Front Cover
“Venomous” Bites from “Non-Venomous” Snakes
“Venomous” Bites from “Non-Venomous” Snakes
Copyright
Dedication
Contents
About the authors
SCOTT A. WEINSTEIN, BA, MSC, PHD, MBBS, MD, DIP, ABFM, FAAFP
DAVID A. WARRELL, MA, DM, DSC, FRCP, FRCPE, HONFZS, FMEDSCI
DANIEL E. KEYLER, BS, BS PHARMACY, PHARMD, FAACT
Foreword
Preface to the second edition
Acknowledgments for the second edition
Introduction
1 - A summary of taxing taxonomic considerations: non-front-fanged snakes and the shifting sands of systematics
1.1 The shifting sands of taxonomic reassignments and their relevance to the envenomed patient
1.2 Brief glimpses of a vast landscape: the basics of taxonomic reassignments and discordance of morphological and molecular sy ...
1.3 Outlined inventory of a recent higher phylogeny14 of Caenophidian snakes15
1.3.1 Classification
1.4 General phylogenetic inventory of Caenophidian snakes: comments and consideration of known medical significance17
2 - Differences between buccal gland secretion and associated venom delivery systems of front-fanged snakes and non ...
2.1 Basic considerations regarding gland structure and function
2.2 Overview of hypotheses for the evolution of venom-delivery systems and other adaptive gland functions
2.3 Theories considering the evolution of canaliculated fangs and enlarged grooved teeth
2.4 Low-pressure ‘Duvernoy's glands’ and high-pressure venom glands: a question of semantics?
3 - A brief overview of the history of non-front-fanged snake venom research
3.1 Background and beginnings
3.2 The modern era: advances and attributions
3.3 A brief overview of major classes of non-front-fanged colubroid venom components (see Tables 3.2–3.4)2
3.3.1 Three-finger-fold toxins (3-FFTXs)
3.3.2 Cysteine-rich secretory proteins (CRiSPs)
3.3.3 Snake venom metalloproteases (SVMPs), matrix metalloproteases (MMPs), and snake venom serine proteases (SVSPs)
3.3.4 Phospholipases A2 and B (PLA2 and PLB)
3.3.5 ‘Other’ components
3.3.6 A comment on the hypothesized assignment of snake venom toxins to clinical effects of envenoming: causality and strength of ...
3.3.7 Illumination of biological function: prey-specificity and research trends
3.3.8 Immunology of non-front-fanged snake venoms
3.3.9 Commercial antivenoms against medically important elapids and viperids: possible use for envenoming by non-front-fanged sna ...
3.3.10 Future research
4 - Medically significant bites by non-front-fanged snakes (NFFCs)
4.1 Typical features of documented cases and evidence-based risk
4.1.1 Published and communicated or managed cases of medically significant non-front-fanged colubroid bites: summaries and streng ...
4.1.2 Epidemiology of bites from non-front-fanged snakes
4.1.2.1 South America
4.1.2.2 India
4.1.2.3 Bangladesh
4.1.2.4 Thailand
4.1.2.5 Myanmar (Burma)
4.1.2.6 Sri Lanka
4.1.2.7 Kenya
4.1.2.8 Nigeria
4.1.2.9 Middle East
4.1.2.10 Guam: a distinctive set of circumstances
4.1.3 Circumstances associated with species capable of inflicting life-threatening envenoming
4.2 Some representative genera: typical features of bites and an overview of their natural history and toxinology13
Colubridae, Ahaetuliinae
4.2.1 Genus Chrysopelea (Boie, 1826): background and general features of documented bites
4.2.1.1 Overview of the Duvernoy's venom gland and associated dentition of Chrysopelea spp.
4.2.1.2 Summary of the toxinology and properties of venom from Chrysopelea spp.
4.2.1.3 Conclusion and assessment of Chrysopelea ornata, C. paradisi, C. taprobanica, and C. pelias
Colubridae, Colubrinae
4.2.2 Genera Boiga (Fitzinger, 1826), and Toxicodryas (Hallowell, 1857): background and general features of documented bites
4.2.2.1 Overview of the Duvernoy's venom gland and associated dentition of Boiga spp. and Toxicodryas spp.
4.2.2.2 Summary of the toxinology and properties of venom from Boiga spp. and Toxicodryas blandingi (excluding detailed discussion ...
4.2.2.3 Conclusion and assessment of Boiga spp. and Toxicodryas spp.
4.2.3 Genera Hemorrhois (Boie, 1826), Platyceps (Blyth, 1860), Hierophis (Fitzinger in Bonaparte, 1834), Dolichophis (Gistel, 186 ...
4.2.3.1 Overview of the Duvernoy's venom gland and associated dentition of Hemorrhois, Platyceps, Hierophis, and Coluber
4.2.3.2 Summary of the toxinology and venom properties of Hemorrhois spp., Platyceps spp., Hierophis spp., and Coluber constrictor ssp.
4.2.3.3 Conclusion and assessment of Hemorrhois spp., Platyceps spp., Hierophis spp., and Coluber constrictor ssp.
Dipsadidae
4.2.4 Genus Philodryas (Wagler, 1830): background and general features of documented bites
4.2.4.1 Overview of the Duvernoy's venom gland and associated dentition of Philodryas spp.
4.2.4.2 Summary of the toxinology and properties of venom from Philodryas spp.
4.2.4.3 A “Modeled” species: summary of experimental pathophysiological effects of venom from P. patagoniensis
4.2.4.4 Reported fatal outcome from a P. olfersii bite: rumor or reality?
4.2.4.5 Conclusion and Assessment of Philodryas spp.
4.2.5 Genus Heterodon (Latreille, 1801): background and general features of documented bites
4.2.5.1 Overview of the Duvernoy's venom gland and associated dentition of Heterodon spp.
4.2.5.2 Summary of the toxinology and venom properties of Heterodon spp.
4.2.5.3 Can Heterodon nasicus inflict systemic envenoming?
4.2.5.4 Conclusion and assessment of Heterodon spp.
4.2.6 Genera Borikenophis and Cubophis (Hedges et al., 2009): background and general features of documented bites
4.2.6.1 Overview of the Duvernoy's venom gland and associated dentition of Borikenophis portoricensis and Cubophis cantherigerus
4.2.6.2 Summary of venom properties and toxinology of Borikenophis portoricensis
4.2.6.3 Borikenophis portoricensis venom: investigations of function
4.2.6.4 Conclusion and assessment of the Alsophiini: Borikenophis and Cubophis
Natricidae
4.2.7 Genus Thamnophis (Fitzinger, 1843) and comments on genus Nerodia (Baird and Girard, 1853): background and general features ...
4.2.7.1 Overview of the Duvernoy's venom gland and associated dentition of Thamnophis spp.
4.2.7.2 Summary of the toxinology, properties, and pathophysiology of venom from Thamnophis spp.
4.2.7.3 Comments about North American water snakes, Nerodia spp.
4.2.7.4 Conclusion and assessment of Thamnophis and Nerodia
Psammophiidae4747This section is focused on only Psammophis spp. that have some clinical evidence allowing analyses of thei ...
4.2.8 Genus Psammophis (Boie, 1825): background and general features of documented bites
4.2.8.1 Overview of the Duvernoy's venom gland and associated dentition of Psammophis spp.
4.2.8.2 Summary of the toxinology of venom from Psammophis spp.
4.2.8.3 Conclusion and assessment of Psammophis spp.
4.2.9 Summarized consideration of representative species with limited evidence
4.2.9.1 Glossy snake, Arizona elegans (Kennicott, 1859)
4.2.9.2 Yellow-tailed cribo; limpa-pasto, Drymarchon corais (Boie, 1827)
4.2.9.3 Mandarin rat snake, Euprepiophis mandarinus (Cantor, 1842)
4.2.9.4 Eastern rat snake, Pantherophis alleghaniensis (Holbrook, 1836)
4.2.9.5 Black or western rat snake, Pantherophis obsoletus (Say, 1823)
4.2.9.6 African bush snake, Philothamnus (Smith, 1847)
4.2.9.7 Rhinoceros rat snake, Gonyosoma boulengeri (Mocquard, 1897)
4.2.9.8 Red-tailed green rat snake, Gonyosoma oxycephalum (Boie, 1827)
4.2.9.9 Ringneck snake, Diadophis punctatus edwardsi (Merrem, 1820)
4.2.9.10 Comments on summarized representative cases with limited evidence
4.3 Life-threatening and fatal cases: non-front-fanged snakes with lethal potential and assessment of evidence-based risk
4.3.1 Dispholidus typus (Smith, 1828), Thelotornis capensis (Smith, 1849), and Thelotornis kirtlandii (Hallowell, 1844); Colubrid ...
4.3.1.1 Thelotornis envenoming: a broken levee without a dam
4.3.1.2 Dispholidus typus envenoming and the arts. Risks: real and imagined
4.3.1.3 Overview of the Duvernoy's venom gland and associated dentition of D. typus and Thelotornis spp.
4.3.1.4 Overview of the properties, toxinology, and pharmacology of venoms of D. typus and Thelotornis spp.
4.3.1.5 Dispholidus typus: a colubrid important in veterinary medicine
4.3.1.6 Conclusion and assessment of D. typus and Thelotornis spp.
4.3.2 Rhabdophis subminiatus (Schlegel, 1837), Rhabdophis tigrinus (Boie, 1826), and Rhabdophis ceylonensis (Günther, 1858); Natr ...
4.3.2.1 Overview of the Duvernoy's venom gland and associated dentition of R. subminiatus and R. tigrinus
4.3.2.2 The unusual nucho-dorsal glands of Rhabdophis spp. with focus on Rhabdophis tigrinus and toxin ophthalmia
4.3.2.3 Overview of the properties, toxinology, and pharmacology of venoms of R. subminiatus and R. tigrinus
4.3.2.4 Summary of experimental pathophysiological effects of venom from R. tigrinus tigrinus
4.3.2.5 Conclusion and assessment of R. subminiatus, R. tigrinus, and R. ceylonensis
4.3.3 Comparison of major features of hazard level 1 non-front-fanged snakes (Fig. 4.2) (Dispholidus typus, Thelotornis capensis, ...
4.3.4 Guilty without a trial: three additional unsupported reports of fatal outcomes after bites by Tachymenis peruviana (Wiegman ...
4.3.4.1 Tachymenis peruviana: an Undeserved reputation of lethal potential?
4.3.4.2 Oligodon arnensis: deadly fear without a cause?
4.3.4.3 A fatal bite by Xenodon severus?
4.4 Aberrant cases and representative cases without clear etiology: a critical assessment of risk
4.4.1 Boiga irregularis (Bechstein, 1802) (Colubridae, Colubrinae)
4.4.1.1 Background, history, and aberrant features of bites
4.4.1.2 Overview of the Duvernoy's venom gland and associated dentition of B. irregularis
4.4.1.3 Summary of the properties, toxinology, and variability of B. irregularis venom
4.4.1.4 What is the etiology of the medical effects of B. irregularis bites?
4.4.1.5 Conclusion and assessment of B. irregularis
4.4.2 Malpolon monspessulanus (Hermann, 1804) (Psammophiidae)
4.4.2.1 Background and aberrant features of bites
4.4.2.2 Overview of the Duvernoy's venom gland and associated dentition of M. monspessulanus
4.4.2.3 Summary of the properties and toxinology of M. monspessulanus venom
4.4.2.4 Does M. monspessulanus produce neurotoxic envenoming?
4.4.2.5 Conclusion and assessment of M. monspessulanus
4.4.3 Hydrodynastes gigas (Duméril et al., 1854), Dipsadidae
4.4.3.1 Background of an aberrant Case
4.4.3.2 Overview of the Duvernoy's venom gland and associated dentition of H. gigas
4.4.3.3 Summary of the properties and toxinology of H. gigas Venom
4.4.3.4 Analysis and conclusions
4.4.4 Philodryas olfersii latirostris (Cope, 1863), Dipsadidae
4.4.4.1 Background and consideration of an aberrant case
4.4.4.2 Commentary and critique
4.4.4.3 Conclusion and assessment of P. o. latirostris
4.4.5 Platyceps najadum (Eichwald, 1831) [Colubridae, Colubrinae]: a fatal case of progressive neuropathy from a colubrid bite?
4.4.5.1 Analysis and critique of an aberrant report
4.4.5.2 Conclusion and assessment of P. najadum
4.4.6 Hierophis viridiflavus (Lacépède, 1789) [Colubridae, Colubrinae]: a case of neurotoxic colubrine bite or a more common etio ...
4.4.6.1 Analysis and critique
4.4.6.2 Conclusion and assessment of H. viridiflavus
4.4.7 “Venomous” bites by non-venomous lizards?
4.4.7.1 “Venomous varanids”: clinical correlation or contradiction?
4.5 Pitfalls noted in documented cases: Differentiating Perceived versus Evidence-Based Risk
4.5.1 Examples of pitfalls noted in documented cases
4.5.1.1 Lack of verified identity of snakes responsible for reported bites
4.5.1.1.1 Conclusions and recommendations
4.5.1.1.1 Conclusions and recommendations
4.5.1.2 Lack of qualified medical assessment/review
4.5.1.2.1 Conclusions and recommendations
4.5.1.2.1 Conclusions and recommendations
4.5.1.3 Frequent authorship (“auto-reporting”) of snakebite cases by victims
4.5.1.3.1 Conclusions and recommendations
4.5.1.3.1 Conclusions and recommendations
4.5.1.4 Lack of established linkage between reported serious symptoms and the snakebite
4.5.1.4.1 Conclusions and recommendations
4.5.1.4.1 Conclusions and recommendations
4.5.1.5 Insufficient or irrelevant documentation of history and clinical features/analysis
4.5.1.5.1 Conclusions and recommendations
4.5.1.5.1 Conclusions and recommendations
4.5.1.6 Phalotris lemniscatus (Duméril et al., 1854) [Dumeril's diadem snake; Dipsadidae] revisited: evidence of risk or risky evid ...
4.5.1.6.1 Conclusions and considerations
4.5.1.6.1 Conclusions and considerations
4.5.2 Perceived versus evidence-based risk: human response to trauma and somatosensory amplification
4.6 Recommendations for management of medically significant non-front-fanged snake bites
4.6.1 General
4.6.2 Specific
4.6.2.1 First aid
4.6.2.2 Evaluation of the patient
4.6.2.3 Confirmation of snake identification
4.6.2.4 Toxinologist consultation
4.6.2.5 Wound care
4.6.2.6 Basic supportive measures
4.6.2.7 Antivenom
4.6.2.7.1 Antivenom against D. typus
4.6.2.7.1 Antivenom against D. typus
4.6.2.7.2 Reactions to SAVP (SAIMR) Anti-D. typus antivenom
4.6.2.7.2 Reactions to SAVP (SAIMR) Anti-D. typus antivenom
4.6.2.7.3 A further comment on Thelotornis envenoming and the lack of commercial antivenom
4.6.2.7.3 A further comment on Thelotornis envenoming and the lack of commercial antivenom
4.6.2.7.4 Antivenom against R. tigrinus
4.6.2.7.4 Antivenom against R. tigrinus
4.6.2.7.5 Treatment of R. subminiatus envenoming
4.6.2.7.5 Treatment of R. subminiatus envenoming
4.6.2.7.6 Polyvalent antivenoms should not be used for treating nonfront-fanged colubroid bites
4.6.2.7.6 Polyvalent antivenoms should not be used for treating nonfront-fanged colubroid bites
4.6.2.8 Replacement therapy
4.6.2.8.1 Blood transfusions and PRBCs
4.6.2.8.1 Blood transfusions and PRBCs
4.6.2.8.2 FFP and cryoprecipitate
4.6.2.8.2 FFP and cryoprecipitate
4.6.2.8.3 Recombinant human thrombomodulin
4.6.2.8.3 Recombinant human thrombomodulin
4.6.2.8.4 Platelets
4.6.2.8.4 Platelets
4.6.2.9 Heparin, antifibrinolytics, vitamin K, and adrenocorticotrophic hormone
4.6.2.9.1 Heparin
4.6.2.9.1 Heparin
4.6.2.9.2 Antifibrinolytics, vitamin K, and ACTH
4.6.2.9.2 Antifibrinolytics, vitamin K, and ACTH
4.6.2.10 Prothrombin and direct thrombin inhibitors
4.6.2.11 Plasmapheresis/exchange transfusion
4.6.2.12 Diuretics and dialysis: the causes and management of acute kidney injury (AKI) after bites of hazard level 1 nonfront-fange ...
4.6.2.13 Imaging studies
4.6.2.14 Additional investigations
4.6.2.15 Microbiology of the ophidian oropharynx and the use of antibiotics for medically significant non-front-fanged snake bites
4.6.2.15.1 Overview of microbial flora
4.6.2.15.1 Overview of microbial flora
4.6.2.15.2 Does Clostridium tetani occur in the ophidian oropharynx?
4.6.2.15.2 Does Clostridium tetani occur in the ophidian oropharynx?
4.6.2.15.3 Antibiotics should not be used prophylactically for non-necrotic snakebites
4.6.2.15.3 Antibiotics should not be used prophylactically for non-necrotic snakebites
4.6.2.16 Cautions and contraindications
4.6.2.17 Additional considerations: the possible role of hypersensitivity in the effects of non-front-fanged snake bites
5 - Summary and conclusions
A - Representative unverified cases of medically significant non-front-fanged snake bites posted on the internet11 ...
Case 1. Western hognose snake, Heterodon nasicus
Website
Website
Features of the case
Features of the case
Comments
Comments
Case 2. Jackson's black tree snake, Thrasops jacksoni
Website
Website
Features of the case
Features of the case
Comments
Comments
Case 3. Mangrove snake, Boiga dendrophila
Websites
Websites
Features of the case
Features of the case
Comments
Comments
B - Representative lethal potency ranges and yields of venoms and other oral products from selected non-front-fang ...
C - Strategies for management of gram-negative septicemia: are there lessons to be learned for managing venom-indu ...
D - Legal considerations regarding private ownership of venomous snakes (including hazard level 1 non-front fanged ...
E - List of examined osteological specimens
Additional recommended reading
Aiding the envenomated patient and further information: societies, journals, toxinology courses, and associated contacts
Seeking advice for management of a patient bitten by a non-front-fanged colubroid snake
Seeking advice for management of a patient bitten by a non-front-fanged colubroid snake
Societies and periodicals
Societies and periodicals
Formal training in clinical toxinology
Formal training in clinical toxinology
Bibliography
News Periodicals Cited
Glossary
A call for cases
Index
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