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1.
Sci Rep ; 14(1): 11157, 2024 06 04.
Article in English | MEDLINE | ID: mdl-38834598

ABSTRACT

Snakebite envenomation is a major public health issue which causes severe morbidity and mortality, affecting millions of people annually. Of a diverse range of clinical manifestations, local and systemic haemorrhage are of particular relevance, as this may result in ischemia, organ failure and even cardiovascular shock. Thus far, in vitro studies have failed to recapitulate the haemorrhagic effects observed in vivo. Here, we present an organ-on-a-chip approach to investigate the effects of four different snake venoms on a perfused microfluidic blood vessel model. We assess the effect of the venoms of four snake species on epithelial barrier function, cell viability, and contraction/delamination. Our findings reveal two different mechanisms by which the microvasculature is being affected, either by disruption of the endothelial cell membrane or by delamination of the endothelial cell monolayer from its matrix. The use of our blood vessel model may shed light on the key mechanisms by which tissue-damaging venoms exert their effects on the capillary vessels, which could be helpful for the development of effective treatments against snakebites.


Subject(s)
Lab-On-A-Chip Devices , Snake Venoms , Animals , Humans , Endothelial Cells/drug effects , Hemorrhage , Cell Survival/drug effects , Snake Bites/drug therapy , Human Umbilical Vein Endothelial Cells/drug effects , Microphysiological Systems
2.
Nat Commun ; 15(1): 4310, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38773068

ABSTRACT

Oligoclonal mixtures of broadly-neutralizing antibodies can neutralize complex compositions of similar and dissimilar antigens, making them versatile tools for the treatment of e.g., infectious diseases and animal envenomations. However, these biotherapeutics are complicated to develop due to their complex nature. In this work, we describe the application of various strategies for the discovery of cross-neutralizing nanobodies against key toxins in coral snake venoms using phage display technology. We prepare two oligoclonal mixtures of nanobodies and demonstrate their ability to neutralize the lethality induced by two North American coral snake venoms in mice, while individual nanobodies fail to do so. We thus show that an oligoclonal mixture of nanobodies can neutralize the lethality of venoms where the clinical syndrome is caused by more than one toxin family in a murine challenge model. The approaches described may find utility for the development of advanced biotherapeutics against snakebite envenomation and other pathologies where multi-epitope targeting is beneficial.


Subject(s)
Antibodies, Neutralizing , Coral Snakes , Single-Domain Antibodies , Animals , Single-Domain Antibodies/immunology , Mice , Antibodies, Neutralizing/immunology , Coral Snakes/immunology , Disease Models, Animal , Antivenins/immunology , Elapid Venoms/immunology , Female , Snake Bites/immunology , Snake Bites/therapy , Epitopes/immunology , Mice, Inbred BALB C , Cell Surface Display Techniques
3.
Toxins (Basel) ; 16(5)2024 May 11.
Article in English | MEDLINE | ID: mdl-38787074

ABSTRACT

Snakebite envenoming and its resulting complications are serious threats to the health of vulnerable people living in rural areas of developing countries. The knowledge of the heterogeneity of symptoms associated with snakebite envenoming and their management strategies is vital to treat such life-threatening complications to save lives. Russell's viper envenomation induces a diverse range of clinical manifestations from commonly recognised haemotoxic and local effects to several rare conditions that are often not reported. The lack of awareness about these unusual manifestations can affect prompt diagnosis, appropriate therapeutic approaches, and positive outcomes for patients. Here, we report pulmonary thromboembolism that developed in three patients following Russell's viper envenomation and demonstrate their common clinical features and diagnostic and therapeutic approaches used. All patients showed clinical signs of local (oedema) and systemic (blood coagulation disturbances) envenomation, which were treated using polyvalent antivenom. They exhibited elevated heart rates, breathlessness, and reduced oxygen saturation, which are non-specific but core parameters in the diagnosis of pulmonary embolism. The recognition of pulmonary embolism was also achieved by an electrocardiogram, which showed sinus tachycardia and computed tomography and echocardiogram scans further confirmed this condition. Anti-coagulant treatment using low-molecular-weight heparin offered clinical benefits in these patients. In summary, this report reinforces the broad spectrum of previously unreported consequences of Russell's viper envenomation. The constant updating of healthcare professionals and the dissemination of major lessons learned in the clinical management of snakebite envenoming through scientific documentation and educational programs are necessary to mitigate the adverse impacts of venomous snakebites in vulnerable communities.


Subject(s)
Antivenins , Daboia , Pulmonary Embolism , Snake Bites , Snake Bites/complications , Snake Bites/drug therapy , Pulmonary Embolism/etiology , Pulmonary Embolism/drug therapy , Humans , Animals , Male , Antivenins/therapeutic use , Viper Venoms/toxicity , Adult , Female , Middle Aged , Anticoagulants/therapeutic use
4.
Toxicon ; 244: 107757, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38740099

ABSTRACT

Naja naja snake bite causes thousands of deaths worldwide in a year. N. naja envenomed victims exhibit both local and systemic reactions that potentially lead to death. In clinical practice, pulmonary complications in N. naja envenomation are commonly encountered. However, the molecular mechanisms underlying N. naja venom-induced lung toxicity remain unknown. Here, we reasoned that N. naja venom-induced lung toxicity is prompted by NLRP3 inflammasome and MAPKs activation in mice. Treatment with dimethyl ester of bilirubin (BD1), significantly inhibited the N. naja venom-induced activation of NLRP3 inflammasome and MAPKs both in vivo and in vitro (p < 0.05). Further, BD1 reduced N. naja venom-induced recruitment of inflammatory cells, and hemorrhage in the lung toxicity examined by histopathology. BD1 also diminished N. naja venom-induced local toxicities in paw edema and myotoxicity in mice. Furthermore, BD1 was able to enhance the survival time against N. naja venom-induced mortality in mice. In conclusion, the present data showed that BD1 alleviated N. naja venom-induced lung toxicity by inhibiting NLRP3 inflammasome and MAPKs activation. Small molecule inhibitors that intervene in venom-induced toxicities may have therapeutic applications complementing anti-snake venom.


Subject(s)
Elapid Venoms , Inflammasomes , NLR Family, Pyrin Domain-Containing 3 Protein , Naja naja , Animals , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/antagonists & inhibitors , Mice , Elapid Venoms/toxicity , Bilirubin , Snake Bites/drug therapy , Lung/drug effects , Lung/pathology , Mitogen-Activated Protein Kinases/metabolism , Male
5.
F1000Res ; 13: 192, 2024.
Article in English | MEDLINE | ID: mdl-38708289

ABSTRACT

On the 26 th January 2023, a free to attend, 'improving in vivo snake venom research: a community discussion' meeting was held virtually. This webinar brought together researchers from around the world to discuss current neutralisation of venom lethality mouse assays that are used globally to assess the efficacy of therapies for snakebite envenoming. The assay's strengths and weaknesses were highlighted, and we discussed what improvements could be made to refine and reduce animal testing, whilst supporting preclinical antivenom and drug discovery for snakebite envenoming. This report summarises the issues highlighted, the discussions held, with additional commentary on key perspectives provided by the authors.


Subject(s)
Antivenins , Snake Bites , Snake Venoms , Antivenins/therapeutic use , Animals , Snake Venoms/antagonists & inhibitors , Mice , Snake Bites/drug therapy , Humans
6.
Toxicon ; 243: 107744, 2024 May 28.
Article in English | MEDLINE | ID: mdl-38701904

ABSTRACT

Snakebite poses a significant health threat in numerous tropical and subtropical nations, with around 5.4 million cases reported annually, which results in 1.8-2.7 million instances of envenomation, underscoring its critical impact on public health. The 'BIG FOUR' group comprises the primary committers responsible for most snake bites in India. Effective management of snakebite victims is essential for prognosis, emphasizing the need for preventive measures to limit snakebite-related deaths. The proposed initiative seeks to develop a transfer learning-based image classification algorithm using DenseNet to identify venomous and non-venomous snakes automatically. The study comprehensively evaluates the image classification results, employing accuracy, F1-score, Recall, and Precision metrics. DenseNet emerges as a potent tool for multiclass snake image classification, achieving a notable accuracy rate of 86%. The proposed algorithm intends to be incorporated into an AI-based snake-trapping device with artificial prey made with tungsten wire and vibration motors to mimic heat and vibration signatures, enhancing its appeal to snakes. The proposed algorithm in this research holds promise as a primary tool for preventing snake bites globally, offering a path toward automated snake capture without human intervention. These findings are significant in preventing snake bites and advancing snakebite mitigation strategies.


Subject(s)
Algorithms , Deep Learning , Snake Bites , Snakes , Animals , Snakes/classification , India , Humans
7.
Res Vet Sci ; 173: 105287, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38718545

ABSTRACT

Envenomation of dogs by the common European adder (Vipera berus) is associated with high morbidity. The cytotoxic venom of Vipera berus contains enzymes with the potential to cause acute kidney injury, among other insults, however robust biomarkers for such effects are lacking. A prospective observational follow-up study of naturally envenomated dogs and controls was conducted to fill knowledge gaps regarding canine Vipera berus envenomation, attempt to identify novel biomarkers of envenomation and related kidney injury, and elucidate potential long-term effects. Blood and urine samples were analyzed with a global metabolomics approach using liquid chromatography-mass spectrometry, uncovering numerous features significantly different between cases and controls. After data processing and feature annotation, eight features in blood and 24 features in urine were investigated in order to elucidate their biological relevance. Several of these are associated with AKI, while some may also originate from disturbed fatty acid ß-oxidation and soft tissue damage. A metabolite found in both blood and a venom reference sample may represent identification of a venom component in case dogs. Our findings suggest that envenomated dogs treated according to current best practice are unlikely to suffer permanent injury.


Subject(s)
Dog Diseases , Metabolome , Snake Bites , Viperidae , Animals , Dogs , Snake Bites/veterinary , Snake Bites/blood , Snake Bites/urine , Dog Diseases/urine , Dog Diseases/blood , Male , Longitudinal Studies , Female , Prospective Studies , Viper Venoms/urine , Biomarkers/urine , Biomarkers/blood , Acute Kidney Injury/veterinary , Acute Kidney Injury/urine , Acute Kidney Injury/blood , Vipera
8.
Int Immunopharmacol ; 134: 112215, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38744173

ABSTRACT

Camelid single-domain antibodies (VHH) represent a promising class of immunobiologicals for therapeutic applications due to their remarkable stability, specificity, and therapeutic potential. To enhance the effectiveness of antivenoms for snakebites, various methods have been explored to address limitations associated with serum therapy, particularly focusing on mitigating local damage and ensuring sustainable production. Our study aimed to characterize the pharmacological profile and neutralization capacity of anti-Phospholipase A2 (PLA2) monomeric VHH (Genbank accessions: KC329718). Using a post-envenoming mouse model, we used intravital microscopy to assess leukocyte influx, measured CK and LDH levels, and conducted a histopathology analysis to evaluate VHH KC329718's ability to neutralize myotoxic activity. Our findings demonstrated that VHH KC329718 exhibited heterogeneous distribution in muscle tissue. Treatment with VHH KC329718 reduced leukocyte influx caused by BthTX-I (a Lys-49 PLA2) by 28 %, as observed through intravital microscopy. When administered at a 1:10 ratio [venom or toxin:VHH (w/w)], VHH KC329718 significantly decreased myotoxicity, resulting in a 35-40 % reduction in CK levels from BthTX-I and BthTX-II (an Asp-49 PLA2) and a 60 % decrease in CK levels from B. jararacussu venom. LDH levels also showed reductions of 60%, 80%, and 60% induced by BthTX-I, BthTX-II, and B. jararacussu venom, respectively. Histological analysis confirmed the neutralization potential, displaying a significant reduction in tissue damage and inflammatory cell count in mice treated with VHH KC329718 post B. jararacussu venom inoculation. This study underscores the potential of monomeric anti-PLA2 VHH in mitigating myotoxic effects, suggesting a promising avenue for the development of new generation antivenoms to address current therapeutic limitations.


Subject(s)
Antivenins , Bothrops , Phospholipases A2 , Single-Domain Antibodies , Snake Bites , Animals , Single-Domain Antibodies/immunology , Snake Bites/drug therapy , Snake Bites/immunology , Antivenins/pharmacology , Antivenins/therapeutic use , Mice , Phospholipases A2/metabolism , Crotalid Venoms/immunology , Crotalid Venoms/toxicity , Male , Disease Models, Animal , Muscle, Skeletal/pathology , Muscle, Skeletal/drug effects , Leukocytes/drug effects , Leukocytes/immunology , Humans , Creatine Kinase/blood
9.
PLoS Negl Trop Dis ; 18(5): e0012161, 2024 May.
Article in English | MEDLINE | ID: mdl-38768190

ABSTRACT

BACKGROUND: Snakebite is a major poverty-related neglected tropical disease. An integrated scientific approach is needed to understand the dynamics of this important health issue. Our objective was to estimate snakebite occurrence in a tropical area by using a blend of ecological modelling and robust statistical analysis. METHODS: The present study used climatic, environmental, and human population density data to determine the area with snakebite occurrence-probability for the first time in Bangladesh. We also analysed a large, 16-year dataset of hospitalized snakebite cases to reveal the epidemiology of snakebite in the south-eastern zone of the country. FINDINGS: Our results show that cobra bite is the most commonly occurring venomous snakebite in humans (around ~12% of the total yearly snakebite records), and men are more frequently bitten than women (2/3 of human victims are men). Most bites occur during the rainy season for cobra and green pit viper, while krait bites are not restricted to any particular season. As snakebite incidents are closely related to climate conditions, we can model snakebite risk using temperature and precipitation variables. Whereas there is a lack of snakebite reports from several parts of the study area in official records, our models predict that the entire study area is favourable for snakebite incidents. Based on the combined evidence we estimate that about 200,000 snakebite events occur every year in the south-eastern part of Bangladesh alone. Considering future global climate change, our model projections show that snakebite incidence in Bangladesh might not significantly decrease in the future (- 2070-); however, the distribution of probabilities might change, with a predicted increase of snakebite incidence in the hilly areas of the country. CONCLUSIONS: Using climatic data to predict snakebite incidence in Bangladesh allowed us to provide estimations of the total annual number of snakebite cases in the study area. As in most countries, the scarcity of accurate epidemiological data in official records might have masked the real magnitude of this problem. Our analysis suggests that the problem of snakebite envenoming in Bangladesh might be worse than currently perceived. A long-term sustainable snakebite program plan should be designed and institutionalized, considering climatic, geographical and human demographic variables, to obtain better data and facilitate the implementation of accurate snakebite management programs for this country.


Subject(s)
Snake Bites , Snake Bites/epidemiology , Humans , Bangladesh/epidemiology , Male , Female , Animals , Adult , Adolescent , Seasons , Young Adult , Middle Aged , Child , Child, Preschool , Incidence
10.
PLoS Negl Trop Dis ; 18(5): e0012152, 2024 May.
Article in English | MEDLINE | ID: mdl-38717980

ABSTRACT

BACKGROUND: Each year, 3,800 cases of snakebite envenomation are reported in Mexico, resulting in 35 fatalities. The only scientifically validated treatment for snakebites in Mexico is the use of antivenoms. Currently, two antivenoms are available in the market, with one in the developmental phase. These antivenoms, produced in horses, consist of F(ab')2 fragments generated using venoms from various species as immunogens. While previous studies primarily focused on neutralizing the venom of the Crotalus species, our study aims to assess the neutralization capacity of different antivenom batches against pit vipers from various genera in Mexico. METHODOLOGY: We conducted various biological and biochemical tests to characterize the venoms. Additionally, we performed neutralization tests using all three antivenoms to evaluate their effectiveness against lethal activity and their ability to neutralize proteolytic and fibrinogenolytic activities. RESULTS: Our results reveal significant differences in protein content and neutralizing capacity among different antivenoms and even between different batches of the same product. Notably, the venom of Crotalus atrox is poorly neutralized by all evaluated batches despite being the primary cause of envenomation in the country's northern region. Furthermore, even at the highest tested concentrations, no antivenom could neutralize the lethality of Metlapilcoatlus nummifer and Porthidium yucatanicum venoms. These findings highlight crucial areas for improving existing antivenoms and developing new products. CONCLUSION: Our research reveals variations in protein content and neutralizing potency among antivenoms, emphasizing the need for consistency in venom characteristics as immunogens. While Birmex neutralizes more LD50 per vial, Antivipmyn excels in specific neutralization. The inability of antivenoms to neutralize certain venoms, especially M. nummifer and P. yucatanicum, highlights crucial improvement opportunities, given the medical significance of these species.


Subject(s)
Antivenins , Neutralization Tests , Antivenins/pharmacology , Antivenins/immunology , Animals , Mexico , Snake Bites/drug therapy , Snake Bites/immunology , Viperidae , Crotalus , Crotalid Venoms/immunology
11.
J Glob Health ; 14: 04096, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38726547

ABSTRACT

Background: This study aimed to investigate attitudes towards health education on snakebites and to identify the influencing factors among Chinese residents. Additionally, we proposed effective health education strategies for snakebite management. Methods: Between May 2022 and February 2023, we conducted a nationwide cross-sectional questionnaire survey using a multistage sampling method with supplementary snowball sampling. We used descriptive analysis, χ2 tests, and univariable and multivariable binary logistic regression models to analyse the data. Results: We included 56 669 respondents in the analysis. The average score for snakebite knowledge was 12.13 ± 5.26 points, with a maximum score of 28. Among the respondents, 72.66 and 63.03% of the residents believed that it was necessary to disseminate knowledge about snakebites and expressed a willingness to receive snakebite training, respectively. Respondents from the northeast region, respondents with a higher education level, and respondents with higher scores for snakebite knowledge, health knowledge, health skills, and social-psychological adjustment skills exhibited more positive attitudes towards snakebite knowledge dissemination and training. Conversely, respondents from eastern or southern China, respondents older than 60, and respondents who lived in rudimentary housing conditions showed a lower perception of the need for snakebite knowledge dissemination and were less willing to participate in snakebite knowledge and skill training. Conclusions: Generally, Chinese residents have positive attitudes towards snakebite knowledge dissemination and training. However, the public lacks sufficient knowledge about snakebites. Therefore, we should pay close attention to areas south of the Yangtze River to strengthen snakebite health education using engaging formats that align with residents' interests, such as short videos or television programmes, in an attempt to and ultimately improve health literacy and prevention awareness.


Subject(s)
Health Education , Health Knowledge, Attitudes, Practice , Snake Bites , Humans , Snake Bites/psychology , Snake Bites/prevention & control , Cross-Sectional Studies , Male , Female , China/epidemiology , Adult , Middle Aged , Surveys and Questionnaires , Young Adult , Aged , Adolescent
12.
BMJ Case Rep ; 17(5)2024 May 23.
Article in English | MEDLINE | ID: mdl-38782420

ABSTRACT

Certain snake envenomation patients with consumptive coagulopathy, termed venom-induced consumption coagulopathy, develop thrombotic microangiopathy (TMA). Due to predominant renal involvement, TMA is said to resemble haemolytic uraemic syndrome and is treated with haemodialysis. We present a case of a young male who presented to the emergency department after being bitten by a white-lipped pit viper (Trimeresurus albolabris). He developed heart failure in addition to acute kidney injury secondary to TMA. He was treated with 30 vials of anti-snake venom according to national guidelines and underwent haemodialysis. Despite haemodialysis, the patient's ventilatory parameters continued to worsen, necessitating invasive mechanical ventilation. Thus, he was initiated on plasma exchange therapy, to which the patient responded well. TMA has not been reported in Trimeresurus envenomations yet, to the best of our knowledge. Additionally, plasma exchange therapy can be considered an adjunctive therapy for snakebite patients who develop TMA.


Subject(s)
Plasma Exchange , Snake Bites , Thrombotic Microangiopathies , Humans , Snake Bites/complications , Snake Bites/therapy , Thrombotic Microangiopathies/etiology , Thrombotic Microangiopathies/therapy , Male , Animals , Plasma Exchange/methods , Acute Kidney Injury/etiology , Acute Kidney Injury/therapy , Trimeresurus , Antivenins/therapeutic use , Adult , Renal Dialysis , Heart Failure/etiology , Heart Failure/therapy
13.
BMJ Case Rep ; 17(5)2024 May 22.
Article in English | MEDLINE | ID: mdl-38782437

ABSTRACT

In cases of severe envenomation due to snakebites, patients require antivenom, intensive care management, including respiratory support, haemodynamic monitoring and renal replacement therapy. Early recognition and treatment of complications such as acute kidney injury, rhabdomyolysis and coagulopathy are important to improve outcomes.Tele-ICU models can play a critical role in providing access to critical care expertise and nuanced support to remote healthcare facilities that may not have the necessary resources or expertise to manage complex cases of envenomation. With the help of telemedicine technology, remote intensivists can provide timely guidance on diagnosis and ongoing management, improving the quality of care and outcomes for patients. We discuss two patients in resource-constrained regions of India with severe envenomation who were managed with tele-ICU support.


Subject(s)
Antivenins , Snake Bites , Telemedicine , Humans , India , Snake Bites/therapy , Snake Bites/complications , Antivenins/therapeutic use , Antivenins/administration & dosage , Male , Critical Care/methods , Intensive Care Units , Adult , Acute Kidney Injury/therapy , Acute Kidney Injury/etiology , Animals , Female
14.
PLoS Negl Trop Dis ; 18(5): e0012187, 2024 May.
Article in English | MEDLINE | ID: mdl-38809847

ABSTRACT

BACKGROUND: Snakebite envenomation inflicts a high burden of mortality and morbidity in sub-Saharan Africa. Antivenoms are the mainstay in the therapy of envenomation, and there is an urgent need to develop antivenoms of broad neutralizing efficacy for this region. The venoms used as immunogens to manufacture snake antivenoms are normally selected considering their medical importance and availability. Additionally, their ability to induce antibody responses with high neutralizing capability should be considered, an issue that involves the immunization scheme and the animal species being immunized. METHODOLOGY/PRINCIPAL FINDINGS: Using the lethality neutralization assay in mice, we compared the intrageneric neutralization scope of antisera generated by immunization of horses with monospecific, bispecific/monogeneric, and polyspecific/monogeneric immunogens formulated with venoms of Bitis spp., Echis spp., Dendroaspis spp., spitting Naja spp. or non-spitting Naja spp. It was found that the antisera raised by all the immunogens were able to neutralize the homologous venoms and, with a single exception, the heterologous congeneric venoms (considering spitting and non-spitting Naja separately). In general, the polyspecific antisera of Bitis spp, Echis spp, and Dendroaspis spp gave the best neutralization profile against venoms of these genera. For spitting Naja venoms, there were no significant differences in the neutralizing ability between monospecific, bispecific and polyspecific antisera. A similar result was obtained in the case of non-spitting Naja venoms, except that polyspecific antiserum was more effective against the venoms of N. melanoleuca and N. nivea as compared to the monospecific antiserum. CONCLUSIONS/SIGNIFICANCE: The use of polyspecific immunogens is the best alternative to produce monogeneric antivenoms with wide neutralizing coverage against venoms of sub-Saharan African snakes of the Bitis, Echis, Naja (non-spitting) and Dendroaspis genera. On the other hand, a monospecific immunogen composed of venom of Naja nigricollis is suitable to produce a monogeneric antivenom with wide neutralizing coverage against venoms of spitting Naja spp. These findings can be used in the design of antivenoms of wide neutralizing scope for sub-Saharan Africa.


Subject(s)
Antivenins , Neutralization Tests , Animals , Horses/immunology , Antivenins/immunology , Antivenins/administration & dosage , Mice , Africa South of the Sahara , Antibodies, Neutralizing/immunology , Antibodies, Neutralizing/blood , Snake Venoms/immunology , Immune Sera/immunology , Elapid Venoms/immunology , Snake Bites/immunology
15.
BMJ Case Rep ; 17(5)2024 May 08.
Article in English | MEDLINE | ID: mdl-38719248

ABSTRACT

Snakebite envenomation remains a neglected tropical public health issue claiming thousands of lives every year. It is a common medical emergency and a threat to the impoverished populations of low-income and middle-income countries including India. A combination of ischaemic stroke and deep vein thrombosis is a devastating duo complication of snake bite, with no literature report to date. Here, the authors report an unusual case of a young woman developing ischaemic stroke and deep vein thrombosis following snakebite even after the use of antivenom. MRI brain showed right thalamic infarct with haemorrhagic transformation and, ultrasound Doppler revealed right lower limb deep vein thrombosis. The pathophysiology of deep vein thrombosis and ischaemic stroke is complex. It is believed that the activation of the coagulation cascade, complement system together with endothelial injury and immune activation leads to inflammation, thrombosis and occlusion of smaller and even larger vessels.


Subject(s)
Ischemic Stroke , Snake Bites , Venous Thrombosis , Humans , Snake Bites/complications , Female , Venous Thrombosis/etiology , Venous Thrombosis/diagnostic imaging , Ischemic Stroke/etiology , Adult , Antivenins/therapeutic use , Magnetic Resonance Imaging , Animals
16.
J Emerg Med ; 66(5): e601-e605, 2024 May.
Article in English | MEDLINE | ID: mdl-38702243

ABSTRACT

BACKGROUND: A minority of snake envenomations in the United States involve non-native snakes. In this report, we describe what we believe is the first documented human envenoming from an emerald horned pitviper, Ophryacus smaragdinus. CASE REPORT: A previously healthy 36-year-old woman was bitten on her left index finger by a captive emerald horned pitviper she was medicating at work. Swelling to the entire hand was present on emergency department arrival. She had no systemic symptoms and her initial laboratory studies were unremarkable. The affected limb was elevated. We administered five vials of Antivipmyn TRIⓇ (Bioclon), which specifically lists Ophryacus among the envenomations for which it is indicated. She developed pruritus and was treated with IV diphenhydramine and famotidine. Her swelling improved, but her repeat laboratory studies were notable for a platelet count of 102 K/µL and a fibrinogen level of 116 mg/dL. She declined additional antivenom because of the previous allergic reaction. She was admitted for further monitoring and pain control. Subsequent laboratory tests were better, but a small hemorrhagic bleb developed at the bite site. She was discharged the next day and followed up as an outpatient. Her swelling had resolved, her bleb had healed, and her laboratory studies continued to improve. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians may be required to treat bites from non-native snakes. Many of these bites will warrant treatment with non-U.S. Food and Drug Administration-approved antivenoms. Consultation with a regional poison center or medical toxicologist may be necessary to procure the proper antivenom.


Subject(s)
Antivenins , Snake Bites , Female , Humans , Adult , Snake Bites/complications , Antivenins/therapeutic use , Animals , Crotalinae , Crotalid Venoms
17.
Sci Rep ; 14(1): 10230, 2024 05 03.
Article in English | MEDLINE | ID: mdl-38702318

ABSTRACT

Snakebites affect millions of people worldwide. The majority of research and management about snakebites focus on venom and antivenom, with less attention given to snake ecology. The fundamental factor in snakebites is the snakes' defensive biting behavior. Herein we examine the effects of environmental variables (temperature, time of day, and human stimulus) and biological variables (sex and body size) on the biting behavior of a medically significant pit viper species in Brazil, Bothrops jararaca (Viperidae), and associate it with the epidemiology of snakebites. Through experimental simulations of encounters between humans and snakes, we obtained behavioral models applicable to epidemiological situations in the State of São Paulo, Brazil. We found a significant overlap between behavioral, morphological, environmental, and epidemiological data. Variables that increase snakebites in epidemiological data also enhance the tendency of snakes to bite defensively, resulting in snakebites. We propose that snakebite incidents are influenced by environmental and morphological factors, affecting the behavior of snakes and the proportion of incidents. Thus, investigating behavior of snakes related to snakebite incidents is a valuable tool for a better understanding of the epidemiology of these events, helping the prediction and, thus, prevention of snakebites.


Subject(s)
Behavior, Animal , Bothrops , Snake Bites , Snake Bites/epidemiology , Snake Bites/psychology , Animals , Humans , Male , Female , Brazil/epidemiology , Venomous Snakes
18.
Toxicon ; 244: 107775, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38782188

ABSTRACT

Patients occasionally present with reports of ocular exposure to fluids from rattlesnakes, claiming or suspecting the substance to be venom. This study set out to evaluate and characterize reported cases of suspected venom-induced ophthalmia in humans. A retrospective review of rattlesnake exposures reported to the Arizona Poison and Drug Information Center over a 24-year period was conducted for ocular exposures. Recorded information included patient demographics, clinical course, laboratory results, and treatments. Documentation regarding interactions between patients and snakes was reviewed by Arizona Poison and Drug Information Center herpetologists to evaluate what substance was expelled from the snake resulting in ocular exposure. Our review of rattlesnake encounters found a total of 26 ocular exposure cases. Patient demographics were largely intentional interactions and involved the male sex. Symptoms ranged from asymptomatic to minor effects with 46.2% managed from home and treated with fluid irrigation. A review of cases by herpetologists concluded the exposure patients commonly experienced was to snake musk. Kinematics of venom expulsion by rattlesnakes conclude the venom gland must be compressed, fangs erected to ≥60o, and fang sheath compressed against the roof of the mouth for venom expulsion. Evidence suggests the chance of venom "spitting" by rattlesnakes is close to zero. Rattlesnakes are documented to forcefully expel airborne malodorous "musk" defensively. An important distinction to remember is musk has a foul odor and is usually colorless, while venom is comparatively odorless and yellow. Rattlesnake venom-induced ophthalmia is a rare event as venom expulsion requires the kinematics of feeding or defensive bites. If the rattlesnake is not in the process of biting or otherwise contacting some other object with its mouth, it is more biologically plausible patients are being exposed to snake musk as a deterrent. Whether it's venom or musk, topical exposure to the eyes should prompt immediate irrigation.


Subject(s)
Crotalid Venoms , Crotalus , Snake Bites , Animals , Arizona , Humans , Male , Retrospective Studies , Female , Crotalid Venoms/toxicity , Adult , Middle Aged , Adolescent , Aged , Child , Eye/drug effects , Young Adult , Poison Control Centers
19.
Toxicon ; 244: 107776, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38795850

ABSTRACT

The impact of Covid-19 on envenomations by venomous animals in countries heavily affected by both conditions has not been quantified yet. Brazil shows high incidence of envenomations by scorpions, spiders and snakes and was heavily affected by waves of Covid-19. To determine how the pandemic impacted the epidemiology of envenomations by those three groups of venomous animals, we used online databases from two surveillance sources on number of cases and mortality. During the years before and during the pandemic, scorpion stings typically occurred in adults of both sexes in urban zones in the Southeast and Northeast regions. Spider bites occurred mainly in the South region, in adults of both sexes in urban zone. Snakebites affected mainly rural adult men in the Amazon. Between 2007 and 2021, overall incidence of cases by scorpions, spiders and snakes decreased after the beginning of the pandemic, snakebites did not show changes after the pandemic started in Brazil, but cases by scorpions and spiders decreased. No changes in the incidence of deaths were observed. On national level, Covid-19 affected some demographic, clinical and epidemiological aspects in cases by scorpions, spiders and snakes.


Subject(s)
COVID-19 , Scorpion Stings , Snake Bites , Brazil/epidemiology , COVID-19/epidemiology , Humans , Snake Bites/epidemiology , Animals , Male , Female , Adult , Incidence , Scorpion Stings/epidemiology , Spider Bites/epidemiology , Middle Aged , Adolescent , Young Adult , Child , SARS-CoV-2 , Scorpions , Snakes , Pandemics , Aged
20.
Toxicon ; 244: 107751, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38723869

ABSTRACT

This report details a documented case of fatal King cobra (Ophiophagus hannah) envenomation in the Philippines. A 46-year-old woman from a mountainous town in Leyte was bitten on her left thigh by a snake. Despite receiving prompt medical attention, including administration of fluids and oxygen, she went into arrest and succumbed within 2.5 hours of the bite. Inadequate pre-hospital care, including endotracheal intubation and assisted ventilation, highlights a notable gap in emergency medical services. Photographic evidence, verified by a herpetologist, confirmed the involvement of a King cobra, with venom presenting with a swift and lethal systemic effect that led to the patient's demise, despite minimal local manifestations. This incident accentuates the urgent need for accessible, effective antivenom and improved snakebite management protocols in the Philippines. It also calls for heightened awareness and preparedness among pre-hospital healthcare providers and the public, alongside advocating for more research into snakebite envenomation.


Subject(s)
Elapid Venoms , Elapidae , Snake Bites , Animals , Female , Middle Aged , Humans , Philippines , Fatal Outcome , Antivenins/therapeutic use
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