Venom Legal Definition
Table 22.1 — Local, systemic, hematological and neurological signs and symptoms of snakebite poisoning. Venom is found in other reptiles such as the Mexican pearl lizard,[35] the Gila monster,[36] and some monitor lizards, including the Komodo dragon. [37] Mass spectrometry has shown that the mixture of proteins present in their venom is as complex as the mixture of proteins found in snake venom. [37] [38] Some lizards have a venom gland; They form a hypothetical clade, Toxicofera, which contains the suborders Serpentes and Iguania as well as the families Varanidae, Anguidae and Helodermatidae. [39] Laboratory tests should be performed as soon as the patient is stabilized upon entering the health care facility. If the patient`s initial tests are normal, they should be repeated 2 and 3 hours later (5 hours after the initial evaluation) to ensure that there have been no delayed effects of poisoning. With a little snake poisoning (for example, a malaise viper bite), the effects may be delayed or recurring after a few days. Poisoning led to 57,000 deaths in 2013, up from 76,000 in 1990. [45] The toxins, present in more than 173,000 species, have the potential to treat a variety of diseases that have been studied in more than 5,000 scientific papers.
[36] The poison can be delivered by biting or stinging. Both mechanisms can leave recognizable traces, but do not always do so. Even for snakes, traces may not be visible despite serious or even fatal poisoning. Therefore, the determination of the existence of poisoning is based not only on the location of bite/puncture marks, but also on the detection of local or systemic effects of poisoning or on the detection of poison. The latter is just a routine diagnostic option in Australia and New Guinea for region-specific snakes. In all other areas, it remains essentially a limited research tool. Clownfish still live among the tentacles of venomous sea anemones (an obligate symbiosis for fish),[66] and resist their venom. [67] [68] Only 10 known species of anemones are hosts of clownfish and only certain pairs of anemones and clownfish are compatible. [69] [70] All sea anemones produce toxins that are released by the excretion of nematocysts and mucus secretions. Toxins consist of peptides and proteins. They are used to acquire prey and deter predators by causing pain, loss of muscle coordination and tissue damage.
Clownfish have a protective mucus that acts as chemical camouflage or macromolecular mimicry, preventing the «non-self-recognition» of the sea anemone and the discharge of nematocysts. [71] [72] [73] Clownfish may acclimatize their mucus to resemble that of a particular species of sea anemone. [73] The phylum Mollusca includes octopus and cone snails (Conus sp.). Theoctopus of toxicological importance is Hapalochlaena maculosa (blue-ringed octopus), which is found mainly in Australian waters. The blue-leaved octopus secretes tetrodotoxin (the same toxin found in pufferfish) into its salivary gland. The beak of the octopus pierces the skin and provides tetrodotoxin. Tetrodotoxin blocks sodium channels in neurons, causing paralysis. The poison also contains other toxins, including vasoactive agents and enzymes that cause local tissue damage. Cone snails have a hollow proboscis with a tooth that can be elongated to inject poison to the victim. The venom of the Conus species contains conotoxins that target several receptors, including tension, ligand and G-mediated receptors.
Conotoxins cause a variety of symptoms such as severe pain, weakness, tissue ischemia, cyanosis and numbness. Systemic symptoms are usually neurological and include aphonia, aphasia, weakness, paralysis, respiratory failure, cardiovascular collapse and possibly death. Venom is found in about 200 cartilaginous fish, including rays, sharks and chimaeras; Catfish (approx. 1000 poisonous species); and 11 clades of stingrayfish (Acanthomorpha), including scorpionfish (over 300 species), stonefish (over 80 species), gurnard, blennies, rabbitfish, surgeonfish, some velvetfish, some toadfish, coral duikfish, velvet goldfish, cats, redfish, deep-sea scorpionfish, wasps, weasels and astronomers. [27] Venom immunotherapy (VIT) is indicated in children and adults with a history of severe RS (grade III/IV) if venom sensitization has been demonstrated by skin and/or blood tests. LLRs or unusual reactions do not require VIT. TIV is also recommended for patients who have repeated, non-life-threatening mild reactions and are at high risk of re-exposure, such as beekeepers or family members. Concomitant cardiovascular disease, mastocytosis, and severe impairment of quality of life due to venom allergy are relative indications for TIV in patients with non-life-threatening puncture reactions.19,24 Since early signs of poisoning may be rapid progressive neurotoxicity and paralysis is difficult to reverse, Some authorities have suggested administering antivenom in cases where poisoning precedes the onset of clinical symptoms is possible. Others highlighted the incidence of paralysis of the respiratory muscles leading to the need for intubation and respiratory support, and possible geographical differences in snake toxicity, and recommended observation and antivenom treatment only after confirmation of progressive symptoms. Recent analyses of the national database have shown no significant difference in clinical severity between coral snake poisoning in Florida and Texas, which promotes early treatment in cases of suspected poisoning. In February 2020, Pfizer listed the current new coral snake antivenom as in-stock and ready to ship (order number: 844-646-4398).
Poison control centres will also have information on the availability of antidotes in their areas. If paralysis has progressed to significant airway impairment, complete or partial reversal with the antidote may not be possible, and aggressive and careful respiratory support, including intubation and ventilation, may be required for days or weeks. When FDA-approved coral snake antivenom is not readily available, there have been reports of coral snake antivenoms from Mexico, Costa Rica and Brazil, as well as Australian tiger snake antivenom reversing the neurotoxicity of M. tener. The use of non-FDA foreign antidotes should be reserved for cases where an FDA-approved product is not available in a timely manner and, if possible, with prior approval from the FDA`s Bureau of Biologics (240-402-8010; 800-835-4709; Emergency after hours: 866-300-4374; 301-796-8240; [ email protected]). Because these drugs are imported into the U.S. as investigational new drugs, institutional investigation review committees also have reporting requirements. American king snakes are constrictors that hunt many venomous snakes. [61] They have developed resistance that does not vary with age or exposure. [55] They are immune to the venom of snakes in their immediate vicinity, such as copper heads, cottonmouths, and North American rattlesnakes, but not to venom, for example, from the king cobra or black mambas. [62] Treatment of snake poisoning begins at the time of field poisoning, but nothing will significantly change the course of poisoning unless the wrong thing is done. Without delaying transport, the wound should be cleaned (soap and water) and straightened.
Procedures such as oral aspiration, mechanical aspiration, bleeding from the bite site, electrotherapy, cryotherapy, and tourniquet or compression bandage placement are not recommended, as all of these can lead to increased damage to the patient.[15] .
