RESUMO
Snakebite envenomings kill ~100 000 victims each year and leave many more with permanent sequelae. Antivenoms have been available for more than 125 years but are in need of innovation. A new study by Khalek et al. highlights broadly neutralizing human monoclonal antibodies (mAbs) that might be used to develop recombinant antivenoms with superior therapeutic benefits.
Assuntos
Antivenenos , Mordeduras de Serpentes , Humanos , Animais , Antivenenos/uso terapêutico , Mordeduras de Serpentes/tratamento farmacológico , Anticorpos Monoclonais/uso terapêutico , SerpentesRESUMO
Snakebite envenoming is a neglected tropical disease that causes substantial mortality and morbidity globally. The venom of African spitting cobras often causes permanent injury via tissue-destructive dermonecrosis at the bite site, which is ineffectively treated by current antivenoms. To address this therapeutic gap, we identified the etiological venom toxins in Naja nigricollis venom responsible for causing local dermonecrosis. While cytotoxic three-finger toxins were primarily responsible for causing spitting cobra cytotoxicity in cultured keratinocytes, their potentiation by phospholipases A2 toxins was essential to cause dermonecrosis in vivo. This evidence of probable toxin synergism suggests that a single toxin-family inhibiting drug could prevent local envenoming. We show that local injection with the repurposed phospholipase A2-inhibiting drug varespladib significantly prevents local tissue damage caused by several spitting cobra venoms in murine models of envenoming. Our findings therefore provide a therapeutic strategy that may effectively prevent life-changing morbidity caused by snakebite in rural Africa.
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Acetatos , Venenos Elapídicos , Indóis , Cetoácidos , Necrose , Mordeduras de Serpentes , Animais , Mordeduras de Serpentes/tratamento farmacológico , Camundongos , Humanos , Acrilamidas/farmacologia , Fosfolipases A2/metabolismo , Naja , Elapidae , Queratinócitos/efeitos dos fármacos , Pele/efeitos dos fármacos , Pele/patologia , Reposicionamento de MedicamentosRESUMO
BACKGROUND: Snake venoms can exhibit remarkable inter- and intraspecific variation. While diverse ecological and environmental factors are theorised to explain this variation, only a handful of studies have attempted to unravel their precise roles. This knowledge gap not only impedes our understanding of venom evolution but may also have dire consequences on snakebite treatment. To address this shortcoming, we investigated the evolutionary ecology of venoms of Russell's viper (Daboia russelii) and spectacled cobra (Naja naja), India's two clinically most important snakes responsible for an alarming number of human deaths and disabilities. METHODOLOGY: Several individuals (n = 226) of D. russelii and N. naja belonging to multiple clutches (n = 9) and their mothers were maintained in captivity to source ontogenetic stage-specific venoms. Using various in vitro and in vivo assays, we assessed the significance of prey, ontogeny and sex in driving venom composition, function, and potency. RESULTS: Considerable ontogenetic shifts in venom profiles were observed in D. russelii, with the venoms of newborns being many times as potent as juveniles and adults against mammalian (2.3-2.5 ×) and reptilian (2-10 ×) prey. This is the first documentation of the ontogenetic shift in viperine snakes. In stark contrast, N. naja, which shares a biogeographic distribution similar to D. russelii, deployed identical biochemical cocktails across development. Furthermore, the binding kinetics of cobra venom toxins against synthetic target receptors from various prey and predators shed light on the evolutionary arms race. CONCLUSIONS: Our findings, therefore, provide fascinating insights into the roles of ecology and life history traits in shaping snake venoms.
Assuntos
Evolução Biológica , Animais , Índia , Feminino , Masculino , Daboia , Naja naja , Mordeduras de Serpentes , Venenos Elapídicos/química , Venenos de Víboras/químicaRESUMO
Snake venom variations are a crucial factor to understand the consequences of snakebite envenoming worldwide, and therefore it is important to know about toxin composition alterations between taxa. Palearctic vipers of the genera Vipera, Montivipera, Macrovipera, and Daboia have high medical impacts across the Old World. One hotspot for their occurrence and diversity is Türkiye, located on the border between continents, but many of their venoms remain still understudied. Here, we present the venom compositions of seven Turkish viper taxa. By complementary mass spectrometry-based bottom-up and top-down workflows, the venom profiles were investigated on proteomics and peptidomics level. This study includes the first venom descriptions of Vipera berus barani, Vipera darevskii, Montivipera bulgardaghica albizona, and Montivipera xanthina, as well as the first snake venomics profiles of Turkish Macrovipera lebetinus obtusa, and Daboia palaestinae, including an in-depth reanalysis of M. bulgardaghica bulgardaghica venom. Additionally, we identified the modular consensus sequence pEXW(PZ)1-2P(EI)/(KV)PPLE for bradykinin-potentiating peptides in viper venoms. For better insights into variations and potential impacts of medical significance, the venoms were compared against other Palearctic viper proteomes, including the first genus-wide Montivipera venom comparison. This will help the risk assessment of snakebite envenoming by these vipers and aid in predicting the venoms' pathophysiology and clinical treatments.
Assuntos
Proteômica , Venenos de Víboras , Vipera , Animais , Sequência de Aminoácidos , Peptídeos/análise , Peptídeos/química , Filogenia , Proteoma/análise , Proteômica/métodos , Turquia , Venenos de Víboras/química , Vipera/genéticaRESUMO
Snakebite in India is a severe problem as it causes a mortality rate of 58,000 and a disability rate of 140,000 every year which is the highest among any other country. Antivenom is the primary therapy for snakebite, and its manufacturing techniques have essentially stayed unaltered for over a century. Indian polyvalent antivenom, a scientifically validated medicine for treating the toxic effects of snakebites, is available against the venom of the so-called Big Four snakes namely Spectacled cobra (Naja naja), Saw-scaled viper (Echis carinatus), Russell's viper (Daboia russelli) and the Common krait (Bungarus caeruleus), responsible for majority of the deaths in India. India hosts many other species of snakes, including cobras, kraits, saw-scaled vipers, sea snakes, and pit vipers, responsible for clinically severe envenomation. Neutralization strategy has been applied to access the efficacy of antivenoms, crucial for reducing snake bite deaths and disabilities. This review aims to conduct a systematic review and meta-analysis on the neutralization efficiency of the Polyvalent Antivenom (PAV) and focus on the factors that may contribute to the poor recognition of the antivenom towards the venom toxins. Reports focusing on the investigation of antivenom efficacy were searched and collected from several databases. Preclinical studies that reported the neutralization efficacy of the commercial antivenom against the medically important snakes of India were included. The articles were screened based on the inclusion criteria and 8 studies were shortlisted for meta-analysis. Pooled proportion was calculated for the antivenom efficacy reported by the studies and was found to be statistically significant with a 95% confidence interval. The heterogenicity in the venom toxicity and neutralization potency of the antivenom was evident in the overall estimate (proportion) and individual data. We provide comprehensive evidence on antivenom efficacy against medically important snakes from various parts of India which may aid in identifying the gaps in snake envenomation therapy and the need for novel potentially improved treatment of snakebites.
Assuntos
Bungarus , Daboia , Echis , Mordeduras de Serpentes , Serpentes Peçonhentas , Animais , Antivenenos/uso terapêutico , Mordeduras de Serpentes/tratamento farmacológico , Relevância ClínicaRESUMO
As the landscape becomes more urbanized, snakebites have increasingly become uncommon presentations to the emergency departments in Singapore, while snakebites causing significant envenomation are even rarer. In this case report, we discuss a 55-year-old man who had significant envenomation from a Shore Pit Viper (Trimeresurus Purpureomaculatus) and who was successfully treated with haemato-toxic polyvalent antivenom (HPAV). He initially presented with pain, swelling and bleeding over his wound. Due to a deterioration in his coagulation profile, he was given two doses of HPAV which is typically reserved for viperid snakes instead. Following administration of the anti-venom, the patient's coagulation profile improved, and the local soft tissue effects of the venom resolved. He did not manifest any adverse effects and was discharged uneventfully about 72 h after the snakebite. The cross-neutralization potential of HPAV for Shore Pit Viper (Trimeresurus Purpureomaculatus) venom in this case study suggests that there may be a possible common underlying chemical structure and pathophysiology among the venom proteins of various snake species. Given that Trimeresurus-specific antivenom is unavailable in most countries, this cross-neutralization strategy deserves further consideration and evaluation in similar circumstances.
Assuntos
Antivenenos , Venenos de Crotalídeos , Mordeduras de Serpentes , Trimeresurus , Mordeduras de Serpentes/tratamento farmacológico , Mordeduras de Serpentes/terapia , Humanos , Pessoa de Meia-Idade , Masculino , Antivenenos/uso terapêutico , Animais , Venenos de Crotalídeos/antagonistas & inibidoresRESUMO
INTRODUCTION: Snakebite is a public health problem leading to about 58,000 deaths every year in India. Kidney injury subsequent to snakebite envenomation is common with a reported prevalence of up to 32%. The current study aims to elucidate the spectrum of kidney histopathology in acute kidney injury (AKI) cases associated with snake bites. METHODS: We searched seven electronic database studies to identify studies describing the histopathological findings in the kidney with snakebite envenomation. Two reviewers independently conducted titles and abstract screening as well as full-text evaluation for the final inclusion decision. Data were extracted as per the standardized form. We conducted narrative synthesis. Studies done exclusively on autopsy findings, in vitro studies, and case reports were excluded. RESULTS: We retrieved 1464 studies and finally included 28 studies which met the eligibility criteria in the analysis. Most studies were single-centre and the majority were cross-sectional. Overall we included a total of 534 renal biopsies. Russell's viper bite was the most common cause related to AKI. Acute tubular necrosis was the most common finding followed by acute interstitial nephritis, acute cortical necrosis (ACN), and thrombotic microangiopathy (TMA). Vasculitis changes in vessels were rarely reported. Lesions such as ACN and TMA were associated with poor outcomes. CONCLUSION: This analysis supports the notion that renal biopsies are important to guide prognosis and increase our knowledge about post-snake bite AKI pathophysiology.
Assuntos
Injúria Renal Aguda , Mordeduras de Serpentes , Microangiopatias Trombóticas , Humanos , Mordeduras de Serpentes/complicações , Mordeduras de Serpentes/epidemiologia , Mordeduras de Serpentes/diagnóstico , Rim , Injúria Renal Aguda/diagnóstico , Microangiopatias Trombóticas/diagnóstico , Índia/epidemiologia , NecroseRESUMO
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 TRIâ (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.
Assuntos
Antivenenos , Mordeduras de Serpentes , Feminino , Humanos , Adulto , Mordeduras de Serpentes/complicações , Antivenenos/uso terapêutico , Animais , Crotalinae , Venenos de CrotalídeosRESUMO
INTRODUCTION: Bothriechis schlegelii is a Crotaline viperid species of Central America and Northern South America. The characteristics of its envenomation have not been well established. We present clinical characteristics of human cases evaluated and treated in a hospital in southwestern Colombia. METHODS: We evaluated data from patients who suffered Bothriechis schlegelii envenomation and were seen at Fundación Valle del Lili Hospital, Cali, Colombia between 2011 and 2022. RESULTS: Eight patients were included, with a median age of 24 years. Snakebites occurred in rural areas. Six (75%) patients were bitten on the upper extremities in relation to the arboreal habits of this animal. The most common symptoms were pain and edema (N = 8, 100%), ecchymoses (N = 2, 25%), and paresthesia (N = 2, 25%). The most common systemic findings were hypofibrinogenemia (N = 8, 100%) and prolonged prothrombin time in five patients (N = 5, 62.5%). All were treated with polyvalent antivenom for Colombian snakes, with a good response and outcome. CONCLUSIONS: Most bite sites from B. schlegelii were on the upper limbs. All patients had both local manifestations, including edema, pain, and systemic effects with hypofibrinogenemia, but none had systemic bleeding. Every patient received antivenom and had favorable outcomes.
Assuntos
Afibrinogenemia , Bothrops , Crotalinae , Animais , Humanos , Adulto Jovem , Adulto , Colômbia/epidemiologia , Antivenenos/uso terapêutico , Dor/tratamento farmacológico , Dor/etiologia , Edema/etiologiaRESUMO
INTRODUCTION: Snakebite envenomation is a significant life-threatening public health problem in Southeast Asia (SEA). In this region, India reported the largest number of snakebite deaths from 2000 to 2019 (1.2 million), with an average of 58,000 deaths yearly. METHODS: This prospective observational study was carried out among snakebite victims at the emergency department (ED) of a tertiary care public sector hospital in eastern India. RESULTS: A total of 145 cases of venomous snakebite were investigated. More than half (n = 81, 56%) of the snakebite victims were between 17 to 45 years. Most of the snakebite victims were male (68%) and were farmers (53%) by occupation. The majority of snakebites occurred during the daytime (76%) and while outdoors (67%). Most victims sustained a bite on the lower extremity (71%). The peak incidence of snakebites occurred from June to September (69%). Three-quarters of all patients were unaware of the required first aid measures following a snakebite. Among the 145 venomous snakebites, 48 were presumptively identified as the Indian cobra, 32 by the Indian krait, 56 by the Russel's viper, and 9 by saw-scaled viper. The mean duration from the snakebite to the onset of systemic effects in the Indian cobra was 52 ± 14.28â min, 66 ± 18.35â min in the Indian krait, 42 ± 13.47â min in Russel's viper, and 48 ± 16.38â min in saw-scaled viper. Respiratory failure was the commonly observed complication following an elapid envenomation. The mortality rate was 2.1% among the patients treated with antivenom. CONCLUSIONS: Snakebite is considered an occupational hazard in India, commonly affecting the young population in their productive period. The peak incidence was during monsoon season, and the majority had neurotoxic envenomation following an elapid bite (55%) that contributed to the increased mortality and morbidity among young adults. Of the 145 patients, the majority (84%) recovered fully with treatment; 16% of the victims developed morbidity viz cellulitis, respiratory failure, acute renal failure, compartment syndrome, local tissue necrosis, intracerebral hemorrhage, and disseminated intravascular coagulation. Appropriate first aid measures and timely medical intervention can significantly improve the treatment outcome following snakebites.
Assuntos
Mordeduras de Serpentes , Mordeduras de Serpentes/epidemiologia , Mordeduras de Serpentes/mortalidade , Humanos , Índia/epidemiologia , Masculino , Estudos Prospectivos , Adulto , Feminino , Pessoa de Meia-Idade , Adolescente , Adulto Jovem , Antivenenos/uso terapêutico , Incidência , Criança , Animais , Serviço Hospitalar de Emergência/estatística & dados numéricos , IdosoRESUMO
Snakebites in unusual anatomical locations may lead to life-threatening consequences. Merrem's hump-nosed viper (Hypnale hypnale) is a medically important snake in Sri Lanka and India that causes many bites and envenomings. Their bites occur almost exclusively on upper and lower limbs and commonly result in local effects, with some patients developing systemic envenoming. No antivenom is available for treating envenoming by H. hypnale. We report an unusual case of H. hypnale bite on the tongue of a 10-month-old infant resulting in rapid local swelling of the tongue and floor of the mouth, requiring prompt intervention to prevent life-threatening upper airway obstruction. Early tracheostomy prevented upper airway obstruction and, along with supportive steroid therapy and antibiotics, led to a complete resolution of the local effects of the infant without permanent disability, despite the unavailability of antivenom.
Assuntos
Obstrução das Vias Respiratórias , Mordeduras de Serpentes , Humanos , Mordeduras de Serpentes/complicações , Mordeduras de Serpentes/terapia , Lactente , Obstrução das Vias Respiratórias/etiologia , Animais , Masculino , Língua , Crotalinae , Antivenenos/uso terapêutico , Antibacterianos/uso terapêutico , Sri LankaRESUMO
In the Brazilian Amazon, snakebite envenomations (SBEs) disproportionately affect Indigenous populations, and have a significantly higher incidence and lethality than in non-Indigenous populations. This qualitative study describes the Indigenous and biomedical healthcare domains for SBE care from the perspective of the Indigenous medical and nursing students in Manaus, Western Brazilian Amazon. In-depth interviews were conducted with five Indigenous students from the Amazonas State University, between January and December 2021. The interviews were analyzed using inductive content analysis. We organized an explanatory model with five themes: (1) participants' identities; (2) causality levels in Indigenous and biomedical systems; (3) therapeutic itineraries in Indigenous and biomedical systems; (4) ideological implications of adding biomedical devices to Indigenous healing systems; and (5) therapeutic failure in and efficacy of Indigenous and biomedical systems. From a noncolonial perspective and seeking to increase the quality and acceptability of health care for the Indigenous populations of the Brazilian Amazon, the training of Indigenous health professionals presents itself as a promising strategy. For this goal, universities should serve as empowering settings for Indigenous health students that support them in their growth and development, raise their awareness of injustice, and catalyze change toward a culturally adapted and effective service for the users.
Assuntos
Pesquisa Qualitativa , Mordeduras de Serpentes , Estudantes de Medicina , Estudantes de Enfermagem , Humanos , Mordeduras de Serpentes/terapia , Mordeduras de Serpentes/tratamento farmacológico , Estudantes de Enfermagem/psicologia , Estudantes de Enfermagem/estatística & dados numéricos , Brasil , Feminino , Estudantes de Medicina/psicologia , Estudantes de Medicina/estatística & dados numéricos , Masculino , Adulto , Serviços de Saúde do Indígena/tendências , Entrevistas como Assunto/métodosRESUMO
Snakebite envenomation (SBE) in horses can have devastating outcomes. Tissue damage, cardiotoxicity, coagulopathy, and neurotoxicity can be concerns with SBE. Understanding the actions of venom components is important in developing a successful treatment plan. Antivenom is the mainstay of treatment. Long-term deleterious effects can occur including cardiac dysfunction and lameness.
Assuntos
Transtornos da Coagulação Sanguínea , Doenças dos Cavalos , Mordeduras de Serpentes , Animais , Cavalos , Mordeduras de Serpentes/complicações , Mordeduras de Serpentes/veterinária , Doenças dos Cavalos/etiologia , Doenças dos Cavalos/terapia , Antivenenos/uso terapêutico , Transtornos da Coagulação Sanguínea/veterináriaRESUMO
OBJECTIVES: To evaluate the safety and efficacy of expired lyophilized snake antivenom of Thai origin during a medical emergency in 2020/2021 in Lao People's Democratic Republic. METHODS: Observational case series of patients with potentially life-threatening envenoming who consented to the administration of expired antivenom between August 2020 and May 2022. RESULTS: A total of 31 patients received the expired antivenom. Malayan pit vipers (Calloselasma rhodostoma) were responsible for 26 (84%) cases and green pit vipers (Trimeresurus species) for two cases (6%). In three patients (10%) the responsible snake could not be identified. Of these, two presented with signs of neurotoxicity and one with coagulopathy. A total of 124 vials of expired antivenom were administered. Fifty-nine vials had expired 2-18 months earlier, 56 vials 19-36 months and nine vials 37-60 months before. Adverse effects of variable severity were observed in seven (23%) patients. All 31 patients fully recovered from systemic envenoming. CONCLUSIONS: Under closely controlled conditions and monitoring the use of expired snake antivenom proved to be effective and safe. Discarding this precious medication is an unnecessary waste, and it could be a valuable resource in ameliorating the current shortage of antivenom. Emergency use authorization granted by health authorities and preclinical testing of expired antivenoms could provide the support and legal basis for such an approach.
Assuntos
Antivenenos , Mordeduras de Serpentes , Humanos , Antivenenos/uso terapêutico , Mordeduras de Serpentes/tratamento farmacológico , LaosRESUMO
BACKGROUND: This study aimed to assess the predictive value of NLR, PLR, and MPV time series for diagnosis and prognosis of hemotoxic snakebite envenomation. METHODS: This is a prospective study among snakebite patients admitted to the Poison Control Center of Ain Shams University Hospitals and Assiut University Hospitals from the beginning of July 2019 to the end of October 2021. Patients were classified according to their clinical severity into three groups: mild, moderate, and severe. RESULTS: The maximum incidence of snakebite was found in males (95%) from rural areas (80%); at lower limbs (70%); at night (51%); and during the autumn season (43.3%). The admission NLR and PLR can predict hemotoxic snakebite envenomation with an AUC of 0.940 and 0.569. The combination of NLR with PLR can develop a more predominant prediction of snakebite envenomation with an area under the curve (AUC) of 0.979. Furthermore, higher admission NLR and PLR levels are associated with prolonged hospital stays. CONCLUSION: While NLR and PLR levels may be helpful in the diagnosis of snakebite, MPV plays no part in the prognosis of snakebite patients. Serial NLR, PLR initially, at 24 hours, and predischarge can be used to evaluate the early treatment response.
Assuntos
Neutrófilos , Mordeduras de Serpentes , Masculino , Humanos , Volume Plaquetário Médio , Mordeduras de Serpentes/diagnóstico , Contagem de Leucócitos , Fatores de Tempo , Estudos Prospectivos , Contagem de Plaquetas , Plaquetas , Prognóstico , Linfócitos , Estudos RetrospectivosRESUMO
Snakebite envenoming is currently considered a neglected tropical disease, which affects over 5 million people worldwide, and causes almost 150 000 deaths every year, as well as severe injuries, amputations and other sequelae. Snakebite envenoming in children, although proportionally less frequent, is generally more severe, and represents an important challenge for pediatric medicine, since they often result in worse outcomes. In Brazil, given its ecological, geographic and socioeconomic characteristics, snakebites are considered an important health problem, presenting approximately 30 000 victims per year, approximately 15% of them in children. Even with low snakebite incidence, children tend to have higher snakebite severity and complications due to the small body mass and same venom volume inoculated in comparison to adults, even though, due to the lack of epidemiological information about pediatric snakebites and induced injuries, it is difficult to measure the treatment effectiveness, outcomes and quality of emergency medical services for snakebites in children. In this review, we report how Brazilian children are affected by snakebites, describing the characteristics of this affected population, clinical aspects, management, outcomes and main challenges.
Assuntos
Serviços Médicos de Emergência , Mordeduras de Serpentes , Adulto , Criança , Humanos , Mordeduras de Serpentes/epidemiologia , Mordeduras de Serpentes/terapia , Brasil/epidemiologia , Incidência , Fatores Socioeconômicos , Doenças NegligenciadasRESUMO
BACKGROUND: Of the 8000-10,000 snake envenomations evaluated in U.S. emergency departments (ED) annually, approximately 1% are due to non-native snakes. We describe a 26-year-old man who was bitten by his captive black mamba (Dendroaspis polylepis) as he was packing it up for transport to another snake collector. CASE REPORT: The patient presented to the ED 1 h after being bitten on the forearm, complaining of left arm pain, oral paresthesias, and dyspnea. His vital signs: heart rate 96 beats/min, blood pressure 167/101 mm Hg, temperature 36.7°C (97.9°F), respiratory rate 20 breaths/min, and room air oxygen saturation 100%. Two mildly tender puncture wounds without swelling or ecchymosis were found on the posterior aspect of the forearm. Over the ensuing 30 min his dyspnea worsened, and he developed objective weakness. He was intubated and placed on mechanical ventilation. He was treated with atropine 2 mg for bronchorrhea. Five vials of South African Vaccine Producers (Johannesburg, South Africa) polyvalent antivenom were administered 2.5 h post-bite and the patient was admitted to the intensive care unit. He was extubated 18 h post-envenomation and discharged the following day. He has remained asymptomatic since leaving the hospital. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: The primary manifestations of D. polylepis envenomings are neurological. Initial signs may include paresthesias, dysarthria, dysphagia, and ptosis. Progressive descending paralysis leading to respiratory failure develops within 60 min. Muscarinic features are frequently observed. Cardiotoxicity and hematologic laboratory abnormalities may be present. Although pain is common, significant local tissue injury does not occur. In addition to supportive care, several non-native antivenoms are indicated for D. polylepis envenomations. Black mamba envenomings differ from the native snakebites with which U.S. physicians are familiar. Rapid, progressive neurological toxicity and muscarinic features are most common. Treatment consists of supportive care and appropriate antivenom administration.
Assuntos
Dendroaspis , Insuficiência Respiratória , Mordeduras de Serpentes , Masculino , Animais , Humanos , Antivenenos , Parestesia , África do Sul , Mordeduras de Serpentes/diagnóstico , Serpentes , Dispneia , Dor , Oxigênio , ColinérgicosRESUMO
There are high mortality and morbidity rates from poisonous snakebites globally. Many medicinal plants are locally used for snakebite treatment in Uganda. This study aimed to determine the in vitro anti-venom activities of aqueous extract and oils of Toona ciliata against Naja melanoleuca venom. A mixture of venom and extract was administered intramuscularly in rats. Anticoagulant, antiphospholipase A2 (PLA2) inhibition assay, and gel electrophoresis for anti-venom activities of oils were done. The chemical constituents of the oils of ciliata were identified using Gas chromatography-tandem mass spectroscopy (GC-MS/MS). The LD50 of the venom was 0.168 ± 0.21 µg/g. The venom and aqueous extract mixture (1.25 µg/g and 3.5 mg/g) did not cause any rat mortality, while the control with venom only (1.25 µg/g) caused death in 1 h. The aqueous extract of T. ciliata inhibited the anticoagulation activity of N. melanoleuca venom from 18.58 min. to 4.83 min and reduced the hemolytic halo diameter from 24 to 22 mm. SDS-PAGE gel electrophoresis showed that oils completely cleared venom proteins. GC-MS/MS analysis showed that the oils had sesquiterpene hydrocarbons (60%) in the volatile oil (VO) and oxygenated sesquiterpenes (48.89%) in the non-volatile oils (NVO). Some major compounds reported for the first time in T. ciliata NVOs were: Rutamarin (52.55%), ß-Himachalol (9.53%), Girinimbine (6.68%) and Oprea1 (6.24%). Most compounds in the VO were reported for the first time in T. ciliata, including the major ones Santalene (8.55%) and Himachal-7-ol (6.69%). The result showed that aqueous extract and oils of T. ciliata have anti-venom/procoagulant activities and completely neutralized the venom. We recommend a study on isolation and testing the pure compounds against the same venom.
Assuntos
Antivenenos , Óleos Voláteis , Ratos , Animais , Antivenenos/farmacologia , Venenos Elapídicos/análise , Toona , Espectrometria de Massas em Tandem , Óleos Voláteis/farmacologia , ÁguaRESUMO
Snake envenomation is a rare incident during pregnancy and potentially challenging to manage. Snakebites in pregnancy may lead to several complications such as teratogenicity, miscarriage, antepartum hemorrhage, and even intrauterine fetal death. Here, we report a case of a pregnant woman who presented to our emergency department with signs of systemic envenomation following an Indian cobra bite on her foot, highlighting the key obstetric and wound management challenges. She complained of severe pain at the site of the bite and progressive swelling, abdominal pain, and multiple episodes of vomiting, which started 45 min after the bite. She received 10 vials of polyvalent antivenom from a primary hospital and was then referred to our center. The patient underwent emergency cesarean section and later fasciotomy with free-flap reconstruction at the bitten site due to local tissue necrosis. The case was successfully managed by a multidisciplinary team consisting of an emergency physician, obstetrician, and plastic surgeon, saving 2 lives and the limb of the patient.
Assuntos
Elapidae , Mordeduras de Serpentes , Humanos , Animais , Feminino , Gravidez , Gestantes , Cesárea , Mordeduras de Serpentes/complicações , Mordeduras de Serpentes/terapia , Antivenenos/uso terapêutico , Dor Abdominal/complicaçõesRESUMO
Snakebite envenoming is a neglected tropical disease disproportionately affecting the rural and marginalized population in low-middle-income countries. The saw-scaled viper (Echis carinatus) is a clinically important snake that causes serious morbidity and mortality in the Indian subcontinent. Even though it is within the so-called big-four snakes against which polyvalent antivenom is available throughout India, reports of antivenom ineffectiveness are emerging in saw-scaled viper envenoming, especially around Jodhpur, Rajasthan, India. This case report highlights a patient with saw-scaled viper envenoming with an ineffective antivenom response complicated by acute kidney injury as well as local and systemic bleeding complications, which subsequently resulted in a pelvic hematoma that compressed the lumbosacral nerves, causing lower-limb weakness and sensory deficits. He was successfully managed with hematoma aspiration and supportive care. This case brings into focus the challenges of managing saw-scaled viper envenoming in this region with antivenom ineffectiveness, resulting in delayed and significant coagulopathy and its complications leading to prolonged hospital stay and morbidity. Our report spotlights less emphasized aspects of long-term morbidity in snakebite survivors, such as loss of working days and productivity. We also highlight the need for an organized system of long-term follow-up of snakebite survivors to screen for possible complications and manage them early.