Snake envenoming is a major problem in Africa however the epidemiology is poorly described because many cases are not treated in hospital or health care facilities. In many parts of the Continent there is a the lack of immediate health care and antivenom. There remains very limited information the clinical effects of many snakes, with only published single cases, often in snake handlers in other countries. The table provides a summary of the clinical effects of the major snakes in Africa.


Table 1: A summary of the major African snakes, their clinical effects and antivenoms that are available. Detailed information on the distribution of each snake group is available at toxinology.com.
Common Name
Scientific Name
Clinical Effects
Antivenom1
African carpet vipers
Echis ocellatus, E. pyramidum, E. coloratus
VICC (prothrombin activator), major and minor bleeding; local effects and necrosis (10%); thrombotic microangiopathy (acute kidney injury and thrombocytopenia)1-4
FAV-Afrique and SAIMR Echis antivenom
Desert and horned vipers
Cerastes cerastes, C. vipera
Local effects (haemorrhagic bullae, swelling) are the most common, uncommonly VICC and rarely thrombotic microangiography.5-7
Antivenoms made in Egypt, Tunisia, Algeria and Saudi arabia
Bush vipers
Atheris spp.
VICC (thrombin like enzyme) with major and minor bleeding, thrombotic microangiopathy and local tissue injury.8-10
No antivenom
African spitting cobras
Naja nigricollis, N. mossambicus, N. katiensis, N.pallida
  1. Chemical injury to eyes (venom ophthalmia) causing pain, oedema, blepharospasm and leucorrhoea, less commonly corneal ulcers and injury to the anterior chamber/infection.11, 12
  2. Cytotoxic local effects with local swelling, then blistering and necrosis of skin and subcutaneous tissues; non-specific systemic effects and rarely bleeding.13, 14
FAV-Afrique and Egyptian polyvalent antivenom (for bites not ophthalmia)
Neurotoxic Cobras (Egyptian cobra)
Naja haje
Non-specific systemic symptoms, local effects (not necrosis) and progressive neurotoxicity that may require intubation.15
Egyptian polyvalent antivenom and FAV-Afrique, and others.
Mambas
Dendroaspis spp.
Mild local effects, non-specific symptoms, generalised diaphoresis, paraesthesias, tachycardia, hypertension, hypotension, dsypnoea and pulmonary oedema, neurotoxicity (paralysis and neuromuscular excitation with fasciculations). 16, 17
SAIMR polyvalent snake antivenom
Puff Adder
Bitis arietans
Local effects (swelling, blistering and necrosis) are common; hypotension, thrombocytopenia and rarely partial VICC (low fibrinogen)18, 19
SAIMR polyvalent snake antivenom + others.
Gaboon viper
Bitis gabonica
Local effects (less severe than puff adder), but significant coagulopathy due to a TLE in the venom.20
SAIMR polyvalent snake antivenom + others.
Boomslang
Dispholidus typus
Minimal local effects, VICC and rarely thrombotic microangiography.21
SAIMR boomslang antivenom
Burrowing asps
Atractaspis spp.
Moderate local effects including local swelling, and rarely blistering or minor necrosis, non-specific symptoms.22
No specific antivenom is available.
Night Adders
Causus spp.
Local pain, swelling and lymphadenopathy.23
No antivenom

1 More information on antivenoms available at the WHO website: http://apps.who.int/bloodproducts/snakeantivenoms/database/snakeframeset.html; VICC – venom induced consumption coagulopathy; SAIMR – South African Institute of Medical Research;

References

1. Warrell DA, Davidson NM, Greenwood BM, Ormerod LD, Pope HM, Watkins BJ, et al. Poisoning by bites of the saw-scaled or carpet viper (Echis carinatus) in Nigeria. Quarterly Journal of Medicine. 1977; 46(181): 33-62.
2. Gillissen A, Theakston RD, Barth J, May B, Krieg M, Warrell DA. Neurotoxicity, haemostatic disturbances and haemolytic anaemia after a bite by a Tunisian saw-scaled or carpet viper (Echis 'pyramidum'-complex): failure of antivenom treatment. Toxicon. 1994; 32(8): 937-44.
3. Mion G, Larreche S, Benois A, Petitjeans F, Puidupin M. Hemostasis dynamics during coagulopathy resulting from Echis envenomation. Toxicon. 2013; 76: 103-9.
4. Porath A, Gilon D, Schulchynska-Castel H, Shalev O, Keynan A, Benbassat J. Risk indicators after envenomation in humans by Echis coloratus (mid-east saw scaled viper). Toxicon. 1992; 30(1): 25-32.
5. Zimmerman J, Mann G, Kaplan HY, Sagher U. Envenoming by Cerastes viper - a report of two cases. Trans R Soc Trop Med Hyg. 1981; 75(5): 702-5.
6. Lifshitz M, Kapelushnik J, Ben-Harosh M, Sofer S. Disseminated intravascular coagulation after cerastes vipera envenomation in a 3-year-old child: a case report. Toxicon. 2000; 38(11): 1593-8.
7. 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; 97(11): 717-27.
8. Top LJ, Tulleken JE, Ligtenberg JJ, Meertens JH, van der Werf TS, Zijlstra JG. Serious envenomation after a snakebite by a Western bush viper (Atheris chlorechis) in the Netherlands: a case report. Neth J Med. 2006; 64(5): 153-6.
9. Mebs D, Holada K, Kornalik F, Simak J, Vankova H, Muller D, et al. Severe coagulopathy after a bite of a green bush viper (Atheris squamiger): case report and biochemical analysis of the venom. Toxicon. 1998; 36(10): 1333-40.
10. Hatten BW, Bueso A, French LK, Hendrickson RG, Horowitz BZ. Envenomation by the Great Lakes Bush Viper (Atheris nitschei). Clin Toxicol (Phila). 2013; 51(2): 114-6.
11. Chu ER, Weinstein SA, White J, Warrell DA. Venom ophthalmia caused by venoms of spitting elapid and other snakes: Report of ten cases with review of epidemiology, clinical features, pathophysiology and management. Toxicon. 2010; 56(3): 259-72.
12. Warrell DA, Ormerod LD. Snake venom ophthalmia and blindness caused by the spitting cobra (Naja nigricollis) in Nigeria. AmJ TropMedHyg. 1976; 25(3): 525-9.
13. Warrell DA, Greenwood BM, Davidson NM, Ormerod LD, Prentice CR. Necrosis, haemorrhage and complement depletion following bites by the spitting cobra (Naja nigricollis). QJ Med. 1976; 45(177): 1-22.
14. Tilbury CR. Observations on the bite of the Mozambique spitting cobra (Naja mossambica mossambica). S Afr Med J. 1982; 61(9): 308-13.
15. Warrell DA, Barnes HJ, Piburn MF. Neurotoxic effects of bites by the Egyptian cobra (Naja haje) in Nigeria. Transactions of the Royal Society of Tropical Medicine and Hygiene. 1976; 70(1): 78-9.
16. Zavada J, Valenta J, Kopecky O, Stach Z, Leden P. Black mamba dendroaspis polylepis bite: a case report. Prague Med Rep. 2011; 112(4): 298-304.
17. Hilligan R. Black mamba bites. A report of 2 cases. S Afr Med J. 1987; 72(3): 220-1.
18. Lavonas EJ, Tomaszewski CA, Ford MD, Rouse AM, Kerns WP, 2nd. Severe puff adder (Bitis arietans) envenomation with coagulopathy. J Toxicol Clin Toxicol. 2002; 40(7): 911-8.
19. Warrell DA, Ormerod LD, Davidson NM. Bites by puff-adder (Bitis arietans) in Nigeria, and value of antivenom. British Medical Journal. 1975; 4(5998): 697-700.
20. McNally T, Conway GS, Jackson L, Theakston RD, Marsh NA, Warrell DA, et al. Accidental envenoming by a Gaboon viper (Bitis gabonica): the haemostatic disturbances observed and investigation of in vitro haemostatic properties of whole venom. Trans R Soc Trop Med Hyg. 1993; 87(1): 66-70.
21. Aitchison JM. Boomslang bite--diagnosis and management. A report of 2 cases. S Afr Med J. 1990; 78(1): 39-42.
22. Tilbury CR, Branch WR. Observations on the bite of the southern burrowing asp (Atractaspis bibronii) in Natal. S Afr Med J. 1989; 75(7): 327-31.
23. Warrell DA, Ormerod LD, Davidson NM. Bites by the night adder (Causus maculatus) and burrowing vipers (genus Atractaspis) in Nigeria. AmJ TropMedHyg. 1976; 25(3): 517-24.