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Isbister GK, Jenkins S, Downes MA, Fakes K, Buckley NA. A randomized controlled trial and prospective cohort investigating antivenom for red-bellied black snake envenomation. Clin Toxicol (Phila) 2024; 62:343-351. [PMID: 38913734 DOI: 10.1080/15563650.2024.2367677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Accepted: 06/07/2024] [Indexed: 06/26/2024]
Abstract
INTRODUCTION Antivenom is first line treatment for snake envenomation worldwide, despite few placebo controlled clinical trials demonstrating effectiveness. We aimed to investigate whether early antivenom in red-bellied black snake (Pseudechis porphyriacus) bites would prevent systemic myotoxicity. METHODS We undertook a multicentre randomized placebo-controlled trial of antivenom for red-bellied black snake bites with patients recruited from the Australian Snakebite Project (July 2014 to June 2020). In addition, we report all patients with red-bellied black snake bites during the same period, comparing the same outcomes. Patients over 2 years of age with definite red-bellied black snake bites and early systemic effects were randomized to receive 50 per cent glucose (placebo) or tiger snake antivenom within 6 hours post-bite, or in the cohort group received antivenom determined by the treating clinician. The primary outcome was the proportion of patients with myotoxicity (peak creatine kinase activity >1,000 U/L). Secondary outcomes were: area under the curve of total creatine kinase elevation over 48 hours, presence of venom post-antivenom, and adverse reactions. We analyzed both the randomized control trial patients and the combination of randomized control trial and cohort patients. RESULTS Fifteen patients were recruited to the randomized controlled trial, and a cohort of 68 patients who were not randomized were included in the analysis. After treatment, two of seven patients given placebo had a peak creatine kinase activity >1,000 U/L versus none of the eight given antivenom (difference in favour of antivenom; 29 per cent; 95 per cent confidence interval:-18 per cent to +70 per cent; P = 0.2). The median area under the curve of total creatine kinase elevation over 48 hours in patients given placebo was 0 U/L*h (interquartile range: 0-124 U/L*h), which was not significantly different to those given antivenom: 197 U/L*h (interquartile range: 0-66,353 U/L*h; P = 0.26). Venom was not detected post-antivenom in six patients with measured venom concentrations given antivenom. Two patients given antivenom had immediate hypersensitivity reactions, one severe anaphylaxis, and another had serum sickness. Combining randomized and not randomized patients, three of 36 (8 per cent) administered antivenom less than 6 hours post-bite had a peak creatine kinase activity >1,000 U/L versus 17/47 (36 per cent) patients not receiving antivenom less than 6 hours post-bite (difference in favour of antivenom 29 per cent; 95 per cent confidence interval: 8 per cent to 44 per cent; P < 0.004). Overall, 13/36 (36 per cent) patients administered antivenom within 6 hours had hypersensitivity reactions, six severe anaphylaxis (17 per cent). DISCUSSION We found that early antivenom was effective in red-bellied black snake bites, and only three patients need to be given antivenom within 6 hours to prevent myotoxicity in one (number needed to treat = 3). However, one in three patients administered antivenom developed a hypersensitivity reaction, and one in six had severe anaphylaxis. The major limitation of this study was the small number of patients recruited to the randomized controlled trial. CONCLUSION Administration of antivenom in red-bellied black snake envenomation within 6 hours post-bite appeared to decrease the proportion of patients with myotoxicity, but a third of patients had adverse reactions.
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Affiliation(s)
- Geoffrey K Isbister
- Clinical Toxicology Research Group, University of Newcastle, Newcastle, Australia
- Department of Clinical Toxicology, Newcastle, Australia
- New South Wales Poison Information Centre, Childrens Hospital Westmead, Sydney, Australia
| | - Shane Jenkins
- Clinical Toxicology Research Group, University of Newcastle, Newcastle, Australia
| | - Michael A Downes
- Clinical Toxicology Research Group, University of Newcastle, Newcastle, Australia
- Department of Clinical Toxicology, Newcastle, Australia
- New South Wales Poison Information Centre, Childrens Hospital Westmead, Sydney, Australia
| | - Kellie Fakes
- Clinical Toxicology Research Group, University of Newcastle, Newcastle, Australia
| | - Nicholas A Buckley
- Department of Clinical Toxicology, Newcastle, Australia
- New South Wales Poison Information Centre, Childrens Hospital Westmead, Sydney, Australia
- Clinical Pharmacology & Toxicology Research Group, School of Medical Sciences, University of Sydney
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Johnston CI, Silva A, Hodgson W, Isbister GK. Investigating skeletal muscle biomarkers for the early detection of Australian myotoxic snake envenoming: an animal model pilot study. Clin Toxicol (Phila) 2024; 62:280-287. [PMID: 38804832 DOI: 10.1080/15563650.2024.2349690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 04/25/2024] [Indexed: 05/29/2024]
Abstract
INTRODUCTION Myotoxicity is an important toxidrome that can occur with envenoming from multiple Australian snake types. Early antivenom administration is an important strategy to reduce the incidence and severity of myotoxicity. The current gold standard biomarker, serum creatine kinase activity, does not rise early enough to facilitate early antivenom administration. Several other skeletal muscle biomarkers have shown promise in other animal models and scenarios. The aim of this study was to examine the predictive values of six skeletal muscle biomarkers in a rat model of Australian snake myotoxicity. METHODS Sprague-Dawley rats were anaesthetised and administered either Pseudechis porphyriacus (red-bellied black snake) or Notechis scutatus (tiger snake) venom, or normal saline via intramuscular injection. Blood samples were collected. Assays were performed for serum creatine kinase skeletal muscle troponin-I concentration, skeletal muscle troponin-C concentration, myoglobin activity, skeletal muscle myosin light chain-1 concentration, and creatine kinase-MM activity. Serum markers were plotted against time, with comparison of area under the concentration (or activity)-time curve. The predictive values of six skeletal muscle biomarkers were examined using receiver operating characteristic curves. RESULTS There was no difference in area under the serum creatine kinase activity-time curve between venom and control groups. Serum creatine kinase-MM activity rose early in the venom treated rats, which had a significantly greater area under the serum activity-time curve. No difference in area under the serum concentration-time curve was demonstrated for the other biomarkers. Creatine kinase-MM activity had a superior predictive values than creatine kinase activity at 0-4 hours and 0-10 hours after venom administration, as indicated by area under the receiver operating characteristic curves (95 per cent confidence intervals) of 0.91 (0.78-1.00) and 0.88 (0.73-1.00) versus 0.79 (0.63-0.95) and 0.66 (0.51-0.80). DISCUSSION The limitations of serum creatine kinase activity in early detection of myotoxicity were demonstrated in this rat model. CONCLUSION Serum creatine kinase-MM activity was superior for early detection of Australian myotoxic snake envenoming.
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Affiliation(s)
| | - Anjana Silva
- Department of Parasitology, Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Anuradhapura, Sri Lanka
| | - Wayne Hodgson
- Monash Venom Group, Department of Pharmacology, Biomedical Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Geoffrey K Isbister
- Clinical Toxicology Research Group, University of Newcastle, Newcastle, NSW, Australia
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Isbister GK. The critical time period for administering antivenom: golden hours and missed opportunities. Clin Toxicol (Phila) 2024; 62:277-279. [PMID: 38804828 DOI: 10.1080/15563650.2024.2352026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Accepted: 05/01/2024] [Indexed: 05/29/2024]
Abstract
INTRODUCTION Antivenom is widely accepted as an effective treatment for snake envenomation. This is despite very limited evidence supporting clinical effectiveness for major envenomation syndromes, and is mainly based on pre-clinical studies and observational studies without control groups. EFFECTIVENESS OF EARLY ANTIVENOM Although antivenom exhibits efficacy by binding to snake toxins and preventing toxic injury in animals if pre-mixed with venom, this efficacy does not always translate to clinical effectiveness. There are many irreversible venom mediated effects that antivenom cannot neutralise or reverse, such as pre-synaptic neurotoxicity and myotoxicity. Fortunately, early antivenom appears to prevent some of these. PRACTICALITIES OF ADMINISTERING ANTIVENOM EARLY With good evidence that early antivenom prevents some envenomation syndromes, the time between bite and antivenom administration must be reduced. This requires improving the initial assessment of snakebite patients, and improving early decision making based on clinical effects. CONCLUSION Until there are improved, simplified, easy to use, rapid and inexpensive tests, whether available in the laboratory or preferably at the bedside that identify systemic envenomation, the key to early antivenom administration is early assessment and decision making based on systemic symptoms, including nausea, vomiting, headache and abdominal pain.
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Gilliam LL, Gilliam J, Samuel SP, Carter RW, Ritchey J, Bulfone T, Gutiérrez JM, Williams DJ, Durkin DM, Stephens SI, Lewin MR. Oral and IV Varespladib Rescue Experiments in Juvenile Pigs with Weakness Induced by Australian and Papuan Oxyuranus scutellatus Venoms. Toxins (Basel) 2023; 15:557. [PMID: 37755983 PMCID: PMC10537020 DOI: 10.3390/toxins15090557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 08/02/2023] [Accepted: 08/17/2023] [Indexed: 09/28/2023] Open
Abstract
Antivenom is currently the standard-of-care treatment for snakebite envenoming, but its efficacy is limited by treatment delays, availability, and in many cases, species specificity. Many of the rapidly lethal effects of envenoming are caused by venom-derived toxins, such as phospholipase A2 (sPLA2); therefore, small molecule direct toxin inhibitors targeting these toxins may have utility as initial and adjunct therapies after envenoming. Varespladib (intravenous, IV) and varespladib-methyl (oral) have been shown to potently inhibit sPLA2s from snake venoms in murine and porcine models, thus supporting their further study as potential treatments for snakebite envenoming. In this pilot study, we tested the ability of these compounds to reverse neurotoxic effects of venom from the Australian and Papuan taipan (Oxyuranus scutellatus) subspecies in juvenile pigs (Sus domesticus). The mean survival time for control animals receiving Australian taipan venom (0.03 mg/kg, n = 3) was 331 min ± 15 min; for those receiving Papuan taipan venom (0.15 mg/kg, n = 3) it was 178 ± 31 min. Thirteen pigs received Australian taipan venom and treatment with either IV or oral varespladib (or with IV to oral transition) and all 13 survived the duration of the study (≥96 h). Eight pigs received Papuan taipan venom followed by treatment: Briefly: Two animals received antivenom immediately and survived to the end of the study. Two animals received antivenom treatment delayed 45 min from envenoming and died within 4 h. Two animals received similarly delayed antivenom treatment and were rescued by varespladib. Two animals were treated with varespladib alone after a 45-min delay. Treatment with varespladib only was effective but required repeat dosing over the course of the study. Findings highlight both the importance of early treatment and, as well, a half-life for the investigational inhibitors now in Phase II clinical trials for snakebite. Varespladib rapidly reversed weakness even when administered many hours post-envenoming and, overall, our results suggest that varespladib and varespladib-methyl could be efficacious tools in the treatment of sPLA2-induced weakness from Oxyuranus envenoming. Further clinical study as initial therapy and as potential method of rescue from some types of antivenom-resistant envenomings are supported by these data.
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Affiliation(s)
- Lyndi L. Gilliam
- Department of Veterinary Clinical Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA; (L.L.G.); (J.G.); (J.R.)
| | - John Gilliam
- Department of Veterinary Clinical Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA; (L.L.G.); (J.G.); (J.R.)
| | - Stephen P. Samuel
- Division of Research Ophirex, Inc., Corte Madera, CA 94925, USA; (S.P.S.); (R.W.C.); (S.I.S.)
| | - Rebecca W. Carter
- Division of Research Ophirex, Inc., Corte Madera, CA 94925, USA; (S.P.S.); (R.W.C.); (S.I.S.)
| | - Jerry Ritchey
- Department of Veterinary Clinical Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA; (L.L.G.); (J.G.); (J.R.)
| | - Tommaso Bulfone
- Center for Exploration and Travel Health, California Academy of Sciences, San Francisco, CA 94118, USA; (T.B.)
- School of Medicine, University of California, San Francisco, CA 94143, USA
| | - José María Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501-2060, Costa Rica;
| | - David J. Williams
- Regulation and Prequalification Department (RPQ) at the World Health Organization (WHO), 1211 Geneva, Switzerland;
| | - Daniela M. Durkin
- Center for Exploration and Travel Health, California Academy of Sciences, San Francisco, CA 94118, USA; (T.B.)
| | - Sally I. Stephens
- Division of Research Ophirex, Inc., Corte Madera, CA 94925, USA; (S.P.S.); (R.W.C.); (S.I.S.)
| | - Matthew R. Lewin
- Division of Research Ophirex, Inc., Corte Madera, CA 94925, USA; (S.P.S.); (R.W.C.); (S.I.S.)
- Center for Exploration and Travel Health, California Academy of Sciences, San Francisco, CA 94118, USA; (T.B.)
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Knudsen C, Jürgensen JA, D Knudsen P, Oganesyan I, Harrison JA, Dam SH, Haack AM, Friis RUW, Vitved L, Belfakir SB, Ross GMS, Zenobi R, H Laustsen A. Prototyping of a lateral flow assay based on monoclonal antibodies for detection of Bothrops venoms. Anal Chim Acta 2023; 1272:341306. [PMID: 37355315 DOI: 10.1016/j.aca.2023.341306] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 04/30/2023] [Indexed: 06/26/2023]
Abstract
BACKGROUND Brazil is home to a multitude of venomous snakes; perhaps the most medically relevant of which belong to the Bothrops genus. Bothrops spp. are responsible for roughly 70% of all snakebites in Brazil, and envenomings caused by their bites can be treated with three types of antivenom: bothropic antivenom, bothro-lachetic antivenom, and bothro-crotalic antivenom. The choice to administer antivenom depends on the severity of the envenoming, while the choice of antivenom depends on availability and on how certain the treating physician is that the patient was bitten by a bothropic snake. The diagnosis of a bothropic envenoming can be made based on expert identification of the dead snake or a photo thereof or based on a syndromic approach wherein the clinician examines the patient for characteristic manifestations of envenoming. This approach can be very effective but requires staff that has been trained in clinical snakebite management, which, unfortunately, far from all relevant staff has. RESULTS In this article, we describe a prototype of the first lateral flow assay (LFA) capable of detecting venoms from Brazilian Bothrops spp. The monoclonal antibodies for the assay were generated using hybridoma technology and screened in sandwich enzyme-linked immunosorbent assays (ELISAs) to identify Bothrops spp.-specific antibody sandwich pairs. The prototype LFA is able to detect venom from several Bothrops spp. The LFA has a limit of detection (LoD) of 9.5 ng/mL in urine, when read with a commercial reader, and a visual LoD of approximately 25 ng/mL. SIGNIFICANCE The work presented here serves as a proof of concept for a genus-specific venom detection kit that could support physicians in diagnosing Bothrops envenomings. Although further optimisation and testing is needed before the LFA can find clinical use, such a device could aid in decentralising antivenoms in the Brazilian Amazon and help ensure optimal snakebite management for even more victims of this highly neglected disease.
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Affiliation(s)
- Cecilie Knudsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark; BioPorto Diagnostics A/S, Hellerup, Denmark; VenomAid Diagnostics ApS, Kongens Lyngby, Denmark.
| | | | | | - Irina Oganesyan
- Department of Chemistry and Applied Biosciences, ETH Zürich, Zürich, Switzerland
| | - Julian A Harrison
- Department of Chemistry and Applied Biosciences, ETH Zürich, Zürich, Switzerland
| | - Søren H Dam
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark; VenomAid Diagnostics ApS, Kongens Lyngby, Denmark
| | - Aleksander M Haack
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark; VenomAid Diagnostics ApS, Kongens Lyngby, Denmark
| | - Rasmus U W Friis
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark; VenomAid Diagnostics ApS, Kongens Lyngby, Denmark
| | - Lars Vitved
- Cancer and Inflammation, Department of Molecular Medicine, University of Southern, Denmark
| | - Selma B Belfakir
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark; VenomAid Diagnostics ApS, Kongens Lyngby, Denmark
| | | | - Renato Zenobi
- Department of Chemistry and Applied Biosciences, ETH Zürich, Zürich, Switzerland
| | - Andreas H Laustsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark; VenomAid Diagnostics ApS, Kongens Lyngby, Denmark.
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Kakati H, Giri S, Patra A, Taye SJ, Agarwalla D, Boruah H, Choudhary G, Kalita B, K Mukherjee A. A retrospective analysis of epidemiology, clinical features of envenomation, and in-patient management of snakebites in a model secondary hospital of Assam, North-east India. Toxicon 2023; 230:107175. [PMID: 37257518 DOI: 10.1016/j.toxicon.2023.107175] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 05/02/2023] [Accepted: 05/26/2023] [Indexed: 06/02/2023]
Abstract
Assam, a Northeastern State of India, is inhabited by several venomous snake species causing substantial morbidity and mortality. The data on the epidemiology of snakebites and their management is underreported in this region. Hence, a secondary health-based retrospective study was carried out at Demow Model Hospital, Sivasagar, Assam, to evaluate the clinical and epidemiological profile of snakebite cases reported in this rural hospital and their management. Snakebites occurring between April 2018 to August 2022 were reviewed based on socio-demographic details of the patient, clinical symptoms, and treatment using a standard questionnaire. Out of the 1011 registered snakebite cases, 139 patients (13.7%) counted for venomous bites, among which 92 patients (66.19%) accounted for viper bites (green pit viper and Salazar's pit viper), and 30 patients (21.5%) were bitten by elapid snakes (Indian monocled Cobra, banded krait, and greater/lesser black krait). A maximum number of snakebite cases (80.5%) were reported from the interior rural villages and documented from July to September (51.3%). Elapid snake envenomed patients, except one, were successfully treated with commercial antivenom, neostigmine, and glycopyrrolate. Because commercial polyvalent antivenom against "Big Four" venomous snakes of India showed poor neutralization of pit-vipers envenomation; therefore, pit-viper bite patients were treated with repurposed drugs magnesium sulfate and glycerin compression dressing. Adverse serum reactions were reported only in 3 (11.1%) cases. The preventive measures and facilities adopted at the Demow Model Hospital significantly reduce snakebite death and morbidity; therefore, they can be s practised across various states in India as a prototype.
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Affiliation(s)
- Hirakjyoti Kakati
- Department of Molecular Biology and Biotechnology, School of Sciences, Tezpur University, Tezpur, 784028, Assam, India
| | - Surajit Giri
- Demow Government Community Health Centre, Raichai, Konwar Dihingia Gaon, Sivasagar, Assam, India.
| | - Aparup Patra
- Institute of Advanced Studies in Science and Technology, Vigyan Path Garchuk, Paschim Boragaon, Guwahati, 781035, Assam, India
| | - Simanta J Taye
- Demow Government Community Health Centre, Raichai, Konwar Dihingia Gaon, Sivasagar, Assam, India
| | - Deepak Agarwalla
- Demow Government Community Health Centre, Raichai, Konwar Dihingia Gaon, Sivasagar, Assam, India
| | - Hridoy Boruah
- Demow Government Community Health Centre, Raichai, Konwar Dihingia Gaon, Sivasagar, Assam, India
| | - Gaurav Choudhary
- Demow Government Community Health Centre, Raichai, Konwar Dihingia Gaon, Sivasagar, Assam, India
| | - Bhargab Kalita
- Amrita School of Nanosciences and Molecular Medicine, Amrita Institute of Medical Sciences and Research Centre, Amrita Vishwa Vidyapeetham, Ponekkara, Kochi, 682041, Kerala, India
| | - Ashis K Mukherjee
- Department of Molecular Biology and Biotechnology, School of Sciences, Tezpur University, Tezpur, 784028, Assam, India; Institute of Advanced Studies in Science and Technology, Vigyan Path Garchuk, Paschim Boragaon, Guwahati, 781035, Assam, India.
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Antivenom availability, delays and use in Australia. Toxicon X 2023; 17:100145. [DOI: 10.1016/j.toxcx.2022.100145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/30/2022] [Accepted: 12/02/2022] [Indexed: 12/13/2022] Open
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In Vitro Efficacy of Antivenom and Varespladib in Neutralising Chinese Russell's Viper ( Daboia siamensis) Venom Toxicity. Toxins (Basel) 2023; 15:toxins15010062. [PMID: 36668882 PMCID: PMC9864994 DOI: 10.3390/toxins15010062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/08/2023] [Accepted: 01/09/2023] [Indexed: 01/13/2023] Open
Abstract
The venom of the Russell's viper (Daboia siamensis) contains neurotoxic and myotoxic phospholipase A2 toxins which can cause irreversible damage to motor nerve terminals. Due to the time delay between envenoming and antivenom administration, antivenoms may have limited efficacy against some of these venom components. Hence, there is a need for adjunct treatments to circumvent these limitations. In this study, we examined the efficacy of Chinese D. siamensis antivenom alone, and in combination with a PLA2 inhibitor, Varespladib, in reversing the in vitro neuromuscular blockade in the chick biventer cervicis nerve-muscle preparation. Pre-synaptic neurotoxicity and myotoxicity were not reversed by the addition of Chinese D. siamensis antivenom 30 or 60 min after venom (10 µg/mL). The prior addition of Varespladib prevented the neurotoxic and myotoxic activity of venom (10 µg/mL) and was also able to prevent further reductions in neuromuscular block and muscle twitches when added 60 min after venom. The addition of the combination of Varespladib and antivenom 60 min after venom failed to produce further improvements than Varespladib alone. This demonstrates that the window of time in which antivenom remains effective is relatively short compared to Varespladib and small-molecule inhibitors may be effective in abrogating some activities of Chinese D. siamensis venom.
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Bickler PE, Abouyannis M, Bhalla A, Lewin MR. Neuromuscular Weakness and Paralysis Produced by Snakebite Envenoming: Mechanisms and Proposed Standards for Clinical Assessment. Toxins (Basel) 2023; 15:49. [PMID: 36668869 PMCID: PMC9861841 DOI: 10.3390/toxins15010049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 11/23/2022] [Accepted: 12/10/2022] [Indexed: 01/11/2023] Open
Abstract
Respiratory and airway-protective muscle weakness caused by the blockade of neuromuscular transmission is a major cause of early mortality from snakebite envenoming (SBE). Once weakness is manifest, antivenom appears to be of limited effectiveness in improving neuromuscular function. Herein, we review the topic of venom-induced neuromuscular blockade and consider the utility of adopting clinical management methods originally developed for the safe use of neuromuscular blocking agents by anesthesiologists in operating rooms and critical care units. Failure to quantify neuromuscular weakness in SBE is predicted to cause the same significant morbidity that is associated with failure to do so in the context of using a clinical neuromuscular block in surgery and critical care. The quantitative monitoring of a neuromuscular block, and an understanding of its neurophysiological characteristics, enables an objective measurement of weakness that may otherwise be overlooked by traditional clinical examination at the bedside. This is important for the initial assessment and the monitoring of recovery from neurotoxic envenoming. Adopting these methods will also be critical to the conduct of future clinical trials of toxin-inhibiting drugs and antivenoms being tested for the reversal of venom-induced neuromuscular block.
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Affiliation(s)
- Philip E. Bickler
- Center for Exploration and Travel Health, California Academy of Science, San Francisco, CA 94118, USA
- Anesthesia and Perioperative Care, University of California at San Francisco, 513 Parnassus Ave, Medical Science Room S-257, San Francisco, CA 94143-0542, USA
| | - Michael Abouyannis
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - Ashish Bhalla
- Department of Internal Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Matthew R. Lewin
- Center for Exploration and Travel Health, California Academy of Science, San Francisco, CA 94118, USA
- Ophirex, Inc., Corte Madera, CA 94925, USA
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A current perspective on snake venom composition and constituent protein families. Arch Toxicol 2023; 97:133-153. [PMID: 36437303 DOI: 10.1007/s00204-022-03420-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 11/09/2022] [Indexed: 11/28/2022]
Abstract
Snake venoms are heterogeneous mixtures of proteins and peptides used for prey subjugation. With modern proteomics there has been a rapid expansion in our knowledge of snake venom composition, resulting in the venom proteomes of 30% of vipers and 17% of elapids being characterised. From the reasonably complete proteomic coverage of front-fanged snake venom composition (179 species-68 species of elapids and 111 species of vipers), the venoms of vipers and elapids contained 42 different protein families, although 18 were only reported in < 5% of snake species. Based on the mean abundance and occurrence of the 42 protein families, they can be classified into 4 dominant, 6 secondary, 14 minor, and 18 rare protein families. The dominant, secondary and minor categories account for 96% on average of a snake's venom composition. The four dominant protein families are: phospholipase A2 (PLA2), snake venom metalloprotease (SVMP), three-finger toxins (3FTx), and snake venom serine protease (SVSP). The six secondary protein families are: L-amino acid oxidase (LAAO), cysteine-rich secretory protein (CRiSP), C-type lectins (CTL), disintegrins (DIS), kunitz peptides (KUN), and natriuretic peptides (NP). Venom variation occurs at all taxonomic levels, including within populations. The reasons for venom variation are complex, as variation is not always associated with geographical variation in diet. The four dominant protein families appear to be the most important toxin families in human envenomation, being responsible for coagulopathy, neurotoxicity, myotoxicity and cytotoxicity. Proteomic techniques can be used to investigate the toxicological profile of a snake venom and hence identify key protein families for antivenom immunorecognition.
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Estrada-Gómez S, Vargas-Muñoz LJ, Higuita-Gutiérrez LF. Epidemiology of Snake Bites Linked with the Antivenoms Production in Colombia 2008–2020: Produced Vials Do Not Meet the Needs. Drug Healthc Patient Saf 2022; 14:171-184. [PMID: 36199542 PMCID: PMC9528913 DOI: 10.2147/dhps.s367757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 08/13/2022] [Indexed: 11/23/2022] Open
Abstract
Introduction Snakebite envenomation is a public health event of mandatory reporting in Colombia. It is considered a medical emergency in which the government must guarantee antivenom availability. We describe snakebite epidemiological figures in Colombia between 2008 and 2020 and correlate them with antivenom manufacturing figures to determine rate coverage and the need for antivenom. Methods We performed an ecological study based on secondary official figures from the National Health Institute, the National Institute for Surveillance of Medicines and Foods, the National Administrative Department of Statistics and the Ministry of Health and Social Protection. Absolute and relative frequencies were calculated with 95% confidence intervals, position measurements, dispersion and central tendency. Results Through our research, we revealed that in the last 13 years (2008–2020), there were an average of 4467 annual snakebite envenomation cases affecting all the departments in Colombia. Antioquia reported the highest number of snakebites with 647 (95% CI 588–706) cases per year. The population incidence per 100,000 inhabitants was 9.5; the highest rates were found in Vaupés at 116.1 and Guaviare at 79.24. During the last seven years (2014–2020) Colombia produced an average of 21,104 antivenom vials per year, while the annual demand for antivenom is estimated at 54,440 units needed to guarantee access. Discussion Colombia does not produce sufficient vials to cover their needs, and this is why only 74.4% of accidents (out of the 92% not classified as dry bites) were treated, and even 9.7% of the severe accidents did not receive the specific treatment (8% of the victims were classified as dry bites). Figures support the regular antivenom shortages declared by the Ministry of Health and Social Protection in the last 13 years (11 health emergency declarations). New efforts are needed to: 1) boost the production of GMP-based high-quality antivenom, that covers the national needs and is made availability, 2) a better estimation method to calculate the need for antivenom in Colombia, and 3) implementation of production-distribution chains guaranteeing access in remote communities.
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Affiliation(s)
- Sebastián Estrada-Gómez
- Grupo de Toxinologia y Alternativas Terapeuticas Alimentarias, Universidad de Antioquia UdeA, Medellin, Antioquia, Colombia
- Tech Life Saving (TLS), Medellin, Antioquia, Colombia
- Centro de Investigación en Recursos Naturales y Sustentabilidad, Universidad Bernardo O’Higgins, Santiago de Chile, Chile
- Correspondence: Sebastián Estrada-Gómez, Email ;
| | - Leidy Johana Vargas-Muñoz
- Tech Life Saving (TLS), Medellin, Antioquia, Colombia
- Facultad de Medicina, Universidad Cooperativa de Colombia, Medellin, Antioquia, Colombia
| | - Luis Felipe Higuita-Gutiérrez
- Facultad de Medicina, Universidad Cooperativa de Colombia, Medellin, Antioquia, Colombia
- Escuela de Microbiología, Universidad de Antioquia UdeA, Medellin, Antioquia, Colombia
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12
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Isbister GK, Noutsos T, Jenkins S, Isoardi KZ, Soderstrom J, Buckley NA. D‐dimer testing for early detection of venom‐induced consumption coagulopathy after snakebite in Australia (
ASP
‐29). Med J Aust 2022; 217:203-207. [PMID: 35670073 PMCID: PMC9541317 DOI: 10.5694/mja2.51589] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 03/04/2022] [Accepted: 03/16/2022] [Indexed: 12/03/2022]
Abstract
Objective To assess the accuracy and marginal value of quantitative D‐dimer testing for diagnosing venom‐induced consumption coagulopathy (VICC) in people bitten by Australian snakes. Design, setting Analysis of data for suspected and confirmed cases of snakebite collected prospectively by the Australian Snakebite Project, 2005–2019, from 200 hospitals across Australia. Participants 1363 patients for whom D‐dimer was quantitatively assessed within 24 hours of suspected or confirmed snakebite. Main outcome measures Diagnostic performance of quantitative D‐dimer testing for detecting systemic envenoming with VICC (area under the receiver operating characteristic curve, AUC); optimal D‐dimer cut‐off value (maximum sum of sensitivity and specificity). Results D‐dimer values exceeded 2.5 mg/L within three hours of the bite for 95% of patients who developed VICC, and were lower than 2.5 mg/L for 95% of non‐envenomed patients up to six hours after snakebite. The AUC for diagnosing envenoming with VICC on the basis of quantitative D‐dimer testing within six hours of snakebite was 0.97 (95% CI, 0.96–0.98; 944 patients). Diagnostic performance increased during the first three hours after snakebite; for quantitative D‐dimer testing at 2–6 hours, the AUC was 0.99 (95% CI, 0.99–1.0); with a cut‐off of 2.5 mg/L, sensitivity was 97.1% (95% CI, 95.0–98.3%) and specificity 99.0% (95% CI, 97.6–99.6%) for VICC. For 36 patients with normal international normalised ratio (INR) and activated partial thromboplastin time (aPTT) values 2–6 hours after snakebite, the AUC was 0.97 (95% CI, 0.93–1.0); with a cut‐off of 1.4 mg/L, sensitivity was 94% (95% CI, 82–99%) and specificity 96% (95% CI, 94–97%). In all but one of 84 patients who developed VICC‐related acute kidney injury, D‐dimer values exceeded 4 mg/L within 24 hours of the bite. Conclusion D‐dimer concentrations assessed 2–6 hours after snakebite, with a cut‐off value of 2.5 mg/L, could be useful for diagnosing envenoming with VICC.
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Affiliation(s)
- Geoffrey K Isbister
- The University of Newcastle Newcastle NSW
- Calvary Mater Newcastle Newcastle NSW
| | | | | | - Katherine Z Isoardi
- Princess Alexandra Hospital Brisbane QLD
- Queensland Poisons Information Centre Queensland Children’s Hospital Brisbane QLD
| | - Jessamine Soderstrom
- Royal Perth Hospital Perth WA
- Western Australia Poisons Information Centre Sir Charles Gairdner Hospital Perth WA
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13
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Cavalcante JDS, de Almeida CAS, Clasen MA, da Silva EL, de Barros LC, Marinho AD, Rossini BC, Marino CL, Carvalho PC, Jorge RJB, Dos Santos LD. A fingerprint of plasma proteome alteration after local tissue damage induced by Bothrops leucurus snake venom in mice. J Proteomics 2022; 253:104464. [PMID: 34954398 DOI: 10.1016/j.jprot.2021.104464] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 11/30/2021] [Accepted: 12/19/2021] [Indexed: 12/21/2022]
Abstract
Bothrops spp. is responsible for about 70% of snakebites in Brazil, causing a diverse and complex pathophysiological condition. Bothrops leucurus is the main species of medical relevance found in the Atlantic coast in the Brazilian Northeast region. The pathophysiological effects involved B. leucurus snakebite as well as the organism's reaction in response to this envenoming, it has not been explored yet. Thus, edema was induced in mice paw using 1.2, 2.5, and 5.0 μg of B. leucurus venom, the percentage of edema was measured 30 min after injection and the blood plasma was collected and analyzed by shotgun proteomic strategy. We identified 80 common plasma proteins with differential abundance among the experimental groups and we can understand the early aspects of this snake envenomation, regardless of the suggestive severity of an ophidian accident. The results showed B. leucurus venom triggers a thromboinflammation scenario where family's proteins of the Serpins, Apolipoproteins, Complement factors and Component subunits, Cathepsins, Kinases, Oxidoreductases, Proteases inhibitors, Proteases, Collagens, Growth factors are related to inflammation, complement and coagulation systems, modulators platelets and neutrophils, lipid and retinoid metabolism, oxidative stress and tissue repair. Our findings set precedents for future studies in the area of early diagnosis and/or treatment of snakebites. SIGNIFICANCE: The physiopathological effects that the snake venoms can cause have been investigated through classical and reductionist tools, which allowed, so far, the identification of action mechanisms of individual components associated with specific tissue damage. The currently incomplete limitations of this knowledge must be expanded through new approaches, such as proteomics, which may represent a big leap in understanding the venom-modulated pathological process. The exploration of the complete protein set that suffer modifications by the simultaneous action of multiple toxins, provides a map of the establishment of physiopathological phenotypes, which favors the identification of multiple toxin targets, that may or may not act in synergy, as well as favoring the discovery of biomarkers and therapeutic targets for manifestations that are not neutralized by the antivenom.
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Affiliation(s)
- Joeliton Dos Santos Cavalcante
- Graduate Program in Tropical Diseases, Botucatu Medical School (FMB), São Paulo State University (UNESP), Botucatu, SP, Brazil
| | | | - Milan Avila Clasen
- Laboratory for Structural and Computational Proteomics, ICC, Oswaldo Cruz Foundation (FIOCRUZ), Curitiba, PR, Brazil
| | - Emerson Lucena da Silva
- Drug Research and Development Center, Federal University of Ceará (UFC), Fortaleza, CE, Brazil; Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceará (UFC), Fortaleza, CE, Brazil
| | - Luciana Curtolo de Barros
- Center for the Study of Venoms and Venomous Animals (CEVAP), São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Aline Diogo Marinho
- Drug Research and Development Center, Federal University of Ceará (UFC), Fortaleza, CE, Brazil; Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceará (UFC), Fortaleza, CE, Brazil
| | - Bruno Cesar Rossini
- Biotechnology Institute (IBTEC), São Paulo State University (UNESP), Botucatu, SP, Brazil; Department of Chemical and Biological Sciences, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Celso Luís Marino
- Biotechnology Institute (IBTEC), São Paulo State University (UNESP), Botucatu, SP, Brazil; Department of Chemical and Biological Sciences, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Paulo Costa Carvalho
- Laboratory for Structural and Computational Proteomics, ICC, Oswaldo Cruz Foundation (FIOCRUZ), Curitiba, PR, Brazil
| | - Roberta Jeane Bezerra Jorge
- Drug Research and Development Center, Federal University of Ceará (UFC), Fortaleza, CE, Brazil; Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceará (UFC), Fortaleza, CE, Brazil
| | - Lucilene Delazari Dos Santos
- Graduate Program in Tropical Diseases, Botucatu Medical School (FMB), São Paulo State University (UNESP), Botucatu, SP, Brazil; Biotechnology Institute (IBTEC), São Paulo State University (UNESP), Botucatu, SP, Brazil.
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14
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Investigating myotoxicity following Australian red-bellied black snake (Pseudechis porphyriacus) envenomation. PLoS One 2021; 16:e0256653. [PMID: 34506531 PMCID: PMC8432874 DOI: 10.1371/journal.pone.0256653] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 08/11/2021] [Indexed: 11/19/2022] Open
Abstract
Background Myotoxicity is one of the common clinical manifestations of red-bellied black snake (Pseudechis porphyriacus) envenomation characterised by elevated creatine kinase (CK) concentrations of greater than 1000 U/L. This study aimed to investigate the occurrence of myotoxicity in patients following envenomation. Methods/Principal findings Patient characteristics and serial blood samples (timed venom concentrations and CK concentrations, pre- and post- antivenom) from 114 patients (median age 41, 2-90y; 80 male) were extracted from the Australian Snakebite Project database. Patients were categorised into three groups based on peak CK concentrations [no myotoxicity (<1000 U/L), mild (1000–10,000 U/L) and severe (>10,000 U/L)]. The odds of (mild or severe) myotoxicity was lower in patients that received early antivenom (within 6 hours post-bite) compared to those that received late or no antivenom (odd ratio was 0.186; 95% confidence interval, 0.052–0.664). A population pharmacokinetic-pharmacodynamic (PKPD) model was developed to describe the relationship between the time course of venom (a mixture of toxins) and effect (elevated CK). In addition, a kinetic-pharmacodynamic (KPD) model was developed to describe the relationship between time course of a theoretical toxin and effect. Model development and parameter estimation was performed using NONMEM v7.3. No single set of parameter values from either the PKPD or KPD models were found that could accurately describe the time course of different levels of severity of myotoxicity. The predicted theoretical toxin half-life from the KPD model was 11 ± 3.9 hours compared to the half-life of venom of 5.3 ± 0.36 hours. This indicates that the putative causative toxin’s concentration-time profile does not parallel that of venom. Conclusion Early antivenom administration reduces the incidence of myotoxicity. The venom concentration profile does not appear to be the driver for myotoxicity following envenomation. Additional factors that affect the sensitivity of the patient to snake venom/toxins must be explored to understand the relationship with myotoxicity.
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15
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Hamza M, Knudsen C, Gnanathasan CA, Monteiro W, Lewin MR, Laustsen AH, Habib AG. Clinical management of snakebite envenoming: Future perspectives. Toxicon X 2021; 11:100079. [PMID: 34430847 PMCID: PMC8374517 DOI: 10.1016/j.toxcx.2021.100079] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 06/29/2021] [Accepted: 07/30/2021] [Indexed: 11/18/2022] Open
Abstract
Snakebite envenoming is a major cause of morbidity and mortality in rural communities throughout the tropics. Generally, the main clinical features of snakebites are local swelling, tissue necrosis, shock, spontaneous systemic hemorrhage, incoagulable blood, paralysis, rhabdomyolysis, and acute kidney injury. These clinical manifestations result from complex biochemical venom constituents comprising of cytotoxins, hemotoxins, neurotoxins, myotoxins, and other substances. Timely diagnosis of envenoming and identification of the responsible snake species is clinically challenging in many parts of the world and necessitates prompt and thorough clinical assessment, which could be supported by the development of reliable, affordable, widely-accessible, point-of-care tests. Conventional antivenoms based on polyclonal antibodies derived from animals remain the mainstay of therapy along with supportive medical and surgical care. However, while antivenoms save countless lives, they are associated with adverse reactions, limited potency, and are relatively inefficacious against presynaptic neurotoxicity and in preventing necrosis. Nevertheless, major scientific and technological advances are facilitating the development of new molecular and immunologic diagnostic tests, as well as a new generation of antivenoms comprising human monoclonal antibodies with broader and more potent neutralization capacity and less immunogenicity. Repurposed pharmaceuticals based on small molecule inhibitors (e.g., marimastat and varespladib) used alone and in combination against enzymatic toxins, such as metalloproteases and phospholipase A2s, have shown promise in animal studies. These orally bioavailable molecules could serve as early interventions in the out-of-hospital setting if confirmed to be safe and efficacious in clinical studies. Antivenom access can be improved by the usage of drones and ensuring constant antivenom supply in remote endemic rural areas. Overall, the improvement of clinical management of snakebite envenoming requires sustained, coordinated, and multifaceted efforts involving basic and applied sciences, new technology, product development, effective clinical training, implementation of existing guidelines and therapeutic approaches, supported by improved supply of existing antivenoms.
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Affiliation(s)
- Muhammad Hamza
- Infectious and Tropical Diseases Unit, Bayero University Kano, Nigeria
| | - Cecilie Knudsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | - Wuelton Monteiro
- Department of Research, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
- School of Health Sciences, Universidade do Estado do Amazonas, Manaus, Brazil
| | - Matthew R. Lewin
- Center for Exploration and Travel Health, California Academy of Sciences, San Francisco, USA
| | - Andreas H. Laustsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
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16
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The Snake Study: Survey of National Attitudes and Knowledge in Envenomation. Toxins (Basel) 2021; 13:toxins13070482. [PMID: 34357954 PMCID: PMC8310140 DOI: 10.3390/toxins13070482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 07/09/2021] [Accepted: 07/10/2021] [Indexed: 11/27/2022] Open
Abstract
Despite recent reviews of best practice for the treatment of Australian venomous bites and stings, there is controversy about some aspects of care, particularly the use of antivenom. Our aim was to understand current attitudes and practice in the management of suspected snake envenoming. A single-stage, cross-sectional survey of Australian emergency care physicians who had treated snake envenomation in the previous 36 months was conducted. Hospital pharmacists were also invited to complete a survey about antivenom availability, usage, and wastage in Australian hospitals. The survey was available between 5 March and 16 June 2019. A total of 121 snake envenoming cases were reported, and more than a third (44.6%) of patients were not treated with antivenom. For those treated with antivenom (n = 67), 29 patients (43%) received more than one ampoule. Nearly a quarter of respondents (21%) identified that antivenom availability was, or could be, a barrier to manage snake envenoming, while cost was identified as the least important factor. Adverse reactions following antivenom use were described in 11.9% of cases (n = 8). The majority of patients with suspected envenoming did not receive antivenom. We noted variation in dosage, sources of information, beliefs, and approaches to the care of the envenomed patient.
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17
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Knudsen C, Jürgensen JA, Føns S, Haack AM, Friis RUW, Dam SH, Bush SP, White J, Laustsen AH. Snakebite Envenoming Diagnosis and Diagnostics. Front Immunol 2021; 12:661457. [PMID: 33995385 PMCID: PMC8113877 DOI: 10.3389/fimmu.2021.661457] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 03/29/2021] [Indexed: 11/13/2022] Open
Abstract
Snakebite envenoming is predominantly an occupational disease of the rural tropics, causing death or permanent disability to hundreds of thousands of victims annually. The diagnosis of snakebite envenoming is commonly based on a combination of patient history and a syndromic approach. However, the availability of auxiliary diagnostic tests at the disposal of the clinicians vary from country to country, and the level of experience within snakebite diagnosis and intervention may be quite different for clinicians from different hospitals. As such, achieving timely diagnosis, and thus treatment, is a challenge faced by treating personnel around the globe. For years, much effort has gone into developing novel diagnostics to support diagnosis of snakebite victims, especially in rural areas of the tropics. Gaining access to affordable and rapid diagnostics could potentially facilitate more favorable patient outcomes due to early and appropriate treatment. This review aims to highlight regional differences in epidemiology and clinical snakebite management on a global scale, including an overview of the past and ongoing research efforts within snakebite diagnostics. Finally, the review is rounded off with a discussion on design considerations and potential benefits of novel snakebite diagnostics.
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Affiliation(s)
- Cecilie Knudsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
- BioPorto Diagnostics A/S, Hellerup, Denmark
| | - Jonas A. Jürgensen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Sofie Føns
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Aleksander M. Haack
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Rasmus U. W. Friis
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Søren H. Dam
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Sean P. Bush
- Department of Emergency Medicine, Yale School of Medicine, New Haven, CT, United States
| | - Julian White
- Toxinology Department, Women’s and Children’s Hospital, North Adelaide, SA, Australia
| | - Andreas H. Laustsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
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Liblik K, Byun J, Saldarriaga C, Perez GE, Lopez-Santi R, Wyss FQ, Liprandi AS, Martinez-Sellés M, Farina JM, Mendoza I, Burgos LM, Baranchuk A. Snakebite Envenomation and Heart: Systematic Review. Curr Probl Cardiol 2021; 47:100861. [PMID: 33992425 DOI: 10.1016/j.cpcardiol.2021.100861] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 03/27/2021] [Indexed: 12/15/2022]
Abstract
Snakebite envenomation is a neglected tropical disease which can result in morbidity and mortality. Cardiac implications are poorly understood due to the low frequency of cardiotoxicity combined with a lack of robust information, as snakebites commonly occur in remote and rural areas. This review aims to assess cardiovascular implications of snakebite envenoming and proposes an algorithm for screening of cardiovascular manifestations. A systematic review was performed and 29 articles relating to cardiovascular involvement in snakebite envenomation were selected. Cardiovascular involvement seems to be rare and includes a wide spectrum of outcomes, such as myocardial infarction, ventricular dysfunction, hypotension, cardiac arrest, and myocarditis. In a significant proportion of the cases analyzed (24.39%), the cardiovascular manifestations had major consequences (cardiac arrest, myocardial infarction, malignant ventricular arrhythmias, or death). Clinical monitoring, physical examination, and early electrocardiogram should be considered as key measures to detect cardiovascular involvement in patients with evidence of systemic illness.
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Affiliation(s)
- Kiera Liblik
- Department of Medicine, Kingston Health Science Center, Queen's University, Kingston, Ontario, Canada
| | - Jin Byun
- Faculty of Health Sciences, Queen's University, Kingston, Ontario, Canada
| | - Clara Saldarriaga
- Department of Cardiology and Heart Failure Clinic, Cardiovascular Clinic Santa Maria, University of Antioquia, Medellín, Colombia
| | - Gonzalo E Perez
- Division of Cardiology, Clínica Olivos, Buenos Aires, Argentina
| | - Ricardo Lopez-Santi
- Division of Cardiology, Hospital Italiano de la Plata, Buenos Aires, Argentina
| | - Fernando Q Wyss
- Division of Cardiology, Clínica Olivos, Buenos Aires, Argentina
| | - Alvaro S Liprandi
- Guatemala Cardiovascular Services and Technology, Cardiosolutions, Guatemala City
| | | | - Juan M Farina
- Hospital General Universitario Gregorio Marañón, CIBERCV, Universidad Europea, Universidad Complutense, Madrid, Spain
| | - Ivan Mendoza
- Tropical Cardiology, Tropical Medicine Institute, Central University of Venezuela, Caracas, Venezuela
| | - Lucrecia M Burgos
- Department of Heart Failure, Pulmonary Hypertension and Heart Transplant, Instituto Cardiovascular de Buenos Aires, Buenos Aires, Argentina
| | - Adrian Baranchuk
- Division of Cardiology, Kingston Health Science Center, Queen's University, Kingston, Ontario, Canada.
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Noutsos T, Currie BJ, Lek RA, Isbister GK. Snakebite associated thrombotic microangiopathy: a systematic review of clinical features, outcomes, and evidence for interventions including plasmapheresis. PLoS Negl Trop Dis 2020; 14:e0008936. [PMID: 33290400 PMCID: PMC7748274 DOI: 10.1371/journal.pntd.0008936] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 12/18/2020] [Accepted: 10/30/2020] [Indexed: 02/06/2023] Open
Abstract
Snakebite is a neglected tropical disease with significant morbidity and mortality. Thrombotic microangiopathy (TMA) is an important but poorly understood complication of snakebite associated with acute kidney injury (AKI). Numerous treatments have been attempted based on limited evidence. We conducted a systematic review of TMA following snakebite using a pre-determined case definition of blood film red cell schistocytes or histologically diagnosed TMA. The search strategy included major electronic databases and grey literature. We present a descriptive synthesis for the outcomes of AKI, dialysis free survival (DFS), other end-organ damage, overall survival, and interventions with antivenom and therapeutic plasmapheresis (TPE). This study was prospectively registered with PROSPERO (CRD42019121436). Seventy-two studies reporting 351 cases were included, predominantly small observational studies. Heterogeneity for study selection, design, reporting and outcomes were observed. The commonest envenoming species were hump-nosed vipers (Hypnale spp.), Russell's viper (Daboia russelii) and Australian brown snakes (Pseudechis spp.). The prevalence of TMA was at least 5.4% in proven and probable Hypnale bites, and 10-15% of Australian elapid envenomings, AKI occurred in 94% (293/312) of TMA cases, excluding case reports. The majority of cases with AKI required dialysis. Included prospective and retrospective cohort studies reporting interventions and renal outcomes showed no evidence for benefit from antivenom or TPE with respect to DFS in dialysis dependant AKI. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) assessment for quality of accumulated evidence for interventions was low. The major complication of TMA following snakebite is AKI. AKI improves in most cases. We found no evidence to support benefit from antivenom in snakebite associated TMA, but antivenom remains the standard of care for snake envenoming. There was no evidence for benefit of TPE in snakebite associated TMA, so TPE cannot be recommended. The quality of accumulated evidence was low, highlighting a need for high quality larger studies.
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Affiliation(s)
- Tina Noutsos
- Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
- Flinders Health and Medical Research Institute, Flinders University, Australia
- Division of Medicine, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - Bart J. Currie
- Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
- Division of Medicine, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - Rachel A. Lek
- Flinders Health and Medical Research Institute, Flinders University, Australia
| | - Geoffrey K. Isbister
- Clinical Toxicology Research Group, University of Newcastle, Newcastle, New South Wales, Australia
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20
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Silva A, Hlusicka J, Siribaddana N, Waiddyanatha S, Pilapitiya S, Weerawansa P, Lokunarangoda N, Thalgaspitiya S, Siribaddana S, Isbister GK. Time delays in treatment of snakebite patients in rural Sri Lanka and the need for rapid diagnostic tests. PLoS Negl Trop Dis 2020; 14:e0008914. [PMID: 33253208 PMCID: PMC7728389 DOI: 10.1371/journal.pntd.0008914] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 12/10/2020] [Accepted: 10/23/2020] [Indexed: 02/07/2023] Open
Abstract
Delays in treatment seeking and antivenom administration remain problematic for snake envenoming. We aimed to describe the treatment seeking pattern and delays in admission to hospital and administration of antivenom in a cohort of authenticated snakebite patients. Adults (> 16 years), who presented with a confirmed snakebite from August 2013 to October 2014 were recruited from Anuradhapura Hospital. Demographic data, information on the circumstances of the bite, first aid, health-seeking behaviour, hospital admission, clinical features, outcomes and antivenom treatment were documented prospectively. There were 742 snakebite patients [median age: 40 years (IQR:27–51; males: 476 (64%)]. One hundred and five (14%) patients intentionally delayed treatment by a median of 45min (IQR:20-120min). Antivenom was administered a median of 230min (IQR:180–360min) post-bite, which didn’t differ between directly admitted and transferred patients; 21 (8%) receiving antivenom within 2h and 141 (55%) within 4h of the bite. However, transferred patients received antivenom sooner after admission to Anuradhapura hospital than those directly admitted (60min [IQR:30-120min] versus 120min [IQR:52-265min; p<0.0001]). A significantly greater proportion of transferred patients had features of systemic envenoming on admission compared to those directly admitted (166/212 [78%] versus 5/43 [12%]; p<0.0001), and had positive clotting tests on admission (123/212 [58%] versus 10/43 [23%]; p<0.0001). Sri Lankan snakebite patients present early to hospital, but there remains a delay until antivenom administration. This delay reflects a delay in the appearance of observable or measurable features of envenoming and a lack of reliable early diagnostic tests. Improved early antivenom treatment will require reliable, rapid diagnostics for systemic envenoming. Snakebite is a neglected tropical disease which is closely associated with underdevelopment. Poor accessibility to safe and effective antivenoms is a major issue in some regions highest-affected by snakebites. Antivenom can prevent severe effects of envenoming if given early. Therefore, educating communities and health care workers to improve treatment seeking after snakebite is a global priority. Many factors are associated with delayed presentation to hospital and early administration of antivenom. We found that most snakebite patients in Sri Lanka present to the first hospital within an hour of the bite. However, there remains a delay of about two more hours until the first dose of antivenom is administered. This delay is a reflection of a delay in the appearance of observable or measurable features of envenoming and a lack of reliable early diagnostic tests. We emphasise the need for reliable, rapid diagnostics for systemic envenoming.
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Affiliation(s)
- Anjana Silva
- Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka
- Monash Venom Group, Faculty of Medicine, Nursing and Health Sciences, Monash University, Australia
- South Asian Clinical Toxicology Research Collaboration, University of Peradeniya, Peradeniya, Sri Lanka
- * E-mail:
| | - Jiri Hlusicka
- Charles University in Prague, 1st Faculty of Medicine, 4th Department of Internal Medicine, Prague, Czech Republic
| | - Nipuna Siribaddana
- Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka
| | - Subodha Waiddyanatha
- Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka
- South Asian Clinical Toxicology Research Collaboration, University of Peradeniya, Peradeniya, Sri Lanka
| | - Senaka Pilapitiya
- Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka
| | - Prasanna Weerawansa
- Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka
| | - Niroshan Lokunarangoda
- Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka
| | - Sujeewa Thalgaspitiya
- Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka
| | - Sisira Siribaddana
- Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka
| | - Geoffrey K. Isbister
- Monash Venom Group, Faculty of Medicine, Nursing and Health Sciences, Monash University, Australia
- South Asian Clinical Toxicology Research Collaboration, University of Peradeniya, Peradeniya, Sri Lanka
- Clinical Toxicology Research Group, School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales, Australia
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Abstract
BACKGROUND Myotoxicity is a recognised but poorly characterised effect of snake envenoming worldwide. We aimed to describe the clinical effects, complications and effectiveness of antivenom in myotoxicity from Australian snake envenoming. METHODS Patients were recruited to the Australian Snakebite Project (ASP), a prospective, observational study of patients with suspected or proven snakebite countrywide. After informed consent data is collected and stored in a dedicated database and blood samples are taken and stored. We included patients with envenoming and biochemical evidence of myotoxicity (peak creatine kinase [CK] > 1000 U/L). Snake species was determined by expert identification or venom specific enzyme immunoassay. Analysis included patient demographics, clinical findings, pathology results, treatment and outcomes (length of hospital stay, complications). RESULTS 1638 patients were recruited January 2003-December 2016, 935 (57%) were envenomed, 148 developed myotoxicity (16%). Snake species most commonly associated with myotoxicity were Notechis spp. (30%), Pseudechis porphyriacus (20%) and Pseudechis australis (13%). Bite site effects occurred in 19 patients. Non-specific systemic symptoms occurred in 135 patients (91%), specific signs and symptoms in 83. In 120 patients with early serial CK results, the median peak CK was 3323 U/L (IQR;1050-785100U/L), the median time to first CK >500 U/L was 11.1 h and median time to peak CK of 34.3 h. White cell count was elevated in 136 patients (93%; median time to elevation, 4.9 h). 37 patients had elevated creatinine, six were dialysed. Two patients died from complications of severe myotoxicity. Antivenom given before the first abnormal CK (>500 U/L) was associated with less severe myotoxicity (2976 versus 7590 U/L). Non-envenomed patients with elevated CK had rapid rise to abnormal CK (median 3.5 h) and less had elevated WCC (32%). CONCLUSION Myotoxicity from Australian snakes is relatively common and has systemic effects, with significant associated morbidity and mortality. CK is not a good early biomarker of mytoxicity. Early antivenom may play a role in reducing severity.
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Madhushani U, Isbister GK, Tasoulis T, Hodgson WC, Silva A. In-Vitro Neutralization of the Neurotoxicity of Coastal Taipan Venom by Australian Polyvalent Antivenom: The Window of Opportunity. Toxins (Basel) 2020; 12:toxins12110690. [PMID: 33142783 PMCID: PMC7694127 DOI: 10.3390/toxins12110690] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 10/27/2020] [Accepted: 10/30/2020] [Indexed: 12/17/2022] Open
Abstract
Coastal taipan (Oxyuranus scutellatus) envenoming causes life-threatening neuromuscular paralysis in humans. We studied the time period during which antivenom remains effective in preventing and arresting in vitro neuromuscular block caused by taipan venom and taipoxin. Venom showed predominant pre-synaptic neurotoxicity at 3 µg/mL and post-synaptic neurotoxicity at 10 µg/mL. Pre-synaptic neurotoxicity was prevented by addition of Australian polyvalent antivenom before the venom and taipoxin and, reversed when antivenom was added 5 min after venom and taipoxin. Antivenom only partially reversed the neurotoxicity when added 15 min after venom and had no significant effect when added 30 min after venom. In contrast, post-synaptic activity was fully reversed when antivenom was added 30 min after venom. The effect of antivenom on pre-synaptic neuromuscular block was reproduced by washing the bath at similar time intervals for 3 µg/mL, but not for 10 µg/mL. We found an approximate 10–15 min time window in which antivenom can prevent pre-synaptic neuromuscular block. This time window is likely to be longer in envenomed patients due to the delay in venom absorption. Similar effectiveness of antivenom and washing with 3 µg/mL venom suggests that antivenom most likely acts by neutralizing pre-synaptic toxins before they interfere with neurotransmission inside the motor nerve terminals.
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Affiliation(s)
- Umesha Madhushani
- Department of Parasitology, Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Mihintale 50300, Sri Lanka;
| | - Geoffrey K. Isbister
- Clinical Toxicology Research Group, University of Newcastle, Callaghan 2308, Australia; (G.K.I.); (T.T.)
| | - Theo Tasoulis
- Clinical Toxicology Research Group, University of Newcastle, Callaghan 2308, Australia; (G.K.I.); (T.T.)
| | - Wayne C. Hodgson
- Monash Venom Group, Department of Pharmacology, Biomedical Discovery Institute, Monash University, Clayton 3800, Australia;
| | - Anjana Silva
- Department of Parasitology, Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Mihintale 50300, Sri Lanka;
- Monash Venom Group, Department of Pharmacology, Biomedical Discovery Institute, Monash University, Clayton 3800, Australia;
- Correspondence:
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Isbister GK, Mirajkar N, Fakes K, Brown SGA, Veerati PC. Phospholipase A2 (PLA 2) as an Early Indicator of Envenomation in Australian Elapid Snakebites (ASP-27). Biomedicines 2020; 8:biomedicines8110459. [PMID: 33138056 PMCID: PMC7692658 DOI: 10.3390/biomedicines8110459] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 10/27/2020] [Accepted: 10/27/2020] [Indexed: 01/28/2023] Open
Abstract
Early diagnosis of snake envenomation is essential, especially neurotoxicity and myotoxicity. We investigated the diagnostic value of serum phospholipase (PLA2) in Australian snakebites. In total, 115 envenomated and 80 non-envenomated patients were recruited over 2 years, in which an early blood sample was available pre-antivenom. Serum samples were analyzed for secretory PLA2 activity using a Cayman sPLA2 assay kit (#765001 Cayman Chemical Company, Ann Arbor MI, USA). Venom concentrations were measured for snake identification using venom-specific enzyme immunoassay. The most common snakes were Pseudonaja spp. (33), Notechis scutatus (24), Pseudechis porphyriacus (19) and Tropidechis carinatus (17). There was a significant difference in median PLA2 activity between non-envenomated (9 nmol/min/mL; IQR: 7–11) and envenomated patients (19 nmol/min/mL; IQR: 10–66, p < 0.0001) but Pseudonaja spp. were not different to non-envenomated. There was a significant correlation between venom concentrations and PLA2 activity (r = 0.71; p < 0.0001). PLA2 activity was predictive for envenomation; area under the receiver-operating-characteristic curve (AUC-ROC), 0.79 (95% confidence intervals [95%CI]: 0.72–0.85), which improved with brown snakes excluded, AUC-ROC, 0.88 (95%CI: 0.82–0.94). A cut-point of 16 nmol/min/mL gives a sensitivity of 72% and specificity of 100% for Australian snakes, excluding Pseudonaja. PLA2 activity was a good early predictor of envenomation in most Australian elapid bites. A bedside PLA2 activity test has potential utility for early case identification but may not be useful for excluding envenomation.
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Affiliation(s)
- Geoffrey K. Isbister
- Clinical Toxicology Research Group, University of Newcastle, Newcastle, NSW 2298, Australia; (N.M.); (K.F.); (P.C.V.)
- Correspondence: ; Tel.: +61-249211211
| | - Nandita Mirajkar
- Clinical Toxicology Research Group, University of Newcastle, Newcastle, NSW 2298, Australia; (N.M.); (K.F.); (P.C.V.)
| | - Kellie Fakes
- Clinical Toxicology Research Group, University of Newcastle, Newcastle, NSW 2298, Australia; (N.M.); (K.F.); (P.C.V.)
| | - Simon G. A. Brown
- Aeromedical and Retrieval Medicine, Ambulance Tasmania, Hobart, TAS 7001, Australia;
| | - Punnam Chander Veerati
- Clinical Toxicology Research Group, University of Newcastle, Newcastle, NSW 2298, Australia; (N.M.); (K.F.); (P.C.V.)
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Tasoulis T, Silva A, Veerati PC, Baker M, Hodgson WC, Dunstan N, Isbister GK. Intra-Specific Venom Variation in the Australian Coastal Taipan Oxyuranus scutellatus. Toxins (Basel) 2020; 12:toxins12080485. [PMID: 32751571 PMCID: PMC7472000 DOI: 10.3390/toxins12080485] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 07/13/2020] [Accepted: 07/27/2020] [Indexed: 12/18/2022] Open
Abstract
Intra-specific venom variation has the potential to provide important insights into the evolution of snake venom, but remains a relatively neglected aspect of snake venom studies. We investigated the venom from 13 individual coastal taipans Oxyuranus scutellatus from four localities on the north-east coast of Australia, spanning a distance of 2000 km. The intra-specific variation in taipan venom was considerably less than the inter-specific variation between it and the other Australian elapids to which it was compared. The electrophoretic venom profile of O. scutellatus was visually different to six other genera of Australian elapids, but not to its congener inland taipan O. microlepidotus. There was minimal geographical variation in taipan venom, as the intra-population variation exceeded the inter-population variation for enzymatic activity, procoagulant activity, and the abundance of neurotoxins. The pre-synaptic neurotoxin (taipoxin) was more abundant than the post-synaptic neurotoxins (3FTx), with a median of 11.0% (interquartile range (IQR): 9.7% to 18.3%; range: 6.7% to 23.6%) vs. a median of 3.4% (IQR: 0.4% to 6.7%; range: 0% to 8.1%). Three taipan individuals almost completely lacked post-synaptic neurotoxins, which was not associated with geography and occurred within two populations. We found no evidence of sexual dimorphism in taipan venom. Our study provides a basis for evaluating the significance of intra-specific venom variation within a phylogenetic context by comparing it to the inter-specific and inter-generic variation. The considerable intra-population variation we observed supports the use of several unpooled individuals from each population when making inter-specific comparisons.
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Affiliation(s)
- Theo Tasoulis
- Clinical Toxicology Research Group, University of Newcastle, Newcastle, NSW 2308, Australia; (P.C.V.); (G.K.I.)
- Correspondence:
| | - Anjana Silva
- Monash Venom Group, Monash University, Clayton, VIC 3800, Australia; (A.S.); (W.C.H.)
- Faculty of Medicine and Allied Sciences, Rajarata University, Anuradhapura-Rambewa Hwy, Anuradhapura 50008, Sri Lanka
| | - Punnam Chander Veerati
- Clinical Toxicology Research Group, University of Newcastle, Newcastle, NSW 2308, Australia; (P.C.V.); (G.K.I.)
| | - Mark Baker
- Priority Research Centre in Reproductive Biology, University of Newcastle, Newcastle, NSW 2308, Australia;
| | - Wayne C. Hodgson
- Monash Venom Group, Monash University, Clayton, VIC 3800, Australia; (A.S.); (W.C.H.)
| | | | - Geoffrey K. Isbister
- Clinical Toxicology Research Group, University of Newcastle, Newcastle, NSW 2308, Australia; (P.C.V.); (G.K.I.)
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25
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Isbister GK, Buckley NA. Risks and realities of single vial antivenom recommendations for envenoming by Australian elapid snakes. Med J Aust 2020; 213:45-45.e1. [DOI: 10.5694/mja2.50652] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Geoffrey K Isbister
- Clinical Toxicology Research GroupUniversity of Newcastle Newcastle NSW
- Calvary Mater Newcastle Newcastle NSW
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Van Der Meer E, Conway L, Little M, Hanson J. A case of acute hypogonadism following taipan (Oxyuranus scutellatus) envenomation. Toxicon 2020; 180:28-30. [PMID: 32289354 DOI: 10.1016/j.toxicon.2020.04.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 03/22/2020] [Accepted: 04/07/2020] [Indexed: 11/17/2022]
Abstract
A previously well man developed acute, marked tender bilateral gynaecomastia two months after confirmed taipan (Oxyuranus scutellatus) envenomation. He had had laboratory evidence of thrombotic microangiopathy (TMA) including microangiopathic haemolytic anaemia, thrombocytopenia and acute kidney injury. Scrotal ultrasound revealed bilateral testicular atrophy, his serum testosterone was repeatedly low, while his luteinising and follicle stimulating hormone were elevated. It is hypothesised that TMA-related testicular ischaemia was responsible for his primary gonadal failure and dramatic clinical presentation.
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Affiliation(s)
- Ebonney Van Der Meer
- Cooktown Multipurpose Health Service, 48 Hope St, Cooktown, Queensland, 4895, Australia.
| | - Luke Conway
- Cairns Hospital, 165 Esplanade, Cairns, Queensland, 4870, Australia.
| | - Mark Little
- Cairns Hospital, 165 Esplanade, Cairns, Queensland, 4870, Australia; NSW Poisons Information Centre, Hawkesbury Rd &, Hainsworth St, Westmead, NSW, 2145, Australia.
| | - Josh Hanson
- Cairns Hospital, 165 Esplanade, Cairns, Queensland, 4870, Australia; The Kirby Institute, Wallace Wurth Building, University of New South Wales, High St, Kensington, NSW, 2052, Australia.
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Knudsen C, Ledsgaard L, Dehli RI, Ahmadi S, Sørensen CV, Laustsen AH. Engineering and design considerations for next-generation snakebite antivenoms. Toxicon 2019; 167:67-75. [DOI: 10.1016/j.toxicon.2019.06.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 05/22/2019] [Accepted: 06/03/2019] [Indexed: 11/27/2022]
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Abstract
Long-term effects of envenoming compromise the quality of life of the survivors of snakebite. We searched MEDLINE (from 1946) and EMBASE (from 1947) until October 2018 for clinical literature on the long-term effects of snake envenoming using different combinations of search terms. We classified conditions that last or appear more than six weeks following envenoming as long term or delayed effects of envenoming. Of 257 records identified, 51 articles describe the long-term effects of snake envenoming and were reviewed. Disability due to amputations, deformities, contracture formation, and chronic ulceration, rarely with malignant change, have resulted from local necrosis due to bites mainly from African and Asian cobras, and Central and South American Pit-vipers. Progression of acute kidney injury into chronic renal failure in Russell's viper bites has been reported in several studies from India and Sri Lanka. Neuromuscular toxicity does not appear to result in long-term effects. Endocrine anomalies such as delayed manifestation of hypopituitarism following Russell's viper bites have been reported. Delayed psychological effects such as depressive symptoms, post-traumatic stress disorder and somatisation have been reported. Blindness due to primary and secondary effects of venom is a serious, debilitating effect. In general, the available studies have linked a clinical effect to a snakebite in retrospect, hence lacked accurate snake authentication, details of acute management and baseline data and are unable to provide a detailed picture of clinical epidemiology of the long-term effects of envenoming. In the future, it will be important to follow cohorts of snakebite patients for a longer period of time to understand the true prevalence, severity, clinical progression and risk factors of long-term effects of snake envenoming.
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Silva A, Cristofori-Armstrong B, Rash LD, Hodgson WC, Isbister GK. Defining the role of post-synaptic α-neurotoxins in paralysis due to snake envenoming in humans. Cell Mol Life Sci 2018; 75:4465-4478. [PMID: 30069700 PMCID: PMC11105319 DOI: 10.1007/s00018-018-2893-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 07/21/2018] [Accepted: 07/26/2018] [Indexed: 01/06/2023]
Abstract
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.
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Affiliation(s)
- Anjana Silva
- Monash Venom Group, Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
- Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, 50008, Sri Lanka
| | - Ben Cristofori-Armstrong
- School of Biomedical Sciences, University of Queensland, St. Lucia, QLD, 4072, Australia
- Institute of Molecular Bioscience, University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Lachlan D Rash
- School of Biomedical Sciences, University of Queensland, St. Lucia, QLD, 4072, Australia.
- Institute of Molecular Bioscience, University of Queensland, St. Lucia, QLD, 4072, Australia.
| | - Wayne C Hodgson
- Monash Venom Group, Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia.
| | - Geoffrey K Isbister
- Monash Venom Group, Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia.
- Clinical Toxicology Research Group, University of Newcastle, Callaghan, NSW, 2308, Australia.
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Fry BG. Snakebite: When the Human Touch Becomes a Bad Touch. Toxins (Basel) 2018; 10:E170. [PMID: 29690533 PMCID: PMC5923336 DOI: 10.3390/toxins10040170] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Revised: 04/19/2018] [Accepted: 04/20/2018] [Indexed: 01/08/2023] Open
Abstract
Many issues and complications in treating snakebite are a result of poor human social, economic and clinical intervention and management. As such, there is scope for significant improvements for reducing incidence and increasing patient outcomes. Snakes do not target humans as prey, but as our dwellings and farms expand ever farther and climate change increases snake activity periods, accidental encounters with snakes seeking water and prey increase drastically. Despite its long history, the snakebite crisis is neglected, ignored, underestimated and fundamentally misunderstood. Tens of thousands of lives are lost to snakebites each year and hundreds of thousands of people will survive with some form of permanent damage and reduced work capacity. These numbers are well recognized as being gross underestimations due to poor to non-existent record keeping in some of the most affected areas. These underestimations complicate achieving the proper recognition of snakebite’s socioeconomic impact and thus securing foreign aid to help alleviate this global crisis. Antivenoms are expensive and hospitals are few and far between, leaving people to seek help from traditional healers or use other forms of ineffective treatment. In some cases, cheaper, inappropriately manufactured antivenom from other regions is used despite no evidence for their efficacy, with often robust data demonstrating they are woefully ineffective in neutralizing many venoms for which they are marketed for. Inappropriate first-aid and treatments include cutting the wound, tourniquets, electrical shock, immersion in ice water, and use of ineffective herbal remedies by traditional healers. Even in the developed world, there are fundamental controversies including fasciotomy, pressure bandages, antivenom dosage, premedication such as adrenalin, and lack of antivenom for exotic snakebites in the pet trade. This review explores the myriad of human-origin factors that influence the trajectory of global snakebite causes and treatment failures and illustrate that snakebite is as much a sociological and economic problem as it is a medical one. Reducing the incidence and frequency of such controllable factors are therefore realistic targets to help alleviate the global snakebite burden as incremental improvements across several areas will have a strong cumulative effect.
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Affiliation(s)
- Bryan G Fry
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia, QLD 4072, Australia.
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Johnston CI, Ryan NM, Page CB, Buckley NA, Brown SG, O'Leary MA, Isbister GK. The Australian Snakebite Project, 2005-2015 (ASP-20). Med J Aust 2017; 207:119-125. [PMID: 28764620 DOI: 10.5694/mja17.00094] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 06/08/2017] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To describe the epidemiology, treatment and adverse events after snakebite in Australia. DESIGN Prospective, multicentre study of data on patients with snakebites recruited to the Australian Snakebite Project (2005-2015) and data from the National Coronial Information System. Setting, participants: Patients presenting to Australian hospitals with suspected or confirmed snakebites from July 2005 to June 2015 and consenting to participation. MAIN OUTCOME MEASURES Demographic data, circumstances of bites, clinical effects of envenoming, results of laboratory investigations and snake venom detection kit (SVDK) testing, antivenom treatment and adverse reactions, time to discharge, deaths. RESULTS 1548 patients with suspected snakebites were enrolled, including 835 envenomed patients (median, 87 per year), for 718 of which the snake type was definitively established, most frequently brown snakes (41%), tiger snakes (17%) and red-bellied black snakes (16%). Clinical effects included venom-induced consumption coagulopathy (73%), myotoxicity (17%), and acute kidney injury (12%); severe complications included cardiac arrest (25 cases; 2.9%) and major haemorrhage (13 cases; 1.6%). There were 23 deaths (median, two per year), attributed to brown (17), tiger (four) and unknown (two) snakes; ten followed out-of-hospital cardiac arrests and six followed intracranial haemorrhages. Of 597 SVDK test results for envenomed patients with confirmed snake type, 29 (4.9%) were incorrect; 133 of 364 SVDK test results for non-envenomed patients (36%) were false positives. 755 patients received antivenom, including 49 non-envenomed patients; 178 (24%), including ten non-envenomed patients, had systemic hypersensitivity reactions, of which 45 (6%) were severe (hypotension, hypoxaemia). Median total antivenom dose declined from four vials to one, but median time to first antivenom was unchanged (4.3 hours; IQR, 2.7-6.3 hours). CONCLUSIONS Snake envenoming is uncommon in Australia, but is often severe. SVDKs were unreliable for determining snake type. The median antivenom dose has declined without harming patients. Improved early diagnostic strategies are needed to reduce the frequently long delays before antivenom administration.
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Weinstein SA, Everest E, Purdell-Lewis J, Harrison M, Tavender F, Alfred S, Marrack L, Davenport-Klunder C, Wearn N, White J. Neurotoxicity with persistent unilateral ophthalmoplegia from envenoming by a wild inland taipan (Oxyuranus microlepidotus, Elapidae) in remote outback South Australia. Toxicon 2017; 137:15-18. [PMID: 28694006 DOI: 10.1016/j.toxicon.2017.07.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Revised: 07/03/2017] [Accepted: 07/05/2017] [Indexed: 11/26/2022]
Abstract
INTRODUCTION A case of life threatening envenoming by a wild specimen of the inland taipan, Oxyuranus microlepidotus, is described. There have been 11 previously well-documented envenomings by O. microlepidotus, but only 2 were inflicted by wild snakes. Envenomed patients have presented predominantly with defibrinating coagulopathy and neurotoxicity. CASE REPORT The victim was seeking to observe members of an isolated population of this species and was envenomed while attempting to photograph an approximately 1.5 m specimen. He reported feeling "drowsiness" and blurred vision that progressed to ptosis; he later developed dysphagia and dysarthria. The patient was treated with 1 vial of polyvalent antivenom, which was later followed with an additional two vials of taipan monovalent. He was intubated during retrieval, and recovered after 3 days of intensive care. He had a right ophthalmoplegia that persisted for approximately 1 week post-envenoming. Despite a positive 20-min whole blood clotting test, defibrination coagulopathy was absent, and there was no myotoxicity, or acute kidney injury. DISCUSSION Physicians presented with a patient envenomed by O. microlepidotus should remain cognizant of the possible variability of medically important venom toxins in some populations of this species. Some patients seriously envenomed by this species may develop persistent cranial nerve palsies. When clinically indicated, prompt provision of adequate antivenom is the cornerstone of managing O. microlepidotus envenoming. Rapid application of pressure-bandage immobilization and efficient retrieval of victims envenomed in remote locales, preferably by medically well-equipped aircraft, probably improves the likelihood of a positive outcome.
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Affiliation(s)
- Scott A Weinstein
- Toxinology Department, Women's and Children's Hospital, 72 King William Street, North Adelaide, South Australia, 5006, Australia; Department of Paediatrics and Reproductive Medicine, University of Adelaide School of Medicine, 30 Frome Street, Adelaide, South Australia, 5005, Australia.
| | - Evan Everest
- Intensive and Critical Care Unit, Flinders Medical Centre, Bedford Park, South Australia, 5042, Australia; MedSTAR Retrieval Service, South Australian Ambulance Service, 20 James Schofield Drive, Adelaide Airport, South Australia, 5950, Australia
| | - Jeremy Purdell-Lewis
- Royal Flying Doctor Service, Central Operations, 1 Tower Road, Adelaide Airport, South Australia, 5950, Australia
| | - Michael Harrison
- Royal Flying Doctor Service, Central Operations, 1 Tower Road, Adelaide Airport, South Australia, 5950, Australia
| | - Fiona Tavender
- MedSTAR Retrieval Service, South Australian Ambulance Service, 20 James Schofield Drive, Adelaide Airport, South Australia, 5950, Australia
| | - Sam Alfred
- Emergency Department, Royal Adelaide Hospital, North Terrace, Adelaide, 5000, Australia
| | - Liz Marrack
- Royal Flying Doctor Service, Central Operations, 1 Tower Road, Adelaide Airport, South Australia, 5950, Australia
| | - Chris Davenport-Klunder
- Royal Flying Doctor Service, Central Operations, 1 Tower Road, Adelaide Airport, South Australia, 5950, Australia
| | - Neralie Wearn
- MedSTAR Retrieval Service, South Australian Ambulance Service, 20 James Schofield Drive, Adelaide Airport, South Australia, 5950, Australia
| | - Julian White
- Toxinology Department, Women's and Children's Hospital, 72 King William Street, North Adelaide, South Australia, 5006, Australia; Department of Paediatrics and Reproductive Medicine, University of Adelaide School of Medicine, 30 Frome Street, Adelaide, South Australia, 5005, Australia
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Antivenom for Neuromuscular Paralysis Resulting From Snake Envenoming. Toxins (Basel) 2017; 9:toxins9040143. [PMID: 28422078 PMCID: PMC5408217 DOI: 10.3390/toxins9040143] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 04/11/2017] [Accepted: 04/13/2017] [Indexed: 02/06/2023] Open
Abstract
Antivenom therapy is currently the standard practice for treating neuromuscular dysfunction in snake envenoming. We reviewed the clinical and experimental evidence-base for the efficacy and effectiveness of antivenom in snakebite neurotoxicity. The main site of snake neurotoxins is the neuromuscular junction, and the majority are either: (1) pre-synaptic neurotoxins irreversibly damaging the presynaptic terminal; or (2) post-synaptic neurotoxins that bind to the nicotinic acetylcholine receptor. Pre-clinical tests of antivenom efficacy for neurotoxicity include rodent lethality tests, which are problematic, and in vitro pharmacological tests such as nerve-muscle preparation studies, that appear to provide more clinically meaningful information. We searched MEDLINE (from 1946) and EMBASE (from 1947) until March 2017 for clinical studies. The search yielded no randomised placebo-controlled trials of antivenom for neuromuscular dysfunction. There were several randomised and non-randomised comparative trials that compared two or more doses of the same or different antivenom, and numerous cohort studies and case reports. The majority of studies available had deficiencies including poor case definition, poor study design, small sample size or no objective measures of paralysis. A number of studies demonstrated the efficacy of antivenom in human envenoming by clearing circulating venom. Studies of snakes with primarily pre-synaptic neurotoxins, such as kraits (Bungarus spp.) and taipans (Oxyuranus spp.) suggest that antivenom does not reverse established neurotoxicity, but early administration may be associated with decreased severity or prevent neurotoxicity. Small studies of snakes with mainly post-synaptic neurotoxins, including some cobra species (Naja spp.), provide preliminary evidence that neurotoxicity may be reversed with antivenom, but placebo controlled studies with objective outcome measures are required to confirm this.
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A Pharmacological Examination of the Cardiovascular Effects of Malayan Krait (Bungarus candidus) Venoms. Toxins (Basel) 2017; 9:toxins9040122. [PMID: 28353659 PMCID: PMC5408196 DOI: 10.3390/toxins9040122] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 03/23/2017] [Accepted: 03/24/2017] [Indexed: 11/17/2022] Open
Abstract
Cardiovascular effects (e.g., tachycardia, hypo- and/or hypertension) are often clinical outcomes of snake envenoming. Malayan krait (Bungarus candidus) envenoming has been reported to cause cardiovascular effects that may be related to abnormalities in parasympathetic activity. However, the exact mechanism for this effect has yet to be determined. In the present study, we investigated the in vivo and in vitro cardiovascular effects of B. candidus venoms from Southern (BC-S) and Northeastern (BC-NE) Thailand. SDS-PAGE analysis of venoms showed some differences in the protein profile of the venoms. B. candidus venoms (50 µg/kg-100 µg/kg, i.v.) caused dose-dependent hypotension in anaesthetised rats. The highest dose caused sudden hypotension (phase I) followed by a return of mean arterial pressure to baseline levels and a decrease in heart rate with transient hypertension (phase II) prior to a small decrease in blood pressure (phase III). Prior administration of monovalent antivenom significantly attenuated the hypotension induced by venoms (100 µg/kg, i.v.). The sudden hypotensive effect of BC-NE venom was abolished by prior administration of hexamethonium (10 mg/kg, i.v.) or atropine (5 mg/kg, i.v.). BC-S and BC-NE venoms (0.1 µg/kg-100 µg/ml) induced concentration-dependent relaxation (EC50 = 8 ± 1 and 13 ± 3 µg/mL, respectively) in endothelium-intact aorta. The concentration-response curves were markedly shifted to the right by pre-incubation with L-NAME (0.2 mM), or removal of the endothelium, suggesting that endothelium-derived nitric oxide (NO) is likely to be responsible for venom-induced aortic relaxation. Our data indicate that the cardiovascular effects caused by B. candidus venoms may be due to a combination of vascular mediators (i.e., NO) and autonomic adaptation via nicotinic and muscarinic acetylcholine receptors.
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