Envenomation

Mortality due to snake envenomation is not a major problem in the United States with approximately 8–12 deaths per year, but envenomation is a serious problem that can result in functional disability, loss of extremities, and a costly recovery. Physicians encounter different clinical situations with each new snakebite victim because of the geographical variations in snake venoms. The best and most acceptable form of treatment is the use of antivenom; however, it must be administered as soon as possible since it is not so effective at reducing local signs of envenomation such as necrosis. The antivenom in the United States is in short supply, expensive and may not even be the most effective for neutralizing all North American snake venoms. In this study, we tested two antivenoms. The first was a Crotalidae Polyvalent Fab fragment with Ovine origin (FabO) manufactured in London, and the second was Antivipmyn, a Mexican manufactured antivenom that is F(ab′)2 fragment produced in horse (Fab2H). The efficacy of the two antivenoms was tested with 15 different snake venoms found in North America. Three different assays were used to test the efficacy of the antivenoms, the in vivo serum protection test (ED50), antihemorrhagic and anticoagulant. The Fab2H antivenom was most effective in neutralizing the hemorrhagic activity of 78% of the hemorrhagic venoms used in this study. In the ED50 assay, the Fab2H antivenom was effective in neutralizing all venoms used in this study, while FabO neutralized all but C. m. molossus venom. However, in most cases, FabO required less antivenom than Fab2H antivenom to neutralize three LD50.

Cnidarian envenomations are the leading cause of severe and lethal human sting injuries from marine life. The total amount of venom discharged into sting-site tissues, sometimes referred to as " venom load " , has been previously shown to correlate with tentacle contact length and sequelae severity. Since <1% of cnidae discharge upon initial tentacle contact, effective and safe removal of adherent tentacles is of paramount importance in the management of life-threatening cubozoan stings. We evaluated whether common rinse solutions or scraping increased venom load as measured in a direct functional assay of venom activity (hemolysis). Scraping significantly increased hemolysis by increasing cnidae discharge. For Alatina alata, increases did not occur if the tentacles were first doused with vinegar or if heat was applied. However, in Chironex fleckeri, vinegar dousing and heat treatment were less effective, and the best outcomes occurred with the use of venom-inhibiting technologies (Sting No More ® products). Seawater rinsing, considered a " no-harm " alternative, significantly increased venom load. The application of ice severely exacerbated A. alata stings, but had a less pronounced effect on C. fleckeri stings, while heat application markedly reduced hemolysis for both species. Our results do not support scraping or seawater rinsing to remove adherent tentacles.

The seas and oceans around Australia harbour numerous venomous jellyfish. Chironex fleckeri, the box jellyfish, is the most lethal causing rapid cardiorespiratory depression and although its venom has been characterised, its toxins remain to be identified. A moderately effective antivenom exists which is also partially effective against another chirodropid, Chiropsalmus sp. Numerous carybdeids, some unidentified, cause less severe illness, including Carybdea rastoni whose toxins CrTX-A and CrTX-B are large proteins. Carukia barnesi, another small carybdeid is one cause of the &#39;Irukandji&#39; syndrome which includes delayed pain from severe muscle cramping, vomiting, anxiety, restlessness, sweating and prostration, and occasionally severe hypertension and acute cardiac failure. The syndrome is in part caused by release of catecholamines but the cause of heart failure is undefined. The venom contains a sodium channel modulator. Two species of Physalia are present and although one ...

Cubozoa-class cnidarian (box jellyfi sh) envenomations constitute a complex medical challenge and public health threat. There are currently no validated standards of care for life-threatening stings. Increasing numbers and reported geographic ranges of serious cubozoan envenomations underscore the urgent need for mechanism-based emergency therapeutic options for lifeguards, fi rst responders and clinicians. For the most part, treatment and management approaches have been symptom-driven, utilizing therapeutics familiar to the practitioner and often based on extrapolation from other envenomation sequelae, rather than cubozoan-specifi c standardized protocols. Newly elucidated mechanisms of pathogenesis provide a context for directed clinical research to test novel therapeutic approaches that could greatly diminish human suffering and improve outcomes. The current state of our understanding about the pathophysiology of cnidarian envenomation and emerging therapeutic options for the medically relevant cubozoans will be presented.

South and Southeast Asia and Latin American together comprise 46 countries and are home to approximately 40% of the world population. The sociopolitical and economic heterogeneity, tropical climate, and malady transitions characteristic of the region strongly influence disease behavior and health care delivery. Acute kidney injury epidemiology mirrors these inequalities. In addition to hospital-acquired acute kidney injury in tertiary care centers, these countries face a large preventable burden of community-acquired acute kidney injury secondary to tropical infectious diseases or animal venoms, affecting previously healthy young individuals. This article reviews the epidemiology, clinical picture, prevention, risk factors, and pathophysiology of acute kidney injury associated with tropical diseases (malaria, dengue, leptospirosis, scrub typhus, and yellow fever) and animal venom (snakes, bees, caterpillars, spiders, and scorpions) in tropical regions of Asia and Latin America, and discusses the potential future challenges due to emerging issues.

The polyphyletic family Colubridae contains approximately
two-thirds of the described species of advanced snakes, and
nearly half of these (approx. 700 species) produce a venom in a specialized cephalic gland, the Duvernoy’s gland. Biochemical and pharmacological information is lacking for venoms of most species, and modest detailed information on venom composition is available for only a few species which represent a potential health threat to humans. However, colubrid venoms represent a vast source of novel compounds, and some toxins, such as the 20–26 kD CRISP-related venom proteins (helveprins), have only recently been identified in both colubrid and elapid/viperid venoms. Difficulties associated with extraction have been addressed, and it is now possible to obtain venom sufficient for many analyses from even small species. There appears to be a greater number of venom components shared among the colubrids
and the front-fanged snakes than has been previously
noted, and it is probable that as analytical methods improve,
more similarities will emerge. It is clear that colubrid venoms
are homologous with front-fanged snake venoms, but overall
composition as well as biological role(s) of colubrid venoms
may be quite different. Metallo- and serine proteases have been identified in several colubrid venoms, and phospholipase A2 is a more frequent component than has been previously recognized. Venom phosphodiesterase, acetylcholinesterase and prothrombin activator activities occur in some venoms, and postsynaptic neurotoxins and myotoxins have been partially characterized for venoms from several species. Some venoms show high toxicity toward inbred mice, and others are toxic to birds and/or frogs only. Because many colubrids feed on non-mammalian prey, lethal toxicity toward mice is likely only relevant as a measure of potential risk posed to humans. Development of a non-mammalian vertebrate animal model would greatly facilitate systematic comparisons of the pharmacology of colubrid venoms and their components, and such a model would be more appropriate for evaluation of colubrid venom toxicity. Proteomics has the potential to increase our understanding of these venoms rapidly, but classical approaches to toxinology can also contribute
tremendously to this understudied field. As more colubrid
venoms are analyzed, new compounds unique to colubrid
venoms will be identified, and this work in turn will lead to a
better understanding of the evolution and biological significance of snake venoms and venom components.

Centipedes are among the oldest extant venomous predators on the planet. Armed with a pair of modified, venom-bearing limbs, they are an important group of predatory arthropods and are infamous for their ability to deliver painful stings. Despite this, very little is known about centipede venom and its composition. Advances in analytical tools, however, have recently provided the first detailed insights into the composition and evolution of centipede venoms. This has revealed that centipede venom proteins are highly diverse, with 61 phylogenetically distinct venom protein and peptide families. A number of these have been convergently recruited into the venoms of other animals, providing valuable information on potential underlying causes of the occasionally serious complications arising from human centipede envenomations. However, the majority of venom protein and peptide families bear no resemblance to any characterised protein or peptide family, highlighting the novelty of centipe...

Effective antitussives available to control cough are limited. Consolidation among different afferent branches of the vagus nerve is needed to bring about cough. A general, widely accepted view is that the chronic increase in the sensitivity of the cough reflex is associated with inflammatory hypersensitivity such as from gastro-esophageal reflux disease. There is increasing evidence that an important mechanism is a sensory disorder of the laryngeal branches of the vagus nerve. Neuromodulating drugs are effectively used in the treatment of chronic pain and neuropathic disorders and may have a role in the treatment of refractory chronic cough (CC). Current evidence on the efficacy and safety of gabapentin in the treatment of CC is reviewed. Relevant randomized controlled trials, case reports and reviews were identified through a PubMed search of English-language literature referring to cough, sensory neuropathy and gabapentin over the last 10 years. Gabapentin appears to be effective...

We report the case of a 65-year-old woman who presented with severe neurologic complications after envenomation by a viper snake. A computed tomography (CE) scan revealed multiple brain hemorrhagic infarcts. Conservative treatment in this case proved to be sufficient and repetitive CT scans displayed a complete resolution of the radiologic findings. Possible mechanisms for the cerebral infarctions are discussed. The mechanism of infarctions in this case was believed to be the vasomotor and coagulation disorders caused by the toxins present in the snake&#39;s venom and was one of the reasons that led to conservative treatment.

The WHO has identified the goal of halving deaths and disability from snakebite envenomation (SBE) by 2030 through a four-pillar program that promotes accessible and affordable treatments, strengthens health systems, promotes community and multi-level engagement, and mobilizes partnerships, coordination and resources to advocate for global action. This initiative could accelerate multi-disciplinary research and action in central Africa, a “hotspot” for SBE, but it offers little specific guidance about anthropological research to be conducted. This commentary develops that research agenda. It surveys anthropological, ethnohistorical investigations in the central African forest to elaborate the socio-cultural and historical significance and practices around snakes and snakebites. It draws from south and southeast Asian and Latin American literatures to illustrate anthropological contributions to SBE research. It then outlines a Central African research agenda employing ethnobiological...

Part 1 General Information: Overview. Part 2 Form and Distinguishing Features: External Features Internal Features. Part 3 Biology and Evolution: Ecology Feeding and Food Reproduction Enemies and Defense Mimicry - Imitation Fellowships Biogeography, Origin and Evolution. Part 4 Venoms and Snakebite: Venoms in Biology and Their Value Studies of Coral Snake Venom Chemical and Biological Characteristics of Venom Coral Snake Bite Accidents. Part 5 Identification, Description and Distribution By Countries: Identification Description of Species and Subspecies with Keys to the Subspecies Distribution by Countries. Appendices: Scientific and Common Names of Coral Snakes Summary of the Composition of Coral Snake Venom.

Hump-nosed viper (Hypnale species) bites are common in Sri Lanka and a proportion of these bites lead to coagulation abnormalities and acute kidney injury (AKI). We observed thrombotic microangiopathy (TMA) among some of these patients, but its contribution to severity of AKI and other morbidities remains unknown. Thus, we report a case series of TMA following hump-nosed viper bite addressing the complications and renal out comes in Sri Lanka. This was a prospective observational study carried out at the nephrology unit, Kandy in Sri Lanka from October 2010 to October 2011 and included 11 patients with AKI following hump-nosed viper bites. All eleven cases needed renal replacement therapy (RRT) with intermittent haemodialysis for a period of 1-5 weeks. Of them, 7 patients developed TMA with evidence of microangiopathic haemolytic anaemia (MAHA), thrombocytopenia and severe anaemia needing multiple blood transfusions. They needed longer duration of RRT (range 2-5 weeks); 2 patients d...

The WHO has identified the goal of halving deaths and disability from snakebite envenomation (SBE) by 2030 through a four-pillar program that promotes accessible and affordable treatments, strengthens health systems, promotes community and multi-level engagement, and mobilizes partnerships, coordination and resources to advocate for global action. This initiative could accelerate multidisciplinary research and action in central Africa, a "hotspot" for SBE, but it offers little specific guidance about anthropological research to be conducted. This commentary develops that research agenda. It surveys anthropological, ethnohistorical investigations in the central African forest to elaborate the socio-cultural and historical significance and practices around snakes and snakebites. It draws from south and southeast Asian and Latin American literatures to illustrate anthropological contributions to SBE research. It then outlines a Central African research agenda employing ethnobiological investigation of snake ecologies, participatory evaluations of humans-snake contacts, and interviews and participant-observation of local prevention and treatment practices and knowledge. This research will co-develop policies and practices with forest communities and leaders and regional and national authorities to reduce the burden of SBE.