Vinegar as a disarming agent to prevent further discharge of the nematocysts of the stinging hydromedusa Olindias sambaquiensis.

Olindias sambaquiensis, known as agua viva, is an endemic hydromedusa that is distributed from latitude 23 degrees to 42 degrees south in the southwestern Atlantic Ocean and is known to cause severe stings. This is the first report of the use of vinegar in disarming O sambaquiensis nematocysts and includes preliminary observations on its use in managing the stings of hydromedusae.

Optimization and preliminary characterization of venom isolated from 3 medically important jellyfish: the box (Chironex fleckeri), Irukandji (Carukia barnesi), and blubber (Catostylus mosaicus) jellyfish.

OBJECTIVE: To optimize venom extraction and to undertake preliminary biochemical studies of venom from the box jellyfish (Chironex fleckeri), the Irukandji jellyfish (Carukia barnesi), and the blubber jellyfish (Catostylus mosaicus). METHODS: Lyophilized crude venoms from box jellyfish tentacles and whole Irukandji jellyfish were prepared in water by homogenization, sonication, and rapid freeze thawing. A second technique, consisting of grinding samples with a glass mortar and pestle and using phosphate-buffered saline, was used to prepare crude venom from isolated nematocysts of the box jellyfish, the bells of Irukandji jellyfish, and the oral lobes of blubber jellyfish. Venoms were compared by use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot test. Toxicity of some venoms was determined by intravenous median lethal dose assay in mice. RESULTS: Different venom extraction techniques produced significantly different crude venoms for both box and Irukandji jellyfish. Irukandji and blubber venom SDS-PAGE protein profiles were established for the first time. Analysis of Western blot tests revealed that box jellyfish antivenin reacted specifically with the venom of each jellyfish. Toxicity was found in Irukandji jellyfish venom derived by use of the mortar-and-pestle method, but not in the lyophilized venom. CONCLUSIONS: Glass mortar-and-pestle grinding and use of an appropriate buffer was found to be a simple and suitable method for the preparation of venom from each jellyfish species studied. This study contributes to biochemical investigations of jellyfish venoms, particularly the venom of the Irukandji jellyfish, for which there are, to our knowledge, no published studies. It also highlights the importance of optimizing venom extraction as the first step toward understanding the complex biological effects of jellyfish venoms.

Irukandji and Chironex fleckeri jellyfish envenomation in tropical Australia.

OBJECTIVE: To compare the temporal distribution of Irukandji and Chironex fleckeri stings, the demographics of victims, the prevailing physical conditions at the time of a sting, and the prevalence of unsuitable first aid strategies. METHODS: Retrospective assessment of 478 Chironex and 544 Irukandji stings in Queensland and the Northern Territory of Australia. RESULTS: Adolescent and young adult males were the most common victims of Irukandji (median age 21 years) and Chironex stings (median age 16 years). Most Chironex stings occurred on the legs, while Irukandji stings were more common on the arms. Vinegar was correctly used to remove tentacles in 90.5% of Chironex stings, whereas inappropriate treatments were used in the remaining cases. Chironex stings were reported in every month in the Northern Territory, and in all months but June and July in Queensland. The peak prevalence for Chironex stings occurred in January in both areas, while the number of Irukandji stings peaked in December in Queensland and in May in the Northern Territory. Chironex stings were more common on still, cloudy days, whereas Irukandji stings were more common on still, clear days. Irukandji stings were more frequent than Chironex stings on rough days (P = .0005). Chironex and Irukandji stings were similar with respect to tides, moon phases, and rainfall. CONCLUSIONS: This study failed to predict exact weather patterns or other contributing factors to reduce the risk of stings to an acceptable level, but did identify several factors that increase the incidence of stings. The "stinger-free" season reported on Chironex warning signs is inaccurate and should be changed to warn bathers that Chironex may be present year round, particularly in the Northern Territory.

Dangers in the ocean: the traveler and marine envenomation. I. jellyfish.

Envenomation by marine creatures is more common than is often realized, and regularly accounts for both death and severe morbidity in humans. Worldwide marine envenomation morbidity and mortality result from two main animal groups: (1) jellyfish, and (2) "other" marine animals. Venomous jellyfish are discussed in part I of this article, with relevant information on their distribution and appearance, and on symptoms of envenomation; first aid and medical treatment are also suggested.

Autonomic neurotoxicity of jellyfish and marine animal venoms.

Venoms and poisons of jellyfish and other marine animals can induce damage to the human nervous and circulatory systems. Clues to the pathogenesis and clinical manifestations of these lesions can be obtained from data of human envenomations and animal experimentation. Because many investigators are unaware that marine animal venoms have autonomic actions, this paper aims to elucidate the broad antagonistic or toxic effects these compounds have on the autonomic nervous system. Marine venoms can affect ion transport of particularly sodium and calcium, induce channels or pores in neural and muscular cellular membranes, alter intracellular membranes of organelles and release mediators of inflammation. The box jellyfish, particularly Chironex fleckeri, in the Indo-Pacific region, is the world's most venomous marine animal and is responsible for autonomic disorders in patients. The symptoms induced by these venoms are vasospasm, cardiac irregularities, peripheral neuropathy, aphonia, ophthalmic abnormalities and parasympathetic dysautonomia. Cases of Irukandji syndrome, caused by the jellyfish Carukia barnesi, have symptoms that mimic excessive catecholamine release. Coelenterate venoms can also target the myocardium, Purkinje fiber, A-V node or aortic ring. Actions on nerves, as well as skeletal, smooth or cardiac muscle occur. Recent studies indicate that the hepatic P-450 enzyme family may be injured by these compounds. The multiplicity of these venom activities means that a thorough understanding of the sting pathogenesis will be essential in devising effective therapies.

Dangers in the ocean: the traveler and marine envenomation. II. Marine vertebrates.

Envenomation both from jellyfish and other marine animals causes human deaths and severe morbidity in many countries in the world having tropical, or subtropical waters. In part II the world distribution of venomous marine vertebrates is discussed, together with simple first aid and effective medical treatment. Suggestions are made for the awareness and prevention of marine envenomation. With travel becoming more popular than ever, general practitioners and travel medicine consultants must routinely advise their patients on the worldwide hazards of marine envenomation.

A Queensland family with ciguatera after eating coral trout.

Ciguatera (poisoning caused by eating fish contaminated with algal toxins) is usually diagnosed clinically. We describe a Queensland family of four (including a pregnant woman) with ciguatera, confirmed by bioassay of the implicated fish for ciguatoxin. All four recovered, illustrating the effectiveness of treatment with intravenous mannitol. At birth, the infant appeared to suffer no adverse effects attributable to ciguatera; to our knowledge, this is the first report of the effect of severe ciguatera in the first trimester of pregnancy.

Success of surf lifesaving resuscitations in Queensland, 1973-1992.

OBJECTIVE: To determine the success of resuscitations performed by Queensland surf lifesavers and the factors associated with successful resuscitation. DESIGN: Retrospective case survey, using data from Surf Life Saving Association of Australia resuscitation report forms. SETTING: 54 Queensland beaches patrolled by surf lifesavers, and nearby areas, between 1973 and 1992. OUTCOME MEASURES: Reasons and success rates for resuscitation, distance from surf clubhouse, whether inside patrolled area, victim's age, sex, facial colour on presentation, occurrence of vomiting, airway difficulties and involvement of alcohol. RESULTS: 171 resuscitations were reported (80% involving males and 20% females), with a success rate of 67%. Seventy-two per cent were performed during patrol hours, 17% within patrolled areas (95% successful) and 55% outside patrolled areas (only 62% successful) (P = 0.004 for difference in success rates); resuscitation success rates fell with increasing distance from the surf clubhouse (P = 0.009). Reasons for resuscitation were: immersion, 70% (success rate, 68%); collapse, 22% (success rate, 47%); and surf or beach injury, 7% and 1%, respectively (success rate, 100% for each). Resuscitation was more likely to be successful if the victim's facial colour on presentation was normal, pale or blue, but not if grey, and if the victim did not vomit or regurgitate. CONCLUSIONS: Resuscitation by surf lifesavers was highly successful when the victim was close to the surf patrol, indicating a need for funding to expand patrol areas. Public awareness of the greater safety of "bathing between the flags" (in the delineated patrol area) should be increased.

Venomous bites and stings.

Travellers to tropical countries are often extremely concerned about the risk of bites and stings by venomous animals. This fear prompts many enquiries, usually at the last moment before departure, about the possibility of carrying first aid kits and antivenoms. In fact, these accidents are extremely rare because most travellers wear shoes and are far less exposed to venomous animals than indigenous peoples for whom bites and stings may be important causes of death or morbidity.

First aid treatment of jellyfish stings in Australia. Response to a newly differentiated species.

Vinegar has been shown to inhibit neomatocyst discharge in Chironex fleckeri, the deadly north Australian box-jellyfish, and application of vinegar has become accepted first aid, not only for box-jellyfish stings, but also for stings by other Australian jellyfish. However, in a newly differentiated species of Physalia in Australian waters, which causes severe envenomation, vinegar was found to cause discharge in up to 30% of neomatocysts. In treating these stings, the use of vinegar is not recommended as it may increase envenomation. Stings from the single-tentacled Physalia utriculus (the "bluebottle") are not severe, tentacles with unfired nematocysts rarely adhere to the victim's skin and vinegar dousing is not required. Vinegar treatment is therefore an unnecessary step in the first aid management of any Physalia sting but remains an essential first aid treatment for all cubozoan (box) jellyfish tested to date.