Defining the role of post-synaptic α-neurotoxins in paralysis due to snake envenoming in humans.

Snake venom α-neurotoxins potently inhibit rodent nicotinic acetylcholine receptors (nAChRs), but their activity on human receptors and their role in human paralysis from snakebite remain unclear. We demonstrate that two short-chain α-neurotoxins (SαNTx) functionally inhibit human muscle-type nAChR, but are markedly more reversible than against rat receptors. In contrast, two long-chain α-neurotoxins (LαNTx) show no species differences in potency or reversibility. Mutant studies identified two key residues accounting for this. Proteomic and clinical data suggest that paralysis in human snakebites is not associated with SαNTx, but with LαNTx, such as in cobras. Neuromuscular blockade produced by both subclasses of α-neurotoxins was reversed by antivenom in rat nerve-muscle preparations, supporting its effectiveness in human post-synaptic paralysis.

Venomous Snake Bite in India - Why do 50,000 Indians Die Every Year?

Snakebite is an occupational hazard causing considerable morbidity and mortality worldwide, particularly so in tropical countries like India. An estimated 50,000 Indians die due to venomous snakebite every year, seventy percent of whom are males between the ages of 20 to 50 years. Along with the associated morbidity and mortality, snakebite leads to a significant financial burden on the victim, both by way of hospital bills and labour hours lost. Snakebite is also a cause for considerable psychological stress among survivors. Most snakebites are eminently treatable and curable. Given a concerted thrust from all concerned , this menace could surely be curtailed considerably over the next few years.

Histopatholological Findings in a Fatal Case of Rinkhals Envenomation: A New Forensic Pathology Finding?

Although cobra envenomation continues to pose a threat to life and therefore constitutes a major cause of death in Africa, India, and Sri Lanka, the forensic pathology reports are not always histologically well documented or illustrated. The reports in the literature, although providing graphic evidence of the macroscopic appearances of the bite and its ensuing tissue necrosis, should the victim survive, often do not illustrate the histopathological findings to a sufficient degree. We present an unusual case of fatal envenomation by a rinkhals (Hemachatus haemachatus) in which the victim had been bitten a second time after a previous rinkhals' bite. Two issues therefore arose: (a) whether the histopathological findings in the spleen were an acute reaction to the snake bite or were due to immunostimulation as a consequence of the previously inflicted bite, and (b) the previously undocumented finding of extravasation of erythrocytes into the surrounding Virchow-Robin spaces in the brain, a finding usually associated with blunt head trauma and therefore interpreted as a cortical contusion hemorrhage by forensic pathologists.

Severe Snakebite Envenoming in Intensive Care.

Snakebites by exotic venomous snakes can cause serious or even life-threatening envenoming. In Europe and North America most victims are breeders, with a few snakebites from wild native American rattlesnakes. The envenomed victims may present in organ and/or system failure with muscle paralysis, respiratory failure, circulatory instability, acute kidney injury, severe coagulation disorder, and local disability - compartment syndrome and necrosis. Best managed by close collaboration between clinical toxicology and intensive care, most severe envenomings are managed primarily by intensive care physicians. Due to the low incidence of severe envenoming, the clinical course and correct management of these cases are not intrinsically familiar to most physicians. This review article summarizes the clinical syndromes caused by severe envenoming and the therapeutic options available in the intensive care setting.

Snake antivenom for snake venom induced consumption coagulopathy.

BACKGROUND: Snake venom induced consumption coagulopathy is a major systemic effect of envenoming. Observational studies suggest that antivenom improves outcomes for venom induced consumption coagulopathy in some snakebites and not others. However, the effectiveness of snake antivenom in all cases of venom induced consumption coagulopathy is controversial. OBJECTIVES: To assess the effect of snake antivenom as a treatment for venom induced consumption coagulopathy in people with snake bite. SEARCH METHODS: The search was done on 30 January 2015. We searched the Cochrane Injuries Group's Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), Ovid MEDLINE(R), Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily and Ovid OLDMEDLINE(R), Embase Classic+Embase (OvidSP), three other sources, clinical trials registers, and we also screened reference lists. SELECTION CRITERIA: All completed, published or unpublished, randomised, controlled trials with a placebo or no treatment arm, where snake antivenom was administered for venom induced consumption coagulopathy in humans with snake bites. DATA COLLECTION AND ANALYSIS: Two authors reviewed the identified trials and independently applied the selection criteria. MAIN RESULTS: No studies met the inclusion criteria for this review. AUTHORS' CONCLUSIONS: Randomised placebo-controlled trials are required to investigate the effectiveness of snake antivenom for clinically relevant outcomes in patients with venom induced consumption coagulopathy resulting from snake bite. Although ethically difficult, the routine administration of a treatment that has a significant risk of anaphylaxis cannot continue without strong evidence of benefit.

[Exposure to occupational biological risks: experience of a toxicology information center]. / Exposición a agentes de riesgo biológico en trabajadores chilenos: Reporte del Centro de Información Toxicológica de la Pontificia Universidad Católica de Chile (CITUC).

BACKGROUND: Exposure to Biological Agents during work is an emergent type of occupational risk. AIM: To characterize occupational biological risk exposure among Chilean workers which have been registered by the Toxicology Information Center, between January 2006 and December 2009. MATERIAL AND METHODS: All incoming calls reporting exposure to biological agents during the studied period were analyzed. The information obtained from the caller was registered using the Communication Record Instrument of the WHO International Programme on Chemical Safety (IPCS INTOX). RESULTS: In the studied period, 77 calls were received. The mean age of exposed patients was 35 ± 15 years and 57% of them were females. The most common involved agents were vaccines for veterinary use (42%) followed by Loxosceles laeta bites in 16%. The main routes of exposure were injections, cuts and needle stick injuries in 39% and stings and bites in 38%. The highest exposure rates were observed in Southern Chile due to self-inoculation of veterinary vaccines used in the salmon industry (22.7/100.000 actual workers). Fifty-eight percent of calls were from health care workers, and 51% of them were from health care facilities. Sixty percent of exposures occurred during summer and spring. There was a fourfold higher risk of calls involving women exposed to bites or stings (odds ratio (OR) 4.5 (CI95 1.5-13.9, p < 0.01). Men had a fourfold higher risk of being exposed to vaccines or medications for veterinary use (OR 4.2, CI95 1.4-12.6 p < 0.01). CONCLUSIONS: Most calls involving an exposure to a biological agent were caused by self-inoculation of veterinary medications.

[Adder bites in Turku region in 2000 to 2010]. / Kyynpuremat Turun seudulla vuosina 2000-2010.

Adder bites cause dozens of hospital visits and complications in Finland each year Some of the patients also suffer from troublesome late symptoms. We established the number of adder bites, use of antivenin, and degree of severity of the bites in child and adult patients treated at TYKS in 2000 to 2010. Antivenin was given to 9.6% of the bitten adults and 17.3% of the children. The number of adder bites was highest in July. Accidental stepping on an adder or hitting an adder-inhabited tussock with the berry picker's hand were the most common cases. Severe cases were rare.

Bitten by the "flying" tree snake, Chrysopelea paradisi.

BACKGROUND: The paradise tree snake, Chrysopelea paradisi, is a rear-fanged colubrid. Like other members of the genus Chrysopelea, it is able to glide through the air, and thus, is commonly known as a "flying snake." There are few documented effects of its bite on humans. CASE REPORT: A 16-year-old military college student presented to the Emergency Department (ED) of an urban teaching hospital 2 h after being bitten by C. paradisi. There were multiple bite marks and the patient reported moderate pain on the left index finger. There was no evidence of significant local or systemic envenomation. A transient prolonged coagulation profile and raised creatine kinase level were noted. CONCLUSION: The full effects of a bite from C. paradisi remain uncharacterized. This case featured only mild local effect. After the administration of first aid, non-sedating analgesia, anti-tetanus toxoid injection, and broad-spectrum antibiotic coverage, a short stay in the ED observation ward with regular monitoring of vital signs and serial wound inspection are recommended. More effort is required to increase awareness of the prevention and management of snakebite with equal emphasis on conservation of wildlife and their natural habitat.

[Report of a case of poisoning by double snake bite with neurotrope venom at the National Donka Hospital, Conakry (Guinea)]. / À propos d'un cas d'envenimation par double morsure d'un serpent à venin neurotrope à l'hôpital national Donka, Conakry (Guinée).

Poisoning by snake bites remains an important cause of death in developing countries and in Africa in particular. Positive diagnosis is mostly easy because of the interrogation of the family and the local reactions that occur in the bite area. However, it is easy to know the type of the snake because the description by the victim is often unclear. We report a case of poisoning due to double bite by an unidentified snake that led to a clinical picture dominated by neurological and respiratory signs, suggestive of a neurotoxin poisoning in a young man living in rural area. Despite the delay in the management due to the ritual traditional treatment, the symptoms improved after the administration of polyvalent anti-venom. This observation raises the delicate problem of identification of snakes from the clinical symptomatology observed, considering their variety

MicroRNAs in toxic acute kidney injury: Systematic scoping review of the current status.

Acute kidney injury induced by nephrotoxic agents is common, increasing in incidence and associated with considerable morbidity and mortality in developing countries. MicroRNAs are stable biomarkers that can be detected in extracellular fluids. This systematic scoping review aims to describe published research on urinary and circulating microRNAs in toxic acute kidney injury in both animal and human studies. We conducted a literature search, using EMBASE and Medline, for articles on urinary and circulating microRNA in nephrotoxic injuries to February 2020. A total of 21 publications studied acute kidney injury from 12 different toxic agents. Cisplatin was the most common nephrotoxic agent (n = 10), followed by antibiotics (n = 4). There were no randomized controlled trials. An increase in urinary miR-218 predicted acute kidney injury in six different studies, suggesting it is a promising biomarker for nephrotoxin-induced acute kidney injury. There were many factors that prevented a more comprehensive synthesis of microRNA performance including highly variable models, no consistent protocols for RNA isolation, cDNA synthesis and PCR amplification, and variability in normalization methods using reference controls. In conclusion, while microRNAs are promising biomarkers to study nephrotoxic acute kidney injury, the replication of most positive findings is not assessable due to deficient reporting of negative outcomes. A very narrow range of poisons have been studied, and more human data are required. In particular, further studies are needed on the most important causes of nephrotoxic injury, such as pesticides, chemicals, snake envenoming, and medicines other than aminoglycosides and cisplatin.

Ophidism by the green palmsnake.

The author describes his experience following 2 bites to his hand by the same green palmsnake (Philodryas viridissimus) on the same day, and reviews the literature on bites from rear-fanged species of the genus Philodryas. Though this genus has long been thought to include the most venomous colubrid snakes in the Americas, the author's bites were relatively asymptomatic. Fatalities caused by Philodryas seem to be lacking in the primary literature, but mild to moderate symptoms do result from envenomations by at least 2 species. Medical researchers are urged to obtain accurate species identifications and to carefully report symptoms and fatalities from bites of colubrid snakes.

Snakebite during pregnancy: a literature review.

OBJECTIVE: To review reported bites by venomous snakes in pregnant women. METHODS: This is a review of Medline/PubMed articles on venomous snakebites occurring during pregnancy reported in the English literature from 1966 to May 2009. RESULTS: Two hundred thirteen venomous snakebites were reported in pregnant women. The overall case-fatality rate in the pregnant females was approximately 4%, and the fetal loss rate was approximately 20%. CONCLUSIONS: Although rare, venomous bites and stings during pregnancy may have a significant adverse effect on the fetus as well as the mother.

Is the Puerto Rican racer, Alsophis portoricensis, really harmless? A case report series.

Puerto Rico (PR) is home to 10 indigenous species of snake. Alsophis portorricensis has traditionally been considered harmless. In 1961, Hageman classified A portorricensis as somewhere between "venomous" and "nonvenomous." In 1966, Heatwole and Banuchi reported the only case found in the literature of a "venomous" bite from Alsophis portorricensis. Only 6 cases of snakebite were reported to the PR Department of Health from 1998 to 2007; ecchymosis, swelling, and abnormal vital signs were noted in all of the cases. In 5 of these 6 cases, the captured snake was, in fact, identified as Alsophis portorricensis of the Colubridae family; in the remaining case, the description strongly suggests that it was the same species as the others. All bites were inflicted on fingers, which were presented for evaluation from 2 to 24 hours after the event. All documented cases report that the bite lasted from 1 to 4 minutes. All of the victims presented with localized pain and ecchymosis. Localized edema extended from the hand to the elbow in 4 cases, and up to the shoulder in 2 cases. All patients were treated symptomatically, observed at the Emergency Department (ED), and discharged home within 24 hours after the ED evaluation. All patients reported the resolution of symptoms within 1 week. Traditionally, PR has not been associated with any dangerous species of snake. These cases show that the second most abundant snake on the island can inflict a venomous bite, with local and systemic symptoms that warrant adequate preparation by the medical community.

A new case of envenomation by neotropical opisthoglyphous snake Philodryas olfersii (Lichtenstein, 1823) in Recife, State of Pernambuco, Brazil.

Human envenomation by the snakes Colubridae and Dipsadidae are reported in Brazil, and envenomation by the Opisthoglyphous snake Philodryas olfersii could be dangerous. Here, we present the second record of an envenomation by Philodryas olfersii in Pernambuco, northeast Brazil. The male victim presented with mild erythema pain, paraesthesia, local numbness, and swollen lymph nodes. The symptoms were similar to those of a pit viper bite, and disappeared completely after 15 days.

Pets in peril: The relative susceptibility of cats and dogs to procoagulant snake venoms.

Snakebite is a common occurrence for pet cats and dogs worldwide and can be fatal. In Australia the eastern brown snake (Pseudonaja textilis) is responsible for an estimated 76% of reported snakebite cases to domestic pets nationally each year, with the primary pathology being venom-induced consumptive coagulopathy. While only 31% of dogs survive P. textilis bites without antivenom, cats are twice as likely to survive bites (66%). Even with antivenom treatment, cats have a significantly higher survival rate. The reason behind this disparity is unclear. Using a coagulation analyser (Stago STA R Max), we tested the relative procoagulant effects of P. textilis venom-as well as 10 additional procoagulant venoms found around the world-on cat and dog plasma in vitro, as well as on human plasma for comparison. All venoms acted faster upon dog plasma than cat or human, indicating that dogs would likely enter coagulopathic states sooner, and are thus more vulnerable to procoagulant snake venoms. The spontaneous clotting time (recalcified plasma with no venom added) was also substantially faster in dogs than in cats, suggesting that the naturally faster clotting blood of dogs predisposes them to being more vulnerable to procoagulant snake venoms. This is consistent with clinical records showing more rapid onset of symptoms and lethal effects in dogs than cats. Several behavioural differences between cats and dogs are also highly likely to disproportionately negatively affect prognosis in dogs. Thus, compared to cats, dogs require earlier snakebite first-aid and antivenom to prevent the onset of lethal venom effects.

Venomous snakes elicit stronger fear than nonvenomous ones: Psychophysiological response to snake images.

Snakes have been important ambush predators of both primates and human hunter-gatherers throughout their co-evolutionary history. Viperid snakes in particular are responsible for most fatal venomous snakebites worldwide and thus represent a strong selective pressure. They elicit intense fear in humans and are easily recognizable thanks to their distinctive morphotype. In this study, we measured skin resistance (SR) and heart rate (HR) in human subjects exposed to snake pictures eliciting either high fear (10 venomous viperid species) or disgust (10 nonvenomous fossorial species). Venomous snakes subjectively evaluated as frightening trigger a stronger physiological response (higher SR amplitude) than repulsive non-venomous snakes. However, stimuli presented in a block (more intense stimulation) do not trigger a stronger emotional response compared to sequentially presented stimuli (less intense stimulation). There are significant interindividual differences as subjects with high fear of snakes confronted with images of viperid snakes show stronger, longer-lasting, and more frequent changes in SR and higher HR compared to low-fear subjects. Thus, we show that humans demonstrate a remarkable ability to discriminate between dangerous viperids and harmless fossorial snakes, which is also reflected in distinct autonomous body responses.

[The death of Cleopatra]. / Mort de Cléopâtre.

The image of a queen bitten by a snake is controversial and the facts, such as the swiftness of her death and her servants, and scientific experiments are in favour of a deadly poisoning. The author reminds that in the ancient texts the snake had sacred virtues and it was a symbolic image to embellish the suicide of the one who was sentenced to death by the Romans. Octaves set up the myth of a fatal bite which became an iconographic image for the cinema.