The staggering numbers prompted the World Health Organization to include snakebite envenoming on its list of high-priority neglected tropical diseases in 2017.
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Envenoming mice with Mipartoxin-I causes bilateral ptosis and progressive respiratory paralysis. Following a decrease in activity and respiratory paralysis, mice die a few hours after envenoming. The LD50 of mipartoxin-I is 0.06 μg/g body weight.
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In 2018, the World Health Organization listed snakebite envenoming as a neglected tropical disease. In 2019, they launched a strategy to prevent and control snakebite envenoming, which involved a program targeting affected communities and their health systems.New monoclonal antibodies, polymer gels and a small molecule inhibitor called Varespladib are in development.
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There has been no reported case of severe envenoming by female Sydney funnel-web spiders, which is consistent with the finding that the venom of female specimens is less potent than the venom of their male counterparts. In the case of severe envenomation, the time to onset of symptoms is less than one hour, with a study about Sydney funnel-web spider bites finding a median time of 28 minutes. This same study revealed that children are at particular risk of severe Sydney funnel-web spider envenoming, with 42% of all cases of severe envenoming being children. There is at least one recorded case of a small child dying within 15 minutes of a bite from a funnel-web.
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Death may occur as a result of bites or stings. The rate of envenoming is described as the likelihood of venom successfully entering a system upon bite or sting.
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Both cardiotoxicity and reliable nonspecific signs of envenoming were absent. Bites by the Philippine cobra produce a distinctive clinical picture characterized by severe neurotoxicity of rapid onset and minimal local tissue damage.
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Victims are likely to feel progressively weaker after envenoming. Envenoming can result in death, which can occur between 5 and 15 hours, but it is also possible for death to occur within one hour. Examples of common symptoms that occur after a sting are: drowsiness, drooping eyelids, paralysis of neck muscles, loss of muscle coordination, and abdominal pain. A monovalent antivenom (an antivenom that heals stings of specific species ) called Anti-scorpionique is available to treat stings from a black fat-tailed scorpion.
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However, one scientific animal study found no benefit in preventing necrosis, with the study's results showing it increased inflammation and caused symptoms of systemic envenoming. The authors concluded the results of the study did not support the use of topical nitroglycerin in brown recluse envenoming. Antivenom is available in South America for the venom of related species of recluse spiders. However, the bites, often being painless, usually do not present symptoms until 24 or more hours after the event, possibly limiting the effect of this intervention.
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Snake species in the genus Philodryas are not considered venomous.Araújo ME, Santos AC (1997). "Cases of human envenoming caused by Philodryas olfersii and Philodryas patagoniensis (Serpentes: Colubridae)". Rev. Soc. Bras. Med. Trop. 30 (6): 517-519.
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Anti-scorpion venom serum (AScVS) is an effective and safe method of therapy in severe scorpion envenoming syndrome. Compared with other therapies like alpha blockers it has a relatively short recovery period (10 vs 16–42 hours).
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The exact mechanism of action of the venom is unknown, but catecholamine excess may be an underlying mechanism in severe cases. Animal studies appear to confirm a relationship between envenoming and an increase in circulating noradrenaline and adrenaline.
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Atractaspidinae are a family of small, inoffensive snakes with low chances of envenoming. Native examples include mole vipers, stiletto snakes, and burrowing asps. Most cases of evenomation are caused by the carpet viper, the black-necked spitting cobra, and the puff adder.
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The efforts of Schistosomiasis Control Initiative to combat neglected diseases include the use of rapid-impact packages: supplying schools with packages including four or five drugs, and training teachers in how to administer them. Health Action International based in Amsterdam worked with the WHO to get snakebite envenoming on the list of neglected tropical diseases.
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The venom of the northern death adder is highly potent against the human organism. It contains pre- and postsynaptic neurotoxins, possibly myotoxins and anticoagulants as well. An envenoming by this snake is very dangerous, and all bites should be treated as medical emergencies. Main effects include local pain and flaccid paralysis, death can be caused by respiratory failure.
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There were two deaths, both in patients who were moribund upon arrival at the hospital. Three patients developed necrosis, and 14 individuals with systemic symptoms had no local swelling at all. Both cardiotoxicity and reliable nonspecific signs of envenoming were absent. Bites by the Philippine cobra produce a distinctive clinical picture characterized by severe neurotoxicity of rapid onset and minimal local tissue damage.
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It's responsible by more fatalities than all other african snakes combined, its venom is compound of Procoagulants, anticoagulants, hemorraghins, neprhotoxins and necrotoxins, symptoms of their bites include local pain, swelling, bleeding necrosis and disfigurement which may result in amputation. Systemic symptoms include coagulopathy, hemorraghes, shock, renal failure and blindness. The envenoming rate is 80% and the lethality rate is 10-20%.
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People most commonly feel a sharp pain after these stings, similar to that from an electric shock. Some patients develop a systemic skin reaction after being stung. Localised envenomation occurs with every sting, but severe envenoming only occurs if someone has been stung many times (as many as 50 to 300 stings in adults). The heart rate increases, and blood pressure falls rapidly.
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Malayan pit viper (Calloselasma rhodostoma) The Malayan pit viper (Calloselasma rhodostoma) is an Asian species of pitviper that is reputed to be an ill-tempered snake that is quick to strike in defense. This species is one of the main causes of snakebite envenoming in Southeast Asia. However, mortality rate among untreated bite victims is very low (1-10%). Although bites are common, death is very rare.
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There is an overall shortage of antivenom to treat snakebites. Because of this shortage, clinical researchers are considering whether lower doses may be as effective as higher doses in severe neurotoxic snake envenoming. Snake antivenom is complicated and expensive for manufacturers to produce. When weighed against profitability (especially for sale in poorer regions), the result is that many snake antivenoms, world-wide, are very expensive.
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A dry bite is a bite by a venomous creature in which no venom is released. Dry snake bites are called "venomous snake bite without envenoming". Dry bites can occur from all snakes, but their frequency varies from species to species. For example, Australian eastern brown snakes (Pseudonaja textilis) can inflict dry bites 80% of the time while taipans inflict dry bites only 5% of the time.
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In Brazil, each year almost 2,000 snakebites are due to Crotalus durissus. The only treatment for people who are envenomed by C. durissus is a specifically developed antivenom that has to be injected intravenously. With the arrival of this antivenom, the fatality rate declined from 73% to 1.5%. The dosage of the antivenom varies between 10 and 20 ampules depending on the severity of the envenoming.
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The treatment of choice is an antivenom produced by CSL Ltd in 1956 in Australia on the basis of immunised horse plasma. After being bitten the majority of patients will develop systemic envenoming of which clinical evidence is usually present within two hours. This effect can be delayed by applying first aid measures, like immobilization. Additional to neurotoxins taipan venom contains anticoagulants whose effect is also inhibited by the antivenom.
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Before this, tiger snake antivenom was used, though it was of negligible benefit in brown snake envenoming. The antivenom had been difficult to research and manufacture as the species was hard to catch, and the amount of venom it produced was generally insufficient for horse immunization, though these challenges were eventually overcome. Dogs and cats can be treated with a caprylic acid-fractionated, bivalent, whole IgG, equine antivenom.
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The comparatively low venom yield (6.4–11 mg dried venom) and short to fangs of the tiger rattlesnake possibly prevent severe envenoming in adult humans. However, the clinical picture could be much more serious if the person bitten was a child or an individual with a slight build. The early therapeutic use of antivenom is important if significant envenomation is suspected. Despite the low venom yield, a bite by this rattlesnake should be considered a life-threatening medical emergency.
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Common death adder (Acanthophis antarcticus) The Common death adder (Acanthophis antarcticus) is a highly venomous snake species with a 50-60% untreated mortality rate. It is also the fastest striking venomous snake in the world.Fastest striking snake A death adder can go from a strike position, to strike and envenoming their prey, and back to strike position again, in less than 0.15 seconds. The SC value is 0.4 mg/kg and the venom yield per bite can range anywhere from 70–236 mg.
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According to (Sanchez et al., 1992), who used wild specimens from Pará, Brazil, the average venom yield per bite was 324 mg, with a range of 168–552 mg (dry weight). Brown (1973) gives the following values for mice: 1.5 mg/kg IV, 1.6–6.2 mg/kg IP, 6.0 mg/kg SC. He also notes a venom yield of 200–411 mg. Human envenoming by this species, although infrequent, can be rather severe due to the large volumes of venom injected.
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The neotropical rattlesnake in Brazil is of special importance because of the high incidence of envenoming and mortality rates. Clinically, venom of this snake does not usually cause local effects at the bite site and is usually painless. However, the etiology progresses to systemic neurotoxic and myalgic symptoms, with frequent kidney failure accompanied by acute tubular necrosis. The huge area of distribution, potent venom in fairly large quantities and a definite willingness to defend themselves are important factors in their dangerousness.
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In 1896, Chamberlain wrote to his aunt: > The English press is the most insufferably arrogant, generally ignorant, the > most passionately one-sided and narrow-minded in its judgments that I know; > it is the universal bully, always laying down the law for everybody, always > speaking as if it were umpire of the universe, always abusing everybody all > round and putting party spirit in all its judgments, envenoming thus the > most peaceful discussions. It is this and this only which has made England > hated all the world over.
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Patients may suffer a loss of sense of smell (anosmia); this is unrelated to the severity of the envenoming and can be temporary or permanent. Although the venom contains the three-finger toxin α-elapitoxin-Ppr1, which acts as a neurotoxin in laboratory experiments, neurotoxic symptoms are generally absent in clinical cases. A biologically active agent—pseudexin—was isolated from red-bellied black snake venom in 1981. Making up 25% of the venom, it is a single polypeptide chain with a molecular weight around 16.5 kilodaltons.
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Many-banded krait (Bungarus multicinctus) The Many-banded krait (Bungarus multicinctus) is the most venomous krait species known based on toxinological studies conducted on mice. The venom of the many-banded krait consists of both pre- and postsynaptic neurotoxins (known as α-bungarotoxins and β-bungarotoxins, among others). Due to poor response to antivenom therapy, mortality rates are very high in cases of envenomation - up to 50% of cases that receive antivenom are fatal. Case fatality rates of the many-banded krait envenoming reach up to 77%–100% without treatment.
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In Brazil and probably also in other countries in their area of distribution, this species is probably the most dangerous rattlesnake. After the fer-de- lance (Bothrops asper), it is the most common cause of snake envenoming. In the first half of the 20th century as well as in the 1950s and 1960s, 12% of treated cases ended fatally. Untreated cases apparently had a mortality rate of 72% in the same period, but this was due to the fact that there was no antivenom, poor medical care and neglect (Rosenfeld, 1971).
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Most of the Pacific Islands are free of terrestrial snakes, although sea snakes are common in coral reefs. In the Oceanian realm, only Micronesia and Tonga, where at least 10 envenomations occur annually, face an appreciable burden of snakebite. In Australia, there are many more annual cases of spiderbite and jellyfish envenomation than snakebite; however, when considering the number of fatal cases, snakebite is the most serious type of envenoming. Australia is unique in that it is the only continent where venomous snakes constitute the majority of species.
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Black fat–tailed scorpions use neurotoxic venom, which is fast acting and can be absorbed very quickly, because of the small molecular weight of the proteins that make up the venom. These neurotoxins act on the central nervous system, causing paralysis in the nerves that are responsible for respiration, which ultimately causes death by respiratory failure. The neurotoxins may also cause widespread neuronal excitation, symptoms of which can include pain, sweating, salivation, and tearing. Severe envenomation is likely, as the rate of envenoming is 10-20%, making it potentially lethal.
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Within this genus, there are a few species in which dry bites are very rare. Envenoming occurs in at least 75-80% of bite cases involving these species. The species which typically cause envenomation in the majority of their bites include some of the more dangerous and venomous species of this genus: Naja oxiana, Naja philippinensis, Naja nivea, and Naja samarensis. There are many more species within the genus which have not yet been subject to much research and studies, and as a result, very little is known about their behaviour, venom, diet, habitat and general temperaments.
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These are cobra, krait, Russell's viper, sawscaled viper, green snakes, and sea snakes. However, most of the bites are reported by nonvenomous snakes and even as many as 40% bites inflicted by venomous snakes do not produce signs of envenoming. On the Indian subcontinent, almost all snakebite deaths have traditionally been attributed to the Big Four, consisting of the Russell's viper, Indian cobra, saw-scaled viper, and the common krait. However, studies have shown that the hump-nosed viper, previously considered essentially harmless and misidentified as the saw-scaled viper, is capable of delivering a fatal bite.
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This is thought to be due to the low concentration of the toxin in the venom, which is injected in only small amounts compared with other snake species. Analysis of venom in 2016 found—unlike most other snake species—that the venom of juvenile eastern brown snakes differed from that of adults; prothrombinases (found in adults) were absent and the venom did not affect clotting times. Snakes found with a similar profile generally preyed upon dormant animals such as skinks. The eastern brown snake is the second-most commonly reported species responsible for envenoming of dogs in New South Wales.
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The venom affects the nervous system and the blood's ability to clot, and bite victims may experience headache, nausea and vomiting, collapse, convulsions (especially in children), paralysis, internal bleeding, myolysis (destruction of muscle tissue) and kidney damage. In a single study done in Papua New Guinea, 166 patients with enzyme immunoassay-proven bites by Papuan taipans (Oxyuranus scutellatus canni) were studied in Port Moresby, Papua New Guinea. Of the 166 bite victims, 139 (84%) showed clinical evidence of envenoming: local signs were trivial, but the majority developed hemostatic disorders and neurotoxicity. The blood of 77% of the patients was incoagulable and 35% bled spontaneously, usually from the gums.
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It is classified as a snake of medical importance by the World Health Organization. Dangerous snake poster published by Museum Victoria in 1877 Clinically, the venom of the eastern brown snake causes venom-induced consumption coagulopathy; a third of cases develop serious systemic envenoming including hypotension and collapse, thrombotic microangiopathy, severe haemorrhage, and cardiac arrest. Other common systemic symptoms include nausea and vomiting, diaphoresis (sweating), and abdominal pain. Acute kidney injury and seizures can also occur. Onset of symptoms can be rapid, with a headache developing in 15 minutes and clotting abnormalities within 30 minutes; collapse has been recorded as occurring as little as two minutes after being bitten.
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Box jellyfish warning signpost at a Cape Tribulation beach in Queensland, Australia Jellyfish/stinger net exclosure at Ellis Beach, Queensland, Australia Although the box jellyfish has been called "the world's most venomous creature", only a few species in the class have been confirmed to be involved in human deaths, and some species pose no serious threat at all. In Australia, fatalities are most often caused by the largest species of this class of jellyfish, Chironex fleckeri. Researchers at the University of Hawaii's Department of Tropical Medicine found the venom causes cells to become porous enough to allow potassium leakage, causing hyperkalemia, which can lead to cardiovascular collapse and death as quickly as within 2 to 5 minutes. It was postulated that a zinc compound may be developed as an antidote. In Australia, C. fleckeri has caused at least 64 deaths since the first report in 1883, but even in this species most encounters appear to result only in mild envenoming.
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Human fatalities as a result of bites from this species are rare due to the fact that this species does not often cross paths with humans, but bites have occurred and the majority of the recorded bites have been fatal. The three species of green mambas, including the western green mamba, have venom toxicities that are similar to and comparable to many species of cobras, but green mamba bites often present with more severe and life-threatening symptoms in a shorter period of time. Mortality rates are also higher among green mamba bite victims than with cobra bite victims. Although bites by Dendroaspis viridis are not well documented and the rate of bites, envenoming and fatality is not well known, it appears that bites attributed to this species produce more severe envenomation than bites caused by Dendroaspis angusticeps (eastern green mamba), but far less severe than bites caused by Dendroaspis polylepis (black mamba).
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