. For four decades (1945-1985), Jack Barnes undertook detailed laboratory, clinical and field research into invertebrate envenomation, particularly medusan toxinology. In 1960 he discovered the species responsible for the Irukandji syndrome, a small carybdeid named Carukia barnesi in his honour. He invented the research technique for the extraction of venom from the world's most venomous creature, the Pacific box Jellyfish, Chironex fleckeri. By 1960, he had published taxonomic details of nematocyst structure and clinical envenomation details consequent upon stings by Physalia, Cyanea, Chironex, Chiropsalmus and Carukia. This paper is a précis of the chronology of his life, contributions and influence.

The Irukandji syndrome is a jellyfish envenomation caused by Carukia barnesi or related jellyfish. In literature, the distribution of "Irukandji-like" syndromes is restricted to Australia. We report a case of probable Irukandji syndrome in Thailand. With this report, we hope to promote awareness to aid sting prevention and stimulate research.

Background: Jellyfish stings are a common occurrence among ocean goers worldwide with an estimated 150 million envenomations annually. Fatalities and hospitalizations occur annually, particularly in the Indo-Pacific regions. A new topical jellyfish sting inhibitor based on the mucous coating of the clown fish prevents 85% of jellyfish stings in laboratory settings. The field effectiveness is unknown. The objective is to evaluate the field efficacy of the jellyfish sting inhibitor, Safe Sea., Methods: A double-blind, randomized, placebo-controlled trial occurred at the Dry Tortugas National Park, FL, USA and Sapodilla Cayes, Belize. Participants were healthy volunteers planning to snorkel for 30 to 45 minutes. Ten minutes prior to swimming, each participant was directly observed applying a blinded sample of Safe Sea (Nidaria Technology Ltd, Jordan Valley, Israel) to one side of their body and a blinded sample of Coppertone (Schering-Plough, Kenilworth, NJ, USA) to the contralateral side as placebo control. Masked 26 g samples of both Safe Sea SPF15 and Coppertone SPF15 were provided in identical containers to achieve 2 mg/cm(2) coverage. Sides were randomly chosen by participants. The incidence of jellyfish stings was the main outcome measure. This was assessed by participant interview and examination as subjects exited the water., Results: A total of 82 observed water exposures occurred. Thirteen jellyfish stings occurred during the study period for a 16% incidence. Eleven jellyfish stings occurred with placebo, two with the sting inhibitor, resulting in a relative risk reduction of 82% (95% confidence interval: 21%-96%; p= 0.02). No seabather's eruption or side effects occurred., Conclusions: Safe Sea is a topical barrier cream effective at preventing >80% jellyfish stings under real-world conditions.

Irukandji Syndrome can be frightening for the patient and make care delivery difficult for the nurse. Nurses' knowledge of Irukandji Syndrome has been limited to information provided by marine biologists, doctors, and tropical medicine specialists. This paper proposes to assist with the evolution of nursing knowledge for the care of the patient with Irukandji Syndrome. An algorithm of nursing management is presented that has been derived from the continuing debate among scientists about the etiology of signs, symptoms, and treatment rationales. Community safety and education surrounding Irukandji Syndrome requires concurrent progression of nursing knowledge and scientific inquiry.

This paper describes one neurotoxin and three cytolysins isolated from the venom of the Caribbean box jellyfish Carybdea marsupialis. To assess the cytolytic and neurotoxic activity of the nematocyst venom, several bioassays were carried out, and to evaluate the effect of the toxin, the dose causing 50% lethality (LD(50)) was determined in vivo using sea crabs (Ocypode quadrata). The proteins with neurotoxic and cytolytic effects were isolated using low-pressure liquid chromatography. The fraction containing the neurotoxic activity was analyzed by SDS-PAGE and showed a single protein band with an apparent molecular weight of 120 kDa (CmNt). To demonstrate the neurotoxic activity of this protein, a small fraction of the purified protein was injected into a crab, and the typical convulsions, paralysis, and death provoked by neurotoxins were observed. Three fractions containing cytolysins had protein bands in SDS PAGE with apparent molecular weights of 220, 139, and 36 kDa, and their cytolytic activity was confirmed with the haemolysis assay.

Objective: To describe the epidemiology and clinical features of box jellyfish envenoming in the Top End of the Northern Territory and, in particular, confirmed stings from the major Australian box jellyfish, Chironex fleckeri., Design: Prospective collection of clinical data and skin scrapings or sticky-tape tests for nematocyst identification from patients presenting to Royal Darwin Hospital and remote coastal community health clinics in the Northern Territory, spanning 10 950 km of coastline; analysis of tidal, weather and seasonal data., Patients: All patients with jellyfish sting details recorded between 1 April 1991 and 30 May 2004., Main Outcome Measures: Demographic and clinical features, use of C. fleckeri antivenom, and associations between weather, seasonal and tidal factors and confirmed C. fleckeri stings., Results: Of 606 jellyfish stings documented, 225 were confirmed to have been caused by C. fleckeri. 37% of C. fleckeri stings were in children, 92% occurred during the "stinger season" (1 October to 1 June), 83% occurred in water 1 m or less deep, and 17% occurred while victims were entering the water. Stings were least common on outgoing tides (P < 0.001) and commonest between 15:00 and 18:00 (P < 0.001) and on days with wind speed less than that month's average (P < 0.001). Nearly all victims experienced immediate pain, but this could often be controlled with ice; only 30% required parenteral narcotics and 8% required hospital admission. Cardiorespiratory arrest occurred within several minutes of the sting in the one fatal case, involving a 3-year-old girl with only 1.2 m of visible tentacle contact. C. fleckeri antivenom was given to another 21 patients, none of whom had life-threatening features at the time they were given antivenom., Conclusions: Most C. fleckeri stings are not life-threatening; patients who die usually have cardiopulmonary arrest within minutes of the sting. The potential benefit of antivenom and magnesium under these circumstances remains to be shown, but a protocol with their rapid use is recommended if cardiopulmonary arrest has occurred. Unfortunately, this is unrealistic for many rural coastal locations, and the priority remains prevention of stings by keeping people, especially children, out of the sea during the stinger season.

Introduction: Irukandji syndrome, a potentially life-threatening condition that follows the sting of small carybdeid jellyfish, occurs along the northern Australian coastline from Broome, Western Australia in the west to Rockhampton, Queensland in the east. Much of this area is classified rural or remote. Because correct patient management is essential to avoid unnecessary fatality, and stings are relatively uncommon in any specific location, it was considered important to document current approaches to Irukandji syndrome management throughout coastal northern Australia, comparing urban and more rural health facilities, and to assess the availability of management guidelines for health staff., Methods: A telephone survey of the clinicians responsible for Irukandji syndrome patient management at 34 coastal northern Australian health facilities that might encounter this patient presentation was conducted during November and December 2003. Healthcare providers responsible for Irukandji syndrome management on the day of survey were interviewed using a structured, standardized questionnaire, which included a description of a hypothetical patient with Irukandji syndrome. This was used to stimulate a spontaneous description of the usual response of the particular health facility to such a patient presentation. Additional vignettes were used to investigate further specific aspects of patient management, including first aid, and pain and blood pressure management. Respondents were also asked about the existence of Irukandji treatment guidelines at their facility., Results: All 34 facilities contacted agreed to participate. Five health facilities were in urban centres with a population of 50,000 or greater, four were within 50 km of such centres, 20 were more remote and five facilities were on islands. Basic clinical monitoring (blood pressure, pulse, respiratory rate and oxygen saturation) was generally adequately practised. Topical application of vinegar as a first aid measure was described by 79% of respondents, with spontaneous mention of vinegar significantly associated with increasing remoteness (p = 0.023). Other sting site management was variable, with uncertainty about the use of pressure immobilisation bandaging. Intravenous opiate analgesia was administered at 91% of facilities, and magnesium sulphate, a treatment that is still being evaluated for its role in Irukandji syndrome-related pain and hypertension, was mentioned by 12% of respondents for pain relief. Twelve different pharmacological treatments were used for syndrome-associated hypertension, with magnesium sulphate being mentioned by 21% of respondents. Of the 22 facilities with guidelines, 14 used either the Primary Clinical Care Manual or the Central Australian Rural Practitioners Association Standard Treatment Manual. The remaining guidelines were independently produced protocols. The availability of guidelines was associated with appropriate use of intravenous opiate for adequate pain relief (p = 0.037). Although all urban health centres and 75% of health facilities <50 km away had guidelines, only 56% of more remote or island facilities reported the availability of guidelines., Conclusions: Although monitoring and pain management of patients with Irukandji syndrome were generally appropriate, a variety of inappropriate first aid and hypertension management approaches were found. In general, appropriate practice was associated with the presence of guidelines but, unfortunately, guidelines were less often present in remote health facilities. This is particularly important because the majority of respondents who reported no experience of managing Irukandji syndrome were located in more remote settings. There is a need for uniform, evidence-based guidelines, and mechanisms for effective dissemination of these guidelines with training for all health staff who may be required to manage Irukandji syndrome, particularly in remote areas of northern Australia.

This is a review of Medline and PubMed articles on venomous animal bites and stings during pregnancy reported in English literature from 1966 to 2002. Eighty-five venomous snakebites were reported in pregnant women. Although there are frequent anecdotal reports of scorpion stings in pregnant women, few case reports are documented. Other venomous animal bites or stings to pregnant women that have been reported include spiders, jellyfish, and insects, and these are described. Adverse reproductive and teratogenic effects of venoms on gravid animals are also briefly reviewed. Although uncommon, venomous bites and stings during pregnancy may have significant adverse effects on the fetus and the mother.

Objective: To evaluate the protective effects of a jellyfish sting inhibitor formulated in sunscreen lotion vs conventional sunscreen against Chrysaora fuscescens and Chiropsalmus quadrumanus jellyfish., Methods: Twenty-four healthy subjects at 2 research sites were randomly assigned to receive the jellyfish sting inhibitor (Nidaria Technology Ltd, Jordan Valley, Israel) to one forearm and conventional sunscreen to the other arm in a blinded fashion. Subjects were stung with jellyfish tentacles on each forearm for up to 60 seconds. Erythema and pain were assessed at 15-minute intervals over a 2-hour period., Results: In the C. fuscescens group, all 12 arms pretreated with conventional sunscreen demonstrated erythema, and all subjects noted subjective discomfort. In contrast, no arm pretreated with the jellyfish sting inhibitor had objective skin changes (P < .01). Two subjects noted minimal discomfort in the arm treated with the sting inhibitor (P < .01). In the C. quadrumanus group, discomfort was reported in 3 of the 12 inhibitor-treated arms compared with 10 of the 12 placebo-treated arms (P < .05). Erythema was noted on 1 arm treated with the inhibitor and 9 arms treated with the placebo (P < .01)., Conclusions: The jellyfish sting inhibitor prevented sting symptoms of C. fuscescens jellyfish in 10 of 12 subjects and diminished the pain of the jellyfish sting in the remaining 2 subjects. The jellyfish sting inhibitor also inhibited the more severe sting of the C. quadrumanus jellyfish in the majority of subjects. The jellyfish sting inhibitor does not eliminate the sting from C. fuscescens or C. quadrumanus jellyfish but significantly reduces the frequency and severity of stings.

Using a new technique to extract venom from the nematocysts, the efficacy of CSL box jellyfish antivenom (AV) and adjunct therapies, verapamil and magnesium sulfate (MgSO(4)), were investigated against the in vivo cardiovascular effects of Chironex fleckeri venom in anaesthetised rats. C. fleckeri venom (30 microg/kg; i.v.) produced a transient hypertensive response followed by hypotension and cardiovascular collapse within 4 min of administration. Prophylactic treatment of anaesthetised rats with CSL box jellyfish AV (3000 U/kg; i.v.) did not have any effect on the venom-induced pressor response, but prevented cardiovascular collapse in four out of 10 animals. Administration of verapamil (20mM@0.25 ml/min; i.v.) either alone or in combination with AV, did not have any effect on the C. fleckeri venom-induced pressor response nor the consequent hypotension or cardiovascular collapse of animals. However, the administration of verapamil negated the partially protective effects of AV. Concurrent artificial respiration of animals with the above treatments did not attenuate the C. fleckeri venom-induced cardiovascular effects. MgSO(4) (0.05-0.07M@0.25 ml/min; i.v.) alone did not have any effect on the venom-induced pressor response nor the consequent cardiovascular collapse of animals. However, although combined AV and MgSO(4) administration could not inhibit the transient pressor effect following the administration of C. fleckeri venom, it prevented cardiovascular collapse in all animals. We show for the first time, the cardiovascular effects of a C. fleckeri venom sample free of tentacular contamination and the potential of MgSO(4) as an adjunct therapy for the treatment of potentially fatal C. fleckeri envenomings.

Objective: To determine the knowledge, beliefs, and behavior of local residents and visitors to North Queensland who may be at risk of contact with "Irukandji" jellyfish., Methods: Structured interviews were conducted with 208 ferry passengers (92.9% response) traveling between Magnetic Island and Townsville (19 degrees S)., Results: A total of 88.1% of the locals, 69.8% of the domestic tourists, and 34% of the international tourists knew what an Irukandji was (P < .001). Half of the international tourists, 20% of the domestic tourists, and 3.9% of the locals with this knowledge incorrectly assumed it was safe to swim inside stinger-resistant enclosures or were unsure (P < .001). Visitors to Magnetic Island who had swum or intended to swim in the sea (47%) knew less about Irukandji than other visitors (P = .05). Only 42.3% of the respondents realized that Irukandji posed a risk to swimmers on the outer reefs, and only 33.1% knew that Irukandji were also found outside North Queensland., Conclusions: International tourists had little knowledge about Irukandji. Thus, accurate educational messages may need to be targeted at this group. Offshore water sport and reef tour operators should be encouraged to provide clients with protective clothing to minimize the risk of stings. A coordinated educational response across northern Australia may be necessary to inform the public about both the box jellyfish (Chironex fleckeri) and Irukandji.

Irukandji syndrome is a constellation of delayed severe local and systemic symptoms occurring after a Carukia barnesi box jellyfish sting involving any exposed skin. These cases are limited to Australia, the habitat of that animal. Numerous other cases of an Irukandji-like syndrome after other small Carybdeid genus envenomations have been reported elsewhere in the world. There have yet been no reports of Irukandji-like syndrome occurring in continental US coastal waters. We describe 3 cases of marine envenomation causing such a symptom complex in US military combat divers off Key West, FL. It is unclear what species caused the injuries, but a member of the Carybdeid genus seems most likely.

Background: Many venomous marine creatures inhabit Australian waters, causing significant morbidity and occasional fatalities. Part 1 of this article looks at jellyfish envenomations, an important overall cause of marine injuries., Objective: To discuss the features of envenomation by some of the more commonly encountered jellyfish of medical significance, and the recommended first aid and medical management of such envenomations., Discussion: It is intended that the information contained in this article will be informative to general practitioners dealing with jellyfish stings throughout Australia. Much of what we know has come from the astute observations of GPs in tropical Australia. However, there remains a lot to be learnt about jellyfish envenomation.

The pharmacological and biochemical isolation of cnidarian venoms has been hindered by difficulties with both extracting pure venom from nematocysts and venom stability. The development of a new technique to extract active, pure venom of Chironex fleckeri and Chiropsalmus sp. has enabled identify both neurotoxic and myotoxic activity in their venoms. These activities are similar, but not identical in each species. Venom (50 micro g/ml) from both species significantly inhibited indirect and direct twitches of the chick biventer nerve-muscle preparation. Pre-incubation with 1U/ml box jellyfish antivenom did not have any significant effect on venom-induced reductions of indirect twitches. However, this activity was markedly attenuated by prior addition of 5U/ml antivenom, albeit to a lesser degree for Chiropsalmus sp. In contrast, prior addition of 5U/ml box jellyfish antivenom did not neutralise the myotoxic activity of C. fleckeri venom (50 micro g/ml), although it did inhibit the myotoxicity produced by Chiropsalmus sp. venom (50 micro g/ml). Antivenom (5U/ml) added 1h after the addition of C. fleckeri venom (50 micro g/ml) had no effect on the indirect or direct twitches of the skeletal muscle preparation. However, it partially restored the reduction in indirect twitch height caused by Chiropsalmus sp. venom (50 micro g/ml). Myotoxicity was confirmed in muscle preparations stained with hematoxylin and eosin.Therefore, although antivenom was able to neutralize the neurotoxic effects of both species, and the myotoxic effects of Chiropsalmus sp., when added prior to venom, it was unable to reverse the effects after venom addition. This suggests that antivenom is unlikely to be useful in the treatment of neurotoxic or myotoxic effects in patients, although these effects are rarely seen clinically.

We conducted two studies to determine whether the minimum clinically significant difference in the visual analog scale (VAS) for nearly simultaneous and brief-interval serial assessments of pain is less than that for pain assessment at 20- to 30-minute intervals, using a 10-cm VAS. The first study was a blinded, randomized, placebo-controlled paired trial comparing the pain of intravenous cannulation in both hands (20-minute application of a eutectic mixture of local anesthetics v placebo) of study subjects. The second study was a non-blinded, randomized, paired trial of different treatments for jellyfish stings. In the first study, 37 of 40 subjects indicated that one hand experienced more pain than the other. Eleven of these 37 subjects (30%) indicated differences in VAS values of 1.0 cm or less, with a minimum value of 0.5 cm. In the second study, for all the VAS-based pain comparisons, VAS differences of

Haemodynamic effects of saline-extracted venom from nematocysts isolated from tentacles of the box-jellyfish Chiropsalmus quadrigatus (Habu-kurage) were investigated. In anaesthetized rabbits, i.v. injections of the venom produced hypotension following a transient hypertension. Mean femoral arterial blood flow markedly decreased immediately after the injection and femoral vascular resistance increased. Left ventricular dP/dt remarkably decreased after a transient and small increase, and heart rate decreased. Left ventricular end-diastolic pressure markedly elevated. All of the above changes by 0.2-5 microg/kg of the venom expressed as the amount of protein were seen dose-dependently and occurred without tachyphylaxis. In five of seven animals received an injection of the venom at 10 microg/kg, irreversible cardiac arrest occurred. Changes produced by 1 or 2 microg/kg of the venom were significantly attenuated either by heating the venom at 40 degrees C for 10min or by pretreatment with diltiazem. These results indicate that the venom from Habu-kurage has both vasoconstrictor and cardiodepressive effects, and suggest that these thermolabile actions may be due partly to activation of voltage-dependent calcium channels and probably subsequent calcium-overload.

Interest in envenoming syndromes caused by Australian jellyfish has been intense since the deaths in early 2002 of two tourists in Queensland, attributed to the Irukandji syndrome. We review current knowledge of these envenoming syndromes, mechanisms of venom action and therapy, focusing on the deadly box jellyfish, Chironex fleckeri, and the array of jellyfish thought to cause the Irukandji syndrome. Current understanding of jellyfish venom activity is very limited, and many treatments are unproven and based on anecdote.

Objectives: (1) To identify the causative jellyfish species by examining skin scrapings in patients presenting to Cairns Base Hospital with marine stings, and (2) to describe clinical outcomes of those with Irukandji syndrome and those in whom nematocysts were identified from skin scrapings., Design and Setting: (1) A retrospective case series of 128 patients, identified from Cairns Base Hospital emergency department records with discharge diagnoses of marine stings between 1 July 2001 and 30 June 2002. (2) A prospective study of skin scrapings from 50 patients presenting with marine stings from the same period., Main Outcome Measures: Number of patients with Irukandji syndrome, their opioid requirements and cardiac findings (where available); identification of causative species from nematocysts isolated from skin scrapings., Results: 116 patients retrospectively identified with marine stings had Irukandji syndrome. Of 50 patients who had skin scrapings, 39 had nematocysts consistent with Carukia barnesi. Symptoms experienced ranged from local pain alone to severe Irukandji syndrome with elevated troponin I levels, changes on electrocardiogram, cardiac dysfunction on echocardiography, and high opioid dose requirements. One patient had an unidentified cnidome on his skin scraping. He developed severe Irukandji syndrome and subsequently died from its complications., Conclusion: This is the first published report of Carukia barnesi being successfully identified from skin scrapings. Most patients with identifiable cnidomes experiencing Irukandji syndrome were stung by Carukia barnesi, which we show causes a wide range of illness, including cardiac dysfunction. Our finding of a cnidome not consistent with Carukia barnesi in the setting of Irukandji syndrome makes it possible that other species of jellyfish may also cause this syndrome.

There is an enormous diversity and complexity of venoms and poisons in marine animals. Fatalities have occurred from envenoming by sea snakes, jellyfish, venomous fish such as stonefish, cone snails, and blue-ringed octopus. Deaths have also followed ingestion of toxins in shellfish, puffer fish (Fugu), and ciguatoxin-containing fish. However antivenoms are generally only available for envenoming by certain sea snakes, the major Australian box jellyfish (Chironex fleckeri) and stonefish. There have been difficulties in characterizing the toxins of C. fleckeri venom, and there are conflicting animals studies on the efficacy of C. fleckeri antivenom. The vast majority of C. fleckeri stings are not life-threatening, with painful skin welts the major finding. However fatalities that do occur usually do so within 5 to 20 minutes of the sting. This unprecedented rapid onset of cardiotoxicity in clinical envenoming suggests that antivenom may need to be given very early (within minutes) and possibly in large doses if a life is to be saved. Forty years of anecdotal experience supports the beneficial effect of stonefish antivenom in relieving the excruciating pain after stonefish spine penetration. It remains uncertain whether stonefish antivenom is efficacious in stings from spines of other venomous fish, and the recommendation of giving the antivenom intramuscularly needs reassessment.

Objective: To determine the effect of temperature on lethality of venom from Chironex fleckeri (the potentially fatal box jellyfish)., Design: Venom extracted from nematocysts of mature Chironex fleckeri specimens was exposed to temperatures between 4 degrees C and 58 degrees C for periods of two, five or 20 minutes, and then injected into freshwater crayfish (Cherax quadricarinatus) to assess lethality., Main Outcome Measure: Venom lethality, assessed as time to cardiac standstill in crayfish after intramuscular injection., Results: Venom lethality was significantly affected by both temperature (F(7,34) = 21915; P < 0.0001) and time of exposure (F(2,34) = 9907; P < 0.0001). No significant loss of lethality was seen after exposure to temperatures or= 43 degrees C, venom lost its lethality more rapidly the longer the exposure time. Venom was non-lethal after exposure to 48 degrees C for 20 minutes, 53 degrees C for five minutes, and 58 degrees C for two minutes., Conclusion: Exposure to heat dramatically reduces the lethality of extracted C. fleckeri venom. Although heat application may be of limited use in treating C. fleckeri envenoming because of the speed of symptom onset, its use in other box-jellyfish envenomings, such as Irukandji syndrome, requires investigation.

The objective of the study was to compare cutaneous treatments (heat, papain and vinegar) for acute jellyfish (Carybdea alata) stings. Healthy adult volunteer subjects received a single-tentacle jellyfish sting on each forearm. One forearm was treated with hot-water immersion (40-41 degrees C). This was compared with the other forearm, which was randomized to a comparison treatment of papain meat tenderizer or vinegar. Pain was measured at 0, 2, 4, 6, 8, 10, 15, and 20 minutes using a 10-cm visual analog scale (VAS). For 25 subject runs, the average VAS scores at t = 0 were 3.6 cm (hot water) and 3.7 cm (comparison treatment). At t = 4 minutes (2 minutes after treatment had started), the differences between hot-water and comparison group VAS scores were 2.1 cm versus 3.2 cm, respectively. The mean difference between hot-water and comparison treatments was 1.1 cm (95% confidence interval, 0.6 to 1.6). At t = 20 minutes (the end of the study period), the differences between hot-water and comparison group VAS scores were 0.2 cm versus 1.8 cm, respectively. The mean difference between hot-water and comparison treatments was 1.6 cm (95% confidence interval, 0.9 to 2.3). This study suggests that the most efficacious initial treatment for C alata jellyfish envenomation is hot-water immersion to the afflicted site., (Copyright 2002, Elsevier Science (USA). All rights reserved.))