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Invasive plants are a threat to natural ecosystems worldwide, with urban wetlands being some of the most susceptible and highly modified environments of all. The tiger snake (Notechis scutatus) is a top predator that persists in urban wetlands of south-western Australia, many of which have been degraded by introduced kikuyu grass (Cenchrus clandestinus). To evaluate the potential impact of kikuyu grass on habitat quality for tiger snakes we quantified the structural features of habitats within wetlands degraded by kikuyu grass and compared them to wetlands with native vegetation. We also examined tiger snake prey availability, assessed predation risk for juvenile snakes using clay models, and measured the thermal quality of the vegetation. Proliferation of kikuyu grass has reduced habitat structural heterogeneity by reducing available bare ground and increasing vegetation density. This homogenisation of habitat structure had little effect on the predation risk for juveniles or the thermal properties of tiger snake shelter sites; however, one key prey species, the motorbike frog, had significantly lower abundance in the most impacted habitat. Habitat types with more structural complexity also offered tiger snakes more stable thermal regimes and lower predation risk. These findings indicate that the current extent of kikuyu grass invasion offers overall similar habitat quality for tiger snakes to native vegetation and may contribute to their persistence in urban wetlands; however, both tiger snakes and their anuran prey may benefit from increased habitat structural complexity. [ABSTRACT FROM AUTHOR]

The red-bellied black snake (Pseudechis porphyriacus) is a member of the Elapidae family and is distributed on the east coast of Australia. The species is known to feed on a variety of ectothermic prey, including frogs and lizards. It is also known to be ophiophagous (snake-feeding), and stomach-content analyses suggest that P. porphyriacus also exhibits cannibalistic behavior, yet this extreme case of ophiophagy has rarely been documented. Here, a case of cannibalism in P. porphyriacus, which was observed in Lamington (Queensland, Australia), has been photographically documented and is described. [ABSTRACT FROM AUTHOR]

The eastern small eyed snake (Cryptophis nigrescens; CN) is an uncommon cause of snakebite in Australia despite the widespread distribution of the snake along the east coast of Australia. Diagnosis of envenomation relies on identification of the snake which is often not possible with animal snakebite cases. This study examined the immunoreactivity profile of CN venom towards specific rabbit IgG made against the medically relevant snake venom immunotypes found in Australia (tiger, brown, black, death adder and taipan). A simultaneous sandwich ELISA format was used to quantify CN venom binding to venom specific Protein A purified rabbit IgG. The binding profiles demonstrated weak binding of CN venom to rabbit IgG made against both tiger (N. scutatus) and black snake (P. australis) venoms with approximately 0.19% and 0.069% cross reactivity, respectively. However, the concentration of venom likely to be present in the urine of CN envenomed patients and the low cross reactivity suggest that envenomed veterinary patients are unlikely to be detected in the commercial snake venom detection kit. It is possible that CN envenomation is more common but may be underdiagnosed where snake venom antigen detection is relied upon solely. Serum biochemical abnormalities also overlap with other snake species found in the same geographical area. In respect of antivenom therapy, administration of tiger snake antivenom is supported by the binding data, but due to the low cross reactivity multiple vials may be required. Limited clinical evidence also supports the efficacy of tiger snake antivenom for envenomation by CN., (© 2024 The Author(s). Australian Veterinary Journal published by John Wiley & Sons Australia, Ltd on behalf of Australian Veterinary Association.)

The venoms of Australasian elapid snakes are known to possess coagulant activity, including some with strong procoagulant activity and others with anticoagulant activity, although the latter are less well known. This study investigates the anticoagulant activity of Australasian elapid snake venoms, and whether this activity is neutralised by commercial snake antivenom and varespladib (PLA 2 inhibiting agent). Clotting assays were completed for 34 species of Australasian elapids. Antivenom neutralisation assays with tiger snake antivenom (TSAV) were performed on five species to determine if there was cross-neutralisation. Varespladib neutralisation assays were also completed for the same five species. All Pseudechis species venoms had anticoagulant activity, except P. porphyriacus, which was procoagulant. Pseudechis species venoms had similar anticoagulant potency ranging from the most potent P. colletti venom to the least potent P. butleri venom. The three Austrelaps (copperhead) species venoms were the next most potent anticoagulants. Six further snakes, Elapognathus coronatus, Acanthophis pyrrhus, A. antarcticus, Suta suta, Denisonia devisi and D. maculata, had weaker anticoagulant activity, except for D. maculata which had similar anticoagulant activity to Pseudechis species. Tiger Snake Antivenom (1200mU/mL) neutralised the anticoagulant effect of P. australis for concentrations up to 1 mg/mL. TSAV (1200mU/mL) also neutralised P. colletti, D. maculata, A. superbus and A. pyrrhus venoms at their EC 50 , demonstrating cross neutralisation. Varespladib neutralised the anticoagulant effect of P. australis venom at 5 μM and for venoms of P. colletti, D. maculata, A. superbus and A. pyrrhus. We found anticoagulant activity to be present in six genera of Australasian snakes at low concentrations, which can be completely neutralised by both antivenom and varespladib. Anticoagulant activity in Australian elapid venoms was associated with species possessing high PLA 2 activity without procoagulant snake venom serine proteases., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Geoffrey Isbister reports administrative support was provided by National Health and Medical Research Council. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

This report details the case of a 51-year-old man with a Tiger snake bite who developed systemic envenomation, coagulopathy and thrombotic microangiopathy (TMA) requiring renal replacement therapy. He received plasma exchange as additional therapy while awaiting confirmation of the cause of the TMA. We discuss clinical decision making in detection of systemic envenomation and management of the rare complication of TMA, as well as current Australian guidelines around antivenom administration. This is the fourth known documented case of TMA from a Tiger snake bite in Australia., (© 2024 Asian Pacific Society of Nephrology.)

Introduction: Antivenom is first line treatment for snake envenomation worldwide, despite few placebo controlled clinical trials demonstrating effectiveness. We aimed to investigate whether early antivenom in red-bellied black snake ( Pseudechis porphyriacus ) bites would prevent systemic myotoxicity., Methods: We undertook a multicentre randomized placebo-controlled trial of antivenom for red-bellied black snake bites with patients recruited from the Australian Snakebite Project (July 2014 to June 2020). In addition, we report all patients with red-bellied black snake bites during the same period, comparing the same outcomes. Patients over 2 years of age with definite red-bellied black snake bites and early systemic effects were randomized to receive 50 per cent glucose (placebo) or tiger snake antivenom within 6 hours post-bite, or in the cohort group received antivenom determined by the treating clinician. The primary outcome was the proportion of patients with myotoxicity (peak creatine kinase activity >1,000 U/L). Secondary outcomes were: area under the curve of total creatine kinase elevation over 48 hours, presence of venom post-antivenom, and adverse reactions. We analyzed both the randomized control trial patients and the combination of randomized control trial and cohort patients., Results: Fifteen patients were recruited to the randomized controlled trial, and a cohort of 68 patients who were not randomized were included in the analysis. After treatment, two of seven patients given placebo had a peak creatine kinase activity >1,000 U/L versus none of the eight given antivenom (difference in favour of antivenom; 29 per cent; 95 per cent confidence interval:-18 per cent to +70 per cent; P  = 0.2). The median area under the curve of total creatine kinase elevation over 48 hours in patients given placebo was 0 U/L*h (interquartile range: 0-124 U/L*h), which was not significantly different to those given antivenom: 197 U/L*h (interquartile range: 0-66,353 U/L*h; P  = 0.26). Venom was not detected post-antivenom in six patients with measured venom concentrations given antivenom. Two patients given antivenom had immediate hypersensitivity reactions, one severe anaphylaxis, and another had serum sickness. Combining randomized and not randomized patients, three of 36 (8 per cent) administered antivenom less than 6 hours post-bite had a peak creatine kinase activity >1,000 U/L versus 17/47 (36 per cent) patients not receiving antivenom less than 6 hours post-bite (difference in favour of antivenom 29 per cent; 95 per cent confidence interval: 8 per cent to 44 per cent; P  < 0.004). Overall, 13/36 (36 per cent) patients administered antivenom within 6 hours had hypersensitivity reactions, six severe anaphylaxis (17 per cent)., Discussion: We found that early antivenom was effective in red-bellied black snake bites, and only three patients need to be given antivenom within 6 hours to prevent myotoxicity in one (number needed to treat = 3). However, one in three patients administered antivenom developed a hypersensitivity reaction, and one in six had severe anaphylaxis. The major limitation of this study was the small number of patients recruited to the randomized controlled trial., Conclusion: Administration of antivenom in red-bellied black snake envenomation within 6 hours post-bite appeared to decrease the proportion of patients with myotoxicity, but a third of patients had adverse reactions.

Introduction: Myotoxicity is an important toxidrome that can occur with envenoming from multiple Australian snake types. Early antivenom administration is an important strategy to reduce the incidence and severity of myotoxicity. The current gold standard biomarker, serum creatine kinase activity, does not rise early enough to facilitate early antivenom administration. Several other skeletal muscle biomarkers have shown promise in other animal models and scenarios. The aim of this study was to examine the predictive values of six skeletal muscle biomarkers in a rat model of Australian snake myotoxicity., Methods: Sprague-Dawley rats were anaesthetised and administered either Pseudechis porphyriacus (red-bellied black snake) or Notechis scutatus (tiger snake) venom, or normal saline via intramuscular injection. Blood samples were collected. Assays were performed for serum creatine kinase skeletal muscle troponin-I concentration, skeletal muscle troponin-C concentration, myoglobin activity, skeletal muscle myosin light chain-1 concentration, and creatine kinase-MM activity. Serum markers were plotted against time, with comparison of area under the concentration (or activity)-time curve. The predictive values of six skeletal muscle biomarkers were examined using receiver operating characteristic curves., Results: There was no difference in area under the serum creatine kinase activity-time curve between venom and control groups. Serum creatine kinase-MM activity rose early in the venom treated rats, which had a significantly greater area under the serum activity-time curve. No difference in area under the serum concentration-time curve was demonstrated for the other biomarkers. Creatine kinase-MM activity had a superior predictive values than creatine kinase activity at 0-4 hours and 0-10 hours after venom administration, as indicated by area under the receiver operating characteristic curves (95 per cent confidence intervals) of 0.91 (0.78-1.00) and 0.88 (0.73-1.00) versus 0.79 (0.63-0.95) and 0.66 (0.51-0.80)., Discussion: The limitations of serum creatine kinase activity in early detection of myotoxicity were demonstrated in this rat model., Conclusion: Serum creatine kinase-MM activity was superior for early detection of Australian myotoxic snake envenoming.

The interplay between predator and prey has catalyzed the evolution of venom systems, with predators honing their venoms in response to the evolving resistance of prey. A previous study showed that the African varanid species Varanus exanthematicus has heightened resistance to snake venoms compared to the Australian species V. giganteus , V. komodoensis , and V. mertensi , likely due to increased predation by sympatric venomous snakes on V. exanthematicus . To understand venom resistance among varanid lizards, we analyzed the receptor site targeted by venoms in 27 varanid lizards, including 25 Australian varanids. The results indicate an active evolutionary arms race between Australian varanid lizards and sympatric neurotoxic elapid snakes. Large species preying on venomous snakes exhibit inherited neurotoxin resistance, a trait potentially linked to their predatory habits. Consistent with the 'use it or lose it' aspect of venom resistance, this trait was secondarily reduced in two lineages that had convergently evolved gigantism ( V. giganteus and the V. komodoensis / V. varius clade), suggestive of increased predatory success accompanying extreme size and also increased mechanical protection against envenomation due to larger scale osteoderms. Resistance was completely lost in the mangrove monitor V. indicus , consistent with venomous snakes not being common in their arboreal and aquatic niche. Conversely, dwarf varanids demonstrate a secondary loss at the base of the clade, with resistance subsequently re-evolving in the burrowing V. acanthurus / V. storri clade, suggesting an ongoing battle with neurotoxic predators. Intriguingly, within the V. acanthurus / V. storri clade, resistance was lost again in V. kingorum , which is morphologically and ecologically distinct from other members of this clade. Resistance was also re-evolved in V. glebopalma which is terrestrial in contrast to the arboreal/cliff dwelling niches occupied by the other members of its clade ( V. glebopalma , V. mitchelli , V. scalaris , V. tristis ). This 'Russian doll' pattern of venom resistance underscores the dynamic interaction between dwarf varanids and Australian neurotoxic elapid snakes. Our research, which included testing Acanthophis (death adder) venoms against varanid receptors as models for alpha-neurotoxic interactions, uncovered a fascinating instance of the Red Queen Hypothesis: some death adders have developed more potent toxins specifically targeting resistant varanids, a clear sign of the relentless predator-prey arms race. These results offer new insight into the complex dynamics of venom resistance and highlight the intricate ecological interactions that shape the natural world.

Abstract: Despite the in vivo lethality of venom, neurotoxicity has not previously been considered a significant complication of envenoming by the Australian pygmy copperhead (Austrelaps labialis). However, recent evidence has emerged demonstrating that this venom contains potent presynaptic and postsynaptic neurotoxicity. The present study describes the isolation and pharmacological characterization of the first postsynaptic neurotoxin, α-EPTX-Al2a, from the venom of A. labialis. α-EPTX-Al2a (8072.77Da) caused a concentration-dependent block of twitch contractions and a complete block of responses to cholinergic agonists in the chick biventer cervicis nerve–muscle preparation. This action is consistent with postjunctional neurotoxicity. Monovalent tiger snake antivenom prevented the onset of neurotoxicity if applied prior to toxin administration, but was only able to partially reverse neurotoxicity once muscle paralysis had developed. α-EPTX-Al2a produced a potent pseudo-irreversible antagonism of chick muscle nicotinic acetylcholine receptors (nAChRs), with an estimated pA2 value of 7.902 (K B =12.5nM). Interestingly, the toxin only produced a modest block of neuronal α7 nAChRs, with an IC50 of 1.2μM, and failed to inhibit ganglionic α3β2/α3β4 nAChRs in a fluorescence-based FLIPR assay using SH-SY5Y cells. α-EPTX-Al2a contained 75 amino acid residues with five disulfide bonds that had significant homology to classical long-chain α-neurotoxins. While α-EPTX-Al2a retains most pharmacophore residues critical for binding to muscle-type (α1)2βγδ nAChRs it lacks the key Ala28 and Arg36 residues important for α7 nAChR affinity. Given that A. labialis venom contains both irreversible presynaptic and postsynaptic neurotoxins, clinicians need to be aware of potential neurotoxic complications associated with pygmy copperhead envenomation. [Copyright &y& Elsevier]

Abstract: Pseudonaja textilis (Eastern Brown snake) and Oxyuranus scutellatus scutellatus (Coastal taipan) are clinically important Australian elapid snakes, whose potent venoms contain the presynaptic (β) neurotoxins, textilotoxin and taipoxin, respectively, and a number of postsynaptic neurotoxins. However, while taipan envenoming frequently results in neurotoxicity, Brown snake envenoming causes an isolated coagulopathy and neurotoxicity is rare. This phenomenon is called the ‘Brown snake paradox’. This study compared the pharmacology of both venoms and their respective presynaptic neurotoxins to investigate this phenomenon. From size-exclusion high performance liquid chromatography (HPLC) analysis textilotoxin represents a significantly smaller proportion (5.7%) of P. textilis venom compared to taipoxin in O. s. scutellatus venom (20.4%). In the chick biventer cervicis nerve-muscle (CBCNM) preparation both venoms caused concentration-dependent neurotoxicity, with P. textilis venom being significantly more potent than O. s. scutellatus venom. Conversely, taipoxin was significantly more potent than textilotoxin when compared at the same concentration. Textilotoxin only partially contributed to the overall neurotoxicity of P. textilis venom, while taipoxin accounted for the majority of the neurotoxicity of O. s. scutellatus venom in the CBCNM preparation. Compared with taipoxin, textilotoxin is less potent and constitutes a smaller proportion of the venom. This is likely to be the reason for the absence of neurotoxicity in envenomed humans thus explaining the ‘Brown snake paradox’. [Copyright &y& Elsevier]

Many prey species detect chemical cues from predators and modify their behaviours in ways that reduce their risk of predation. Theory predicts that prey should modify their anti-predator responses according to the degree of threat posed by the predator. That is, prey should show the strongest responses to chemicals of highly dangerous prey, but should ignore or respond weakly to chemicals from non-dangerous predators. However, if anti-predator behaviours are not costly, and predators are rarely encountered, prey may exhibit generalised antipredator behaviours to dangerous and non-dangerous predators. In Australia, most elapid snakes eat lizards, and are therefore potentially dangerous to lizard prey. Recently, we found that the nocturnal velvet gecko Oedura lesueurii responds to chemicals from dangerous and non-dangerous elapid snakes, suggesting that it displays generalised anti-predator behaviours to chemicals from elapid snakes. To explore the generality of this result, we videotaped the behaviour of velvet geckos in the presence of chemical cues from two small elapid snakes that rarely consume geckos: the nocturnal golden-crowned snake Cacophis squamulosus and the diurnal marsh snake Hemiaspis signata. We also videotaped geckos in trials involving unscented cards (controls) and cologne-scented cards (pungency controls). In trials involving Cacophis and Hemiaspis chemicals, 50% and 63% of geckos spent long time periods (> 3 min) freezing whilst pressed flat against the substrate, respectively. Over half the geckos tested exhibited anti-predator behaviours (tail waving, tail vibration, running) in response to Cacophis (67%) or Hemiaspis (63%) chemicals. These behaviours were not observed in control or pungency control trials. Our results support the idea that the velvet gecko displays generalised anti-predator responses to chemical cues from elapid snakes. Generalised responses to predator chemicals may be common in prey species that co-occur with multiple, ecologically similar, dangerous predators. [ABSTRACT FROM AUTHOR]

Many prey species use chemical cues to detect predators. According to the threat sensitivity hypothesis, prey should match the intensity of their antipredator behaviour to the degree of threat posed by the predator. Several species of lizards display antipredator behaviours in the presence of snake chemical cues, but how species specific are these responses? In Australia, most snake species eat lizards, and are therefore potentially dangerous. Hence, we predicted that lizards should display generalized rather than species-specific antipredator behaviours. To test this prediction, we quantified the behavioural responses of velvet geckos, Oedura lesueurii, to chemical cues from five species of elapid snakes that are syntopic with velvet geckos but differ in their degree of danger. These five snake species included two nocturnal ambush foragers that eat geckos (broad-headed snake Hoplocephalus bungaroides, and death adder, Acanthophis antarcticus), two active foragers that eat skinks (but rarely eat geckos) and that differ in their activity times (nocturnal small-eyed snake, Cryptophis nigrescens, and diurnal whip snake, Demansia psammophis), and a nocturnal nonthreatening species that feeds entirely on blind snakes (bandy-bandy, Vermicella annulata). Geckos showed similar antisnake behaviours (tail waving, tail vibration), and a similar intensity of responses (reducing activity, freezing), to chemical cues from all five snake species, even though the snakes differed in their degree of danger and foraging modes. Our results suggest that velvet geckos display generalized antipredator responses to chemicals from elapid snakes, rather than responding in a graded fashion depending upon the degree of threat posed by a particular snake species. [Copyright &y& Elsevier]

1. Ambush foragers that attract prey via luring provide an opportunity to examine how a predator's behaviour influences its dietary composition. 2. Australian death adders ( Acanthophis praelongus, Elapidae) are heavy-bodied ambush foragers with broad diets; the snake's modified tail-tip is waved to attract prey. Female adders have shorter tails than males, but longer terminal spines. 3. We videotaped captive snakes interacting with potential prey items (lizards and frogs) to document which prey types elicit luring, and which respond by approaching the lure. To clarify prey responses, we controlled lure size and colour by attaching snake tails (removed from dead adders) to a machine that waved the tail-tip in a manner similar to a live snake. 4. Individual adders differed in luring behaviour, and the type of tail-tip movement (undulatory vs. straightline) influenced rates and duration of luring bouts. 5. Lure movement was essential to attract lizards, and small lures were more effective than larger ones; the greater effectiveness of small lures may explain why caudal luring tends to be more common in juvenile snakes than in larger conspecifics. 6. Death adders lured more vigorously to lizards than to frogs, and lizards were more likely to approach the lure. Thus, luring in death adders mostly enables these snakes to capture lizards; frogs (also an important dietary component in the field) must be caught another way. 7. An ambush predator's overall dietary composition, as well as ontogenetic changes in that composition, thus depend upon both lure characteristics and prey responses. [ABSTRACT FROM AUTHOR]

One of the most prolific radiations of venomous snakes, the Australo-Melanesian Hydrophiinae includes ∼100 species of Australasian terrestrial elapids plus all ∼60 species of viviparous sea snakes. Here, we estimate hydrophiine relationships based on a large data set comprising 5800 bp drawn from seven genes (mitochondrial: ND4, cytb, 12S, 16S; nuclear: rag1, cmos, myh). These data were analysed using parsimony, likelihood and Bayesian methods to better resolve hydrophiine phylogeny and provide a timescale for the terrestrial and marine radiations. Among oviparous forms, Cacophis, Furina and Demansia are basal to other Australian elapids (core oxyuranines). The Melanesian Toxicocalamus and Aspidomorphus group with Demansia, indicating multiple dispersal events between New Guinea and Australia. Oxyuranus and Pseudonaja form a robust clade. The small burrowing taxa form two separate clades, one consisting of Vermicella and Neelaps calanotus, and the other including Simoselaps, Brachyurophis and Neelaps bimaculatus. The viviparous terrestrial elapids form three separate groups: Acanthophis, the Rhinoplocephalus group and the Notechis–Hemiaspis group. True sea snakes (Hydrophiini) are robustly united with the Notechis–Hemiaspis group. Many of the retrieved groupings are consistent with previous molecular and morphological analyses, but the polyphyly of the viviparous and burrowing groups, and of Neelaps, are novel results. Bayesian relaxed clock analyses indicate very recent divergences: the ∼160 species of the core Australian radiation (including sea snakes) arose within the last 10 Myr, with most inter-generic splits dating to between 10 and 6 Ma. The Hydrophis sea snake lineage is an exceptionally rapid radiation, with > 40 species evolving within the last 5 Myr. [ABSTRACT FROM AUTHOR]

Geographic divergence in phenotypic traits between long-isolated populations likely has a genetic basis, but can phenotypic plasticity generate such divergence rapidly in the initial stages of isolation? Australian tiger snakes ( Notechis scutatus, Elapidae) provide a classic model system for the evolution of body size: mean adult sizes are relatively invariant in mainland populations, but many offshore islands have dwarf or giant populations. Previous work has shown a genetic basis to this divergence in long-isolated islands (>10 000 years), but what of the initial stages of this process? Human translocation of mainland snakes to Carnac Island 90 years ago gives us a unique opportunity to assess the proximate reasons for the giant size of Carnac Island animals compared with mainland conspecifics. Our data suggest a major role for phenotypic plasticity. Feeding trials on captive snakes from both island and mainland populations showed a strong link between food intake and growth rates, similar in the two populations. Snakes given abundant food grew much larger than we have ever recorded in the wild, demonstrating that observed mean body sizes are driven by food availability rather than genetic limits to growth. In combination with earlier work showing genetic divergence in growth rates in snakes from long-isolated islands, our data suggest that geographical divergence in mean adult body sizes in this system initially is driven by a rapid shift due to phenotypic plasticity, with the divergence later canalized by a gradual accumulation of genetic differentiation. [ABSTRACT FROM AUTHOR]

Although forested habitats in eastern Australia have attracted significant conservation-related research, this work has focused strongly on endothermic vertebrates. Threatened reptile taxa have received less attention, but information on their habitat requirements should be central to management planning. The arboreal elapid snake Hoplocephalus stephensii is largely restricted to remnant forests in eastern Australia, and is listed as a threatened species under wildlife legislation. We collated 84 records of the current New South Wales geographical distribution of H. stephensii, and compared attributes of these locations to those of randomly chosen points within the same forests, in adjacent forests, in timber plantations and on freehold land across the geographical range of the taxon. Data on climatic and topographic characteristics of these sites were obtained from Geographic Information Systems databases and entered into a principal components analysis. Unsurprisingly, locations where snakes were recorded differed from the random sites in several respects (e.g. rainfall, elevation, seasonality of precipitation). Within a given forest, H. stephensii was generally found in areas similar to randomly chosen points. Comparison of vegetation communities used with those available within forests provided no evidence for active habitat selection. Comparisons of Geographic Information Systems-derived data for snake-collection localities along roads versus those within the forest revealed significant biases, and we warn that such methodological errors could generate spurious conclusions about non-random habitat use by threatened species. In combination with previous data from radio-tracking, we conclude that although H. stephensii is highly specialized in its arboreality and dependence upon hollow trees, its broad tolerance with respect to other factors (climatic conditions, vegetation communities, food types, etc.) allows populations to persist so long as large areas of forest with high numbers of hollow-bearing trees are available. These requirements are similar to those of many other components of the Australian forest fauna. Thus, the findings of this study support the idea that the same kinds of management programmes can effectively conserve a wide range of taxa, if such programmes protect critical habitat components at suitable spatial scales. [ABSTRACT FROM AUTHOR]

Brown snakes, Pseudonaja genus, cause more bites and deaths to animals and humans in Australia than any other terrestrial snake genus. Some aspects of treatment of brown snakebites with antivenom remain poorly managed due to the apparent inability of the antivenom to counter the prothrombin activator in the venom. We present evidence of a new novel antivenom (Antiven Pty Ltd Brown snake antivenom (ABSAV)), which shows high efficacy in reversing the hemostatic abnormality caused by brown snake envenomation. It is also more efficient at reversing overall toxicity. In clotting tests, it is substantially more potent than Commonwealth Serum Laboratories Ltd (CSL) Brown snake antivenom and is twice as effective in reversing overall toxicity than CSL Brown snake antivenom. Antiven Pty. Ltd. Brown snake antivenom is currently being assessed by the National Registration Authority (veterinary regulative body in Australia). [ABSTRACT FROM AUTHOR]

Vertebral and cranial remains of elapid snakes have been collected from fossil assemblages at Riversleigh, north-west Queensland, Australia; most are Miocene but one may be late Oligocene and another as young as Pliocene. The oldest specimen (probably the oldest elapid yet known anywhere) is a vertebra that can be referred provisionally to the extant taxon Laticauda (Hydrophiinae, sensu ), implying that the basal divergences among Australasian hydrophiine lineages had occurred by the early Miocene, in contrast to most previous estimates for the age of this geographically isolated adaptive radiation. Associated vertebrae and jaw elements from a Late Miocene deposit are described as Incongruelaps iteratus nov. gen. et sp., which has a unique combination of unusual derived characters otherwise found separately in several extant hydrophiine taxa that are only distantly related. Associated vertebrae from other sites, and two parietals from a possibly Pliocene deposit, suggest the presence of several other taxa distinct from extant forms, but the amount of material (and knowledge of variation in extant taxa) is currently insufficient to diagnose these forms. The Tertiary elapids of Riversleigh thus appear to be relatively diverse taxonomically, but low in abundance and, with one exception, not referable to extant taxa below the level of Hydrophiinae. This implies that the present diversity of hydrophiine elapids (31 recognized terrestrial genera, and approximately 16 marine) represents the result of substantial extinction as well as the “cone of increasing diversity” that could be inferred from phylogenetic studies on extant forms. [Copyright &y& Elsevier]

Investigates the aquatic and terrestrial locomotion of sea snakes Laticauda colubrina in Australia. Locomotor performance of three species of Australian terrestrial elapids; Locomotor ability of proteroglyphous snakes.

We studied the neutralisation of Sri Lankan Russell's viper ( Daboia russelii ) and Australian mulga snake ( Pseudechis australis ) venom-induced myotoxicity by Indian (Vins and Bharat) and Australian (Seqirus) polyvalent antivenoms, using the in vitro chick biventer skeletal muscle preparation. Prior addition of Bharat or Vins antivenoms abolished D. russelii venom (30 µg/mL)-mediated inhibition of direct twitches, while Australian polyvalent antivenom was not protective. Bharat antivenom prevented, while Vins and Australian polyvalent antivenoms partially prevented, the inhibition of responses to exogenous KCl. Myotoxicity of Mulga venom (10 µg/mL) was fully neutralised by the prior addition of Australian polyvalent antivenom, partially neutralised by Vins antivenom but not by Bharat antivenom. Although the myotoxicity of both venoms was partially prevented by homologous antivenoms when added 5 min after the venom, with an increasing time delay between venom and antivenom, the reversal of myotoxicity gradually decreased. However, antivenoms partially prevented myotoxicity even 60 min after venom. The effect of antivenoms on already initiated myotoxicity was comparable to physical removal of the toxins by washing the bath at similar time points, indicating that the action of the antivenoms on myotoxicity is likely to be due to trapping the toxins or steric hindrance within the circulation, not allowing the toxins to reach target sites in muscles.

Despite antivenoms being the only established specific treatment for neuromuscular paralysis arising from snake envenoming, their ability to reverse the post-synaptic neurotoxicity in snake envenoming is poorly understood. We investigated the ability of five commercial antivenoms i.e., King cobra monovalent, Thai cobra monovalent, Thai neuro polyvalent, Indian polyvalent and Australian polyvalent antivenoms to reverse neurotoxicity induced by the venoms of King cobra ( Ophiophagus hannah , 3 µg/mL), Indian cobra (Naja naja , 5 µg/mL) and Thai cobra ( Naja kaouthia , 3 µg/mL) using the in vitro chick-biventer cervicis nerve-muscle preparation. All three venoms displayed post-synaptic neurotoxicity, which was prevented by all tested antivenoms (40 µL/mL) added to the bath prior to venom. All antivenoms partially reversed the established post-synaptic neuromuscular block after the addition of the three venoms during a 180 min observation period, but to varying degrees and at different rates. The neurotoxic effects of O. hannah venom recovered to a greater magnitude (based on twitch height restoration) and faster than the neurotoxicity of N. kaouthia venom, which recovered to a lower magnitude more slowly. The recovery of post-synaptic neurotoxicity by N. naja venom was hindered due to the likely presence of cytotoxins in the venom, which cause direct muscle damage. The observations made in this study provide further evidence that the commercial antivenoms are likely to actively reverse established α-neurotoxin-mediated neuromuscular paralysis in snake envenoming, and there is cross-neutralisation with different antivenoms.

Background: Snakebite-associated thrombotic microangiopathy (TMA) occurs in a subset of patients with venom-induced consumption coagulopathy (VICC) following snakebite. Acute kidney injury (AKI) is the commonest end-organ manifestation of TMA. The epidemiology, diagnostic features, outcomes, and effectiveness of interventions including therapeutic plasma-exchange (TPE), in snakebite-associated TMA are poorly understood., Methods: We reviewed all patients with suspected or confirmed snakebite recruited to the Australian Snakebite Project (2004-2018 inclusive), a prospective cohort study, from 202 participating Australian hospitals across the country. TMA was defined as anemia with schistocytosis., Results: 2069 patients with suspected snakebite were enrolled, with 1158 (56.0%) systemically envenomed, of which 842 (72.7%) developed VICC, from which 104 (12.4%) developed TMA. Of those systemically envenomed, TMA occurred in 26% (13/50) taipan, 17% (60/351) brown, and 8% (16/197) tiger snakebites. Thrombocytopenia was present in 90% (94/104) of TMA cases, and a further eight (8%) had a > 25% decrease in platelets from the presentation. Patients with TMA were significantly older than non-TMA patients with VICC (53 [35-61] versus 41 [24-55] years, median [IQR], p  < 0.0001). AKI developed in 94% (98/104) of TMA patients, with 34% (33/98) requiring dialysis (D-AKI). There were four deaths. In D-AKI TMA cases, eventual dialysis-free survival (DFS) was 97% (32/33). TPE was used in five D-AKI cases, with no significant difference in DFS or time to independence from dialysis. >90-day follow-up for 25 D-AKI cases (130 person-years) showed no end-stage kidney disease but 52% (13/25) had ≥ stage 3 chronic kidney disease (CKD)., Conclusion: Our findings support a definition of snakebite-associated TMA as anemia with schistocytosis and either thrombocytopenia or >25% drop in platelet count. AKI occurring with snakebite-associated TMA varied in severity, with most achieving DFS, but with a risk of long-term CKD in half. We found no evidence of benefit for TPE in D-AKI.

Examines the cDNA cloning, expression and protein characterization on postsynaptic short-chain neurotoxins from Pseudonaja textilis in Australia. Isolation of proteins on short-chain neurotoxins; Use of RT-PCR of the venom gland messenger RNA to clone neurotoxins; Characteristics of postsynaptic neurotoxins from the venom of elapid.

Transposable elements (TEs) are self-replicating genetic sequences and are often described as important 'drivers of evolution'. This driving force is because TEs promote genomic novelty by enabling rearrangement, and through exaptation as coding and regulatory elements. However, most TE insertions potentially lead to neutral or harmful outcomes, therefore host genomes have evolved machinery to suppress TE expansion. Through horizontal transposon transfer (HTT) TEs can colonize new genomes, and since new hosts may not be able to regulate subsequent replication, these TEs may proliferate rapidly. Here, we describe HTT of the Harbinger-Snek DNA transposon into sea kraits ( Laticauda ), and its subsequent explosive expansion within Laticauda genomes. This HTT occurred following the divergence of Laticauda from terrestrial Australian elapids approximately 15-25 Mya. This has resulted in numerous insertions into introns and regulatory regions, with some insertions into exons which appear to have altered UTRs or added sequence to coding exons. Harbinger-Snek has rapidly expanded to make up 8-12% of Laticauda spp. genomes; this is the fastest known expansion of TEs in amniotes following HTT. Genomic changes caused by this rapid expansion may have contributed to adaptation to the amphibious-marine habitat.

Despite recent reviews of best practice for the treatment of Australian venomous bites and stings, there is controversy about some aspects of care, particularly the use of antivenom. Our aim was to understand current attitudes and practice in the management of suspected snake envenoming. A single-stage, cross-sectional survey of Australian emergency care physicians who had treated snake envenomation in the previous 36 months was conducted. Hospital pharmacists were also invited to complete a survey about antivenom availability, usage, and wastage in Australian hospitals. The survey was available between 5 March and 16 June 2019. A total of 121 snake envenoming cases were reported, and more than a third (44.6%) of patients were not treated with antivenom. For those treated with antivenom ( n = 67), 29 patients (43%) received more than one ampoule. Nearly a quarter of respondents (21%) identified that antivenom availability was, or could be, a barrier to manage snake envenoming, while cost was identified as the least important factor. Adverse reactions following antivenom use were described in 11.9% of cases ( n = 8). The majority of patients with suspected envenoming did not receive antivenom. We noted variation in dosage, sources of information, beliefs, and approaches to the care of the envenomed patient.

Black snakes (Pseudechis spp) are a genus of venomous Australian elapid snakes that can cause major clinical envenomation in companion animals, which may be fatal, even with appropriate antivenom treatment. Despite its clinical significance, there is little published information on the pathology of black snake envenomation. We report the gross and microscopic lesions associated with black snake envenomation in two dogs, one with a definitive immunological species identification of red-bellied black snake (RBBS; Pseudechis porphyriacus), the other with a black snake immunotype on a venom detection kit. Both dogs were located in a geographical area where the RBBS is found. The prominent gross findings in both cases included icterus, localized facial oedema in the region of the presumed bite wound, pigmenturia and multicavitary serosanguineous effusions. Histopathology of the confirmed RBBS case revealed acute renal tubular necrosis with haemosiderosis, marked splenic haemosiderosis and centrilobular to midzonal hepatocellular necrosis with severe cholestasis. Defining the spectrum of lesions of elapid snake envenomation improves understanding of the pathogenesis, which may lead to improved patient outcomes and post-mortem diagnosis., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

This report documents the clinicopathological features of cutaneous chromatophoromas in four wild-caught, captive Australian elapid snakes: a strap-snouted brown snake (Pseudonaja aspidoryncha), a tiger snake (Notechis scutatus), an Eastern brown snake (Pseudonaja textilis) and a Mengden's brown snake (Pseudonaja mengdeni). All tumours were subclassified as melanophoromas, with three assessed as malignant on the basis of invasive growth or presence of intracoelomic metastases. The chromatophoromas were single or multiple, black or orange pigmented, cutaneous, sometimes ulcerated, plaques or nodules. Microscopically, the neoplastic cells were often spindle shaped with low or variable pigmentation. Neoplastic cells in one tumour were notable for their pleomorphic round cell morphology and high mitotic rate. One snake with late-stage metastasis survived for over 5 years. There are few reports of chromatophoromas in elapid snakes and, to our knowledge, this is the first report of these tumours in Australian elapid snakes., (Copyright © 2020. Published by Elsevier Ltd.)

SnakeMap is a national cloud-based, veterinary snakebite registry. It was designed to prospectively collect data of the clinical circumstances and temporospatial information on cases of snake envenomation in dogs and cats. We herein introduce the project and summarise the data from the first 4 years of SnakeMap. The registry is a veterinary community-based online database allowing case entry from veterinary hospitals across Australia. Registry data comprise hospital characteristics, patient characteristics, envenoming snake type, treatment and outcome variables, including time and geolocation of the snake bite. We present summative information on select key variables from the SnakeMap registry (1 July 2015 to 30 June 2019). Twenty-eight hospitals from 6 states/territories entered 624 cases into the registry, including 419 dogs (67%) and 205 cats (33%). Bite time was available in 216 animals of which 90 (42%) were reported to be bitten in the 3 hours between 03:00 pm and 05:59 pm; median bite to presentation interval was 60 (interquartile range [IQR] 30, 211) minutes in dogs and 95 (IQR 41, 238) minutes in cats. Bites occurred in the owner's yard in 356 dogs (85%) and 53 cats (26%). A snake venom detection kit was used in 172 cases (28%) and antivenom was administered in 523 cases (85%). Most animals (n = 534, 88%) survived to discharge (median hospitalisation of 25 [IQR 16, 62] hours). SnakeMap effectively collects relevant clinical data from dogs and cats with presumed snake bite and provides locally specific information on the epidemiology of snake envenomation in small animals., (© 2020 Australian Veterinary Association.)

Because the median dose of one vial 'clears the blood of circulating venom', the authors of the Australian Snakebite Project recommend restriction of antivenom to one vial for all envenomated victims. This is neither scientific nor safe. Methodological flaws in the case series include limited detection of venom toxins and misinterpretation of data. The recommendation fails to consider larger doses of venom than that neutralised by one vial of antivenom. Although one vial may be adequate for minor envenomation, the initial dose should be two vials with more on a clinical basis.

We want to discuss antivenom use in snakebite clinical practice guidelines. Coronial reviews in Victoria of two cases of snakebite envenomation, one described in detail below, prompted us to submit this paper for a wider audience and debate. Venom and antivenom levels were measured in the case detailed below, but not in the other. The coroner received conflicting and varied advice from experts regarding the dose of antivenom. The Victorian Department of Health and Human Services and the Australasian College for Emergency Medicine were instructed to review snakebite management guidelines, particularly with respect to antivenom dosage. The discussion that took place among medical experts led to considerable media attention. We discuss the potential fallout when there is no consensus among medical experts., (© 2019 Australasian College for Emergency Medicine.)

Bandy-bandies (genus Vermicella) are small (50-100cm) black and white burrowing elapids with a highly specialised diet of blindsnakes (Typhlopidae). There are currently 5 recognized species in the genus, all located in Australia, with Vermicella annulata the most encountered species with the largest distribution. Morphological and mitochondrial analyses of specimens collected from the Weipa area, Cape York, Queensland reveal the existence of a new species, which we describe as Vermicella parscauda sp. nov. Mitochondrial DNA analysis (16S and ND4) and external morphological characteristics indicate that the closest relatives of the new species are not V. annulata, which also occurs on Cape York, but rather species from Western Australia and the Northern Territory (V. intermedia and V. multifasciata) which, like V. parscauda, occupy monsoon habitats. Internasal scales are present in V. parscauda sp. nov., similar to V. annulata, but V. intermedia and V. multifasciata do not have nasal scales. V. parscauda sp. nov. has 55-94 black dorsal bands and mottled or black ventral scales terminating approximately 2/3rds of the body into formed black rings, suggesting that hyper-banding is a characteristic of the tropical monsoon snakes (V. intermedia, V. multifasciata and V. parscauda). The confined locality, potential habitat disruption due to mining activities, and scarcity of specimens indicates an urgent conservation concern for this species.

Snakebite in dogs from Pseudechis porphyriacus (red-bellied black snake; RBBS) is a common envenomation treated by veterinarians in Australia where this snake occurs. This case report describes the successful treatment of a clinically severe RBBS envenomation in a dog with an experimental bivalent equine whole IgG antivenom and mechanical ventilation, following its presentation in a cyanotic state. The cause of the cyanosis and respiratory distress was considered due to paralysis from neurotoxins in RBBS venom. The dog was treated with two vials of bivalent antivenom, each containing sufficient antivenom to neutralise the lethal effects of 40 mg of tiger snake (Notechis sp) and 40 mg of brown snake (Pseudonaja sp) venom. Hypoxaemia (Sp0 2 of 75%) and hypercapnia (PaCO 2 of 61 mmHg) indicated the need for mechanical ventilation (MV) to prevent imminent death. The dog was anaesthetised using total intravenous anaesthesia and MV used for 18 h. Following discontinuation of MV, it resumed spontaneous breathing thereafter and made a complete recovery. Serum biochemistry revealed a significant myopathy with elevated CK and AST levels, peaking approximately 48 h post-treatment. Elevated liver enzymes, suggestive of hypoxic liver injury, were detected during the period of hospitalisation. The dog represented approximately one week after hospital discharge because of inappetence and mild hepatopathy, which resolved spontaneously by 30 d post-treatment. A mild coagulopathy was initially present which resolved within 24 h following antivenom treatment. At initial presentation, RBBS venom antigen was detected by sandwich ELISA in urine and serum. Free RBBS venom antigen was not detected post-antivenom treatment. Human cases of RBBS requiring ventilatory support are rare. This unusual case of RBBS envenomation in a dog highlights its potential clinical severity in dogs, and the need for early, aggressive, MV to achieve a successful outcome in cyanosed and clinically severe cases., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Context: Many bites from mildly venomous elapids occur but identification or presence of systemic envenoming is rarely confirmed., Objective: To confirm systemic envenoming and binding of venom components to a commercial antivenom in a definite bite by the Ornamental Snake (Denisonia maculata) using enzyme immunoassays., Case: A 9-year old boy was bitten by an identified Ornamental Snake. He developed nausea, vomiting, local pain, and swelling. He had a leucocytosis (white cell count, 20.8 × 10(9)/L), an elevated international normalised ratio (INR) of 1.6, but otherwise normal blood tests including D-Dimer and activated partial thromboplastin time. He was treated with Australian Black Snake antivenom because the commercial venom detection kit was positive for Black snake. He was admitted for 36 h with continuing local pain and swelling requiring parenteral analgesia., Materials and Methods: Blood samples were collected with informed consent for measurement of venom and antivenom concentrations. Venom-specific enzyme immunoassays were developed using the closely related D. devisi venom with Rabbit anti-Notechis (Tiger Snake) and anti-Tropidechis (Rough-scaled Snake) IgG antibodies to detect venom in serum. Standard curves for measured venom versus actual venom concentrations were made to interpolate Denisonia venom concentrations. In vitro procoagulant and anticoagulant activity of venom was assayed., Results: Denisonia venom was detected in the pre-antivenom sample as 9.6 ng/mL D. devisi venom. No antigenic venom components were detected in post-antivenom samples and there were high antivenom concentrations. D. devisi venom had mild in vitro procoagulant activity with a minimum concentration required to clot after 5 min of 2.5-5 μg/mL and even weaker anticoagulant activity., Conclusions: Denisonia bites appear to cause local effects and possibly mild systemic envenoming (with only non-specific systemic symptoms and leucocytosis), confirmed by detection of antigenic venom components in blood. A significant coagulopathy does not appear to occur.

Brown snake (Pseudonaja spp.)-induced early cardiovascular collapse is a life-threatening medical emergency in Australia. We have previously shown that this effect can be mimicked in animals and is mediated via the release of endogenous mediators. In the present study, we aimed to purify and characterize the component in Pseudonaja textilis venom which induces cardiovascular collapse following envenoming. The component (fraction 3) was isolated using a combination of techniques including hydroxyapatite and reverse phase chromatography. Fraction 3 (10 or 20 μg/kg, i.v.) produced a rapid decrease in mean arterial pressure (MAP) followed by cardiovascular collapse. Fraction 3-induced early collapse was abolished by prior administration of smaller priming doses of fraction 3 (i.e. 2 and 5 μg/kg, i.v.) or heparin (300 units/kg, i.v.). P. textilis whole venom (1 and 3 μg/ml), but not fraction 3 (1 or 3 μg/ml), induced endothelium-dependent relaxation in isolated rat mesenteric arteries. SDS-PAGE gel indicated the presence of 9-10 protein bands of fraction 3. Using proteomic based analysis some protein bands of fraction 3 were identified as subunits of venom prothrombin activator, pseutarin C of P. textilis venom. Our results conclude that prothrombin activator-like toxin is likely to be a contributor to the rapid collapse induced by P. textilis venom., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: Venom-induced consumption coagulopathy (VICC) is an important feature of snake envenoming. Aim: To investigate the effect of antivenom and fresh frozen plasma (FFP) on recovery of VICC in Australian elapid snake envenoming. Design: Prospective cohort study. Methods: Patients with VICC were included from the Australian Snakebite Project (ASP). Time to recovery of VICC (defined as time until INR <2) was investigated using a time to event analysis in WinBUGS. The model considered the effects of age, sex, snake type, time of antivenom after bite, antivenom dose and use of FFP within 4 h. Results: The study included 167 cases of VICC, median age being 41 [interquartile range (IQR): 28–53) years, and 130 (78%) were males. Antivenom was administered at a median of 3.6 (IQR: 2.2–5.6) h after the bite at a median dose of four vials (IQR: 2–6 vials). Thirteen patients received FFP within 4 h. Recovery of VICC occurred after a median of 14.4 (IQR: 11.5–17.5) h, and only the use of FFP within 4 h influenced the time to recovery. Neither antivenom dose nor time of antivenom administration had an effect on recovery of VICC. In patients administered with FFP, 12% [credible interval (CrI): 6–21%] and 81% (CrI: 61–94%) had recovered at 6 and 12 h, respectively, vs 2.5% (CrI: 1.5–4%) and 28% (CrI: 22–34%) not receiving FFP. Discussion: Antivenom did not appear to be effective for the coagulopathy in snake envenoming in Australia. FFP appeared to shorten the time of VICC recovery. [ABSTRACT FROM AUTHOR]

Antivenoms manufactured by bioCSL Limited (Australia) and Instituto Clodomiro Picado (Costa Rica) against the venom of the taipan snakes (Oxyuranus scutellatus) from Australia and Papua New Guinea (PNG), respectively, were compared using antivenomics, an analytical approach that combines proteomics with immunoaffinity chromatography. Both antivenoms recognized all venom proteins present in venom from PNG O. scutellatus, although a pattern of partial recognition was observed for some components. In the case of the Australian O. scutellatus venom, both antivenoms immunorecognized the majority of the components, but the CSL antivenom showed a stronger pattern of immunoreactivity, which was revealed by the percentage of retained proteins in the immunoaffinity column. Antivenoms interacted with taipoxin in surface plasmon resonance. These observations on antivenomics agree with previous neutralization studies., (© The American Society of Tropical Medicine and Hygiene.)

Background: The mulga snake (Pseudechis australis) is the largest terrestrial venomous snake in Australia. It is capable of inflicting severe and occasionally fatal envenoming, but there have been few studies of P. australis bites., Objectives: To highlight and reinforce the main features of P. australis envenoming and to provide a clearer picture of the epidemiology of bites from this species., Methods: Selected case records kept by the Toxinology Dept. (Women's and Children's Hospital, Adelaide, Australia) were reviewed retrospectively to determine definite P. australis bites., Inclusion Criteria: definite cases where the snake was identified by a competent person and/or lab specimens (bite site/urine) tested positive for "black snake" using CSL snake venom detection kit in a locality within the known range of P. australis, but without sympatry with other Pseudechis spp., Exclusion Criteria: where the snake could not be clearly identified under criteria above. Epidemiological and clinical information was recorded and analysed for the definite cases., Results: A total of 27 cases were identified as definite P. australis bites; there were no fatalities. The median age was 35.5 years (IQR 51-23) and 80% of bites occurred in males. More bites occurred in the warmer months (Dec-March) and in those handling/interfering with snakes. Seven people were bitten whilst asleep at night. 21/27 patients developed systemic envenoming (based on signs, symptoms and laboratory results) and 17 cases received antivenom. Local bite site pain (18) and swelling (17) were common as were non-specific generalised symptoms such as nausea, vomiting and headache. Myotoxicity (11) and anticoagulant coagulopathy (10) occurred frequently; haemolysis was seen in fewer cases (3). Two patients developed local tissue injury around the bite site requiring further treatment., Conclusions: This study confirms previous reports about P. australis bites with respect to high rates of envenoming, commonly associated with pain and swelling and systemic effects of rhabdomyolysis and anticoagulant coagulopathy. Systemic envenoming, even severe cases, responds well to antivenom therapy. Compared to other Australian snakes, a high proportion of bites occur in people asleep at night. Medically significant local tissue injury around the bite site may occur and may be associated with inappropriate first-aid, particularly the vascular occlusive type., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Snakebite is a potential medical emergency and must receive high-priority assessment and treatment, even in patients who initially appear well. Patients should be treated in hospitals with onsite laboratory facilities, appropriate antivenom stocks and a clinician capable of treating complications such as anaphylaxis. All patients with suspected snakebite should be admitted to a suitable clinical unit, such as an emergency short-stay unit, for at least 12 hours after the bite. Serial blood testing (activated partial thromboplastin time, international normalised ratio and creatine kinase level) and neurological examinations should be done for all patients. Most snakebites will not result in significant envenoming and do not require antivenom. Antivenom should be administered as soon as there is evidence of envenoming. Evidence of systemic envenoming includes venom-induced consumption coagulopathy, sudden collapse, myotoxicity, neurotoxicity, thrombotic microangiopathy and renal impairment. Venomous snake groups each cause a characteristic clinical syndrome, which can be used in combination with local geographical distribution information to determine the probable snake involved and appropriate antivenom to use. The Snake Venom Detection Kit may assist in regions where the range of possible snakes is too broad to allow the use of monovalent antivenoms. When the snake identification remains unclear, two monovalent antivenoms (eg, brown snake and tiger snake antivenom) that cover possible snakes, or a polyvalent antivenom, can be used. One vial of the relevant antivenom is sufficient to bind all circulating venom. However, recovery may be delayed as many clinical and laboratory effects of venom are not immediately reversible. For expert advice on envenoming, contact the National Poisons Information Centre on 13 11 26.