Skip to main navigation menu Skip to main content Skip to site footer

Original article

Vol. 152 No. 0304 (2022)

Exotic venomous snakebites in Switzerland reported to the National Poisons Information Centre over 22 years

  • Joan Fuchs
  • Tim Gessner
  • Hugo Kupferschmidt
  • Stefan Weiler
Cite this as:
Swiss Med Wkly. 2022;152:w30117


OBJECTIVE: The private keeping of exotic venomous snakes is legally permitted in Switzerland. The aim of the present study was to characterise the epidemiological and clinical features of bites by exotic venomous snakes over a period of 22 years in Switzerland.

METHODS: We included all calls related to exotic snakebites recorded at the Swiss National Poisons Information Centre (Tox Info Suisse) from 1997 to 2018. Exclusion criteria comprised indigenous snakes, non-venomous exotic snakes such boas or pythons, clinical courses incompatible with a snakebite or calls from abroad. Follow-up information was graded according to the Poisoning Severity Score.

RESULTS: Within the study period, 1,364 calls related to snakebites were recorded at Tox Info Suisse; 148 (11%) cases were attributed to exotic venomous snakes and fulfilled the study criteria. A total of 112 (98%) of 114 patients with medical follow-up information exhibited sufficient causality between exposure and clinical effects. Only adult patients were affected. The median age was 40 years (range 16–71) and the male gender was predominant (n = 136, 92%). Viperidae were involved in 87 (78%) and Elapidae in 25 (22%) patients. Overall, the main affected body part was the hand (89 patients, 79%). In the majority of the patients the clinical course was mild (46, 41%) or moderate (40, 36%), in a lower proportion asymptomatic (6, 5%) or with severe symptoms (20, 18%). No fatalities were reported in the study period. Severe symptoms were observed after elapid bites in six patients (24%) and after viper bites in 14 patients (16%). Besides local effects, neurological disorders after elapid bites and haematological disorders after viper bites were most frequently reported. Antivenom was administered in 24% (27 patients: 18 Viperidae, 21% and 9 Elapidae, 36%; 5 patients (4%) required multiple doses), overall, with good resolution of symptoms.

CONCLUSION: Exotic snakebite is a rare occurrence in Switzerland but has led to medically relevant morbidity, sometimes requiring antivenom treatment. Over half of the envenomed patients required symptomatic or specific treatment. No fatalities or bites in children were reported.


  1. Plate A, Kupferschmidt H, Schneemann M. [Bites of venomous snakes in Switzerland]. Praxis (Bern 1994). 2016;105(12):679-85; quiz 684-5. doi:
  2. Ng VC, Lit AC, Wong OF, Tse ML, Fung HT. Injuries and envenomation by exotic pets in Hong Kong. Hong Kong Med J. 2018 Feb;24(1):48–55.
  3. McNally J, Boesen K, Boyer L. Toxicologic information resources for reptile envenomations. Vet Clin North Am Exot Anim Pract. 2008 May;11(2):389–401.
  4. Greene SC, Osborn L, Bower R, Harding SA, Takenaka K. Monocled Cobra (Naja kaouthia) envenomations requiring mechanical ventilation. J Emerg Med. 2021 Feb;60(2):197–201.
  5. Coulson JM, Cooper G, Krishna C, Thompson JP. Snakebite enquiries to the UK National Poisons Information Service: 2004-2010. Emerg Med J. 2013 Nov;30(11):932–4.
  6. de Haro L, Pommier P. Envenomation: a real risk of keeping exotic house pets. Vet Hum Toxicol. 2003 Aug;45(4):214–6.
  7. Lubich C, Krenzelok EP. Exotic snakes are not always found in exotic places: how poison centres can assist emergency departments. Emerg Med J. 2007 Nov;24(11):796–7.
  8. Warrick BJ, Boyer LV, Seifert SA. Non-native (exotic) snake envenomations in the U.S., 2005-2011. Toxins (Basel). 2014 Sep;6(10):2899–911.
  9. Miller SW, Osterhoudt KC, Korenoski AS, Patel K, Vaiyapuri S. Exotic snakebites reported to Pennsylvania Poison Control Centers: lessons learned on the demographics, clinical effects, and treatment of these cases. Toxins (Basel). 2020 Nov;12(12):755.
  10. Min YG, Ham SH, Jung YS, Choi S. Gaboon viper envenomation: an unexpected injury by non-indigenous snake in South Korea. Turk J Emerg Med. 2018 Apr;18(2):75–7.
  11. Minkley L, Overkamp D, Fischer J. Schlangen als Haustiere - ein exotisches Hobby und seine Folgen [Snakes as pets - consequences of an exotic hobby]. Dtsch Med Wochenschr. 2013;138(50):2619. German. doi:
  12. Warrell DA. Commissioned article: management of exotic snakebites. QJM. 2009 Sep;102(9):593–601.
  13. D’Hoore L, Anseeuw K. Preparing for venomous snake bites in Europe. Eur J Emerg Med. 2020 Aug;27(4):247–8.
  14. Persson HE, Sjöberg GK, Haines JA, Pronczuk de Garbino J. Poisoning severity score. Grading of acute poisoning. J Toxicol Clin Toxicol. 1998;36(3):205–13.
  15. Di Nicola MR, Pontara A, Kass GE, Kramer NI, Avella I, Pampena R, et al. Vipers of Major clinical relevance in Europe: Taxonomy, venom composition, toxicology and clinical management of human bites. Toxicology. 2021 Apr;453:152724.
  16. Debien B, Mion G. Envenimation par serpent exotique en France: risque ou menace? [Envenoming by exotic snake in France: risks or threatens?]. Ann Fr Anesth Reanim. 2008;27(4):289-91. French. doi:
  17. Warwick C, Steedman C. Injuries, envenomations and stings from exotic pets. J R Soc Med. 2012 Jul;105(7):296–9.
  18. Quarch V, Brander L, Cioccari L. An unexpected case of Black Mamba (Dendroaspis polylepis) Bite in Switzerland. Case Rep Crit Care. 2017;2017:5021924.
  19. Stadelmann M, Ionescu M, Chilcott M, Berney JL, Gétaz L. Morsures de serpents exotiques en Suisse [Exotic snake bites in Switzerland]. Rev Med Suisse. 2010 May;6(248):969–72.
  20. Seifert SA, Oakes JA, Boyer LV. Toxic Exposure Surveillance System (TESS)-based characterization of U.S. non-native venomous snake exposures, 1995-2004. Clin Toxicol (Phila). 2007 Jun-Aug;45(5):571–8.
  21. Valenta J, Stach Z, Michalek P. Exotic snake bites in the Czech Republic—epidemiological and clinical aspects during 15-year period (1999-2013). Clin Toxicol (Phila). 2014 Apr;52(4):258–64.
  22. Paolino G, Di Nicola MR, Pontara A, Didona D, Moliterni E, Mercuri SR, et al. Vipera snakebite in Europe: a systematic review of a neglected disease. J Eur Acad Dermatol Venereol. 2020 Oct;34(10):2247–60.
  23. BLV. Tierschutzverordnung [Internet] 2008 [accessed 2021 June 16]. Available from:
  24. Anforderungen für die Haltung von Giftschlangen [Internet]:; 2019 [accessed 2021 June 15]. Available from:
  25. Moritz J. Anforderungen an die Haltung gefährlicher Tiere [Requirements for the keeping of dangerous exotic animals] [German.]. Dtsch Tierarztl Wochenschr. 2003 May;110(5):224–6.
  26. Jaramillo JD, Hakes NA, Tennakoon L, Spain D, Forrester JD. The “T’s” of snakebite injury in the USA: fact or fiction? Trauma Surg Acute Care Open. 2019 Oct;4(1):e000374.
  27. Baudou FG, Rodriguez JP, Fusco L, de Roodt AR, De Marzi MC, Leiva L. South American snake venoms with abundant neurotoxic components. Composition and toxicological properties. A literature review. Acta Trop. 2021 Dec;224:106119.
  28. Warrell DA. Venomous bites, stings, and poisoning: an Update. Infect Dis Clin North Am. 2019 Mar;33(1):17–38.
  29. Meyer S, Hartmann F, Stein P, Lenherr R, Fuchs J, Spahn DR. Massive coagulopathy caused by the bite of a Crotalus basiliscus snake. Anaesthesia Cases. 2017.
  30. Schneemann M, Cathomas R, Laidlaw ST, El Nahas AM, Theakston RD, Warrell DA. Life-threatening envenoming by the Saharan horned viper (Cerastes cerastes) causing micro-angiopathic haemolysis, coagulopathy and acute renal failure: clinical cases and review. QJM. 2004 Nov;97(11):717–27.
  31. Bernheim A, Lorenzetti E, Licht A, Markwalder K, Schneemann M. Three cases of severe neurotoxicity after cobra bite (Naja kaouthia). Swiss Med Wkly. 2001 Apr;131(15-16):227–8.
  32. Fuchs J, Faber K, Tuchscherer DT, Tsakiris DA, Weiler S, Hofer KE. Bite by a juvenile Bothrops venezuelensis (Venezuelan lancehead) resulting in severe envenomation: A case report. Toxicon. 2020 Jun;180:39–42.
  33. Fuchs J, Weiler S, Meier J. Envenomation by a western green mamba (Dendroaspis viridis) - A report of three episodes in Switzerland. Toxicon. 2019 Oct;168:76–82.
  34. Valente-Aguiar MS, Gonçalves da Costa E Silva B, Magalhães T, Dinis-Oliveira RJ, Dinis-Oliveira RJ. Compartment Syndrome following Bothrops Snakebite Leads to Decompressive Fasciotomies. Case Rep Med. 2019 Mar;2019:6324569.
  35. Hall EL. Role of surgical intervention in the management of crotaline snake envenomation. Ann Emerg Med. 2001 Feb;37(2):175–80.
  36. Lavonas EJ, Ruha AM, Banner W, Bebarta V, Bernstein JN, Bush SP, et al.; Rocky Mountain Poison and Drug Center, Denver Health and Hospital Authority. Unified treatment algorithm for the management of crotaline snakebite in the United States: results of an evidence-informed consensus workshop. BMC Emerg Med. 2011 Feb;11(1):2.
  37. Edgerton MT, Koepplinger ME. Management of Snakebites in the Upper Extremity. J Hand Surg Am. 2019 Feb;44(2):137–42.
  38. Cumpston KL. Is there a role for fasciotomy in Crotalinae envenomations in North America? Clin Toxicol (Phila). 2011 Jun;49(5):351–65.
  39. de Haro L. Management of snakebites in France. Toxicon. 2012 Sep;60(4):712–8.
  40. Website of the Antivenom Network Switzerland [Internet]:, [accessed 2021 June 14]. Available from:
  41. Dorner-Schulmeister S, Schneeweiss-Gleixner M, Bartecka-Mino K. Rattlesnake bite in Austria: a case report. Clin Tox (Phila). (2021) 41st International Congress of the European Association of Poisons Centres and Clinical Toxicologists (EAPCCT) 25-28 May 2021, Virtual Meeting, Clinical Toxicology, 59:6, 537-602, doi:
  42. Malina T, Krecsák L, Korsós Z, Takács Z. Snakebites in Hungary—epidemiological and clinical aspects over the past 36 years. Toxicon. 2008 May;51(6):943–51.
  43. Hoffman RS. Understanding the limitations of retrospective analyses of poison center data. Clin Toxicol (Phila). 2007 Dec;45(8):943–5.
  44. Fuchs J, Bessire K, Weiler S. A confirmed bite by a Beautiful Pit Viper (Trimeresurus venustus) resulting in local symptoms. Toxicon. 2019 May;163:44–7.

Most read articles by the same author(s)