ANIMAL BITES AND STINGS

1. ANIMAL BITES AND STINGS TAOLE MOKOENA DPhil FRCS DEPARTMENT OF SURGERY UNIVERSITY OF PRETORIA 2013

2. BITES: ANIMALS, HUMANS, SNAKES AND INSECTS Humans are not prey to any animal! Humans do not form the sole source of food for any insect except few parasites such as lice, scabies, etc. Importance of bites are: • Wounding • Allergic reactions • Envenomation • “Exotic” disease transmission

3. WOUNDING THROUGH BITES • General breach of epithelium - trauma - tetanus - other bacteria, e.g. vibrio spp • Inoculation with specific animal flora, e.g. Pasturella multicida, Cypnocytophaga carnimorsus carnemortis • Treatment directed at these - general debridement and delayed closure - Tetanus Prophylaxis - Antibacterial prophylaxis

4. Mokoena & Cliff 1997

5. Mokoena & Cliff 1997

6. Mokoena & Cliff 1997

7. Mokoena & Cliff 1997

8. Mokoena & Cliff 1997

9. Shark Attacks • Shark attacks are rare but attract much publicity esp since movies JAWS • About 50 attacks reported annually worldwide about 10% fatal. RSA accounts for 10% attacks • Main attacking shark species: • Great white (Carcharodon carcharias) • Tiger ( Galeocerdo curvier) : indiscriminate feeder • Bull (Zambezi) (Carcharhinus leucas): roams fresh water rivers • Most attacks are “non—aggression” and thus not fatal • Main fatalities associated with vascular injury and exsanguinating haemorrhage

10. Woolgar et al 2001

11. Woolgar et al 2001

12. Woolgar et al 2001

13. Mokoena & Cliff 1997

14. Management of Shark Injuries • Prevention • Shark nets • Modify human behaviour: prudent use of the oceans no discharge of raw offal and carcasses • Stop Haemorrhage and resuscitation • Save a life • Preserve function • Avoid complications

15. Insect Stings and Bites • Most are of nuisance value: minor local irritation • Some cause morbidity: Large local reaction • Very few can be fatal: anaphylactic reation • Anaphylactic reaction not predictable

16. Recommended Readings • TR Mokoena and G Cliff. Injury from bites: in Scientific Foundations of Trauma eds GJ Cooper, HAF Dudley etc al Chapter 26 p347-364. Butterworth-Heinemann Oxford 1997 • Woolgar JD, Cliff G, Nair R et al. Shark attack: Review of 86 Consecutive Cases. J Trauma 2001;50: 887-891 • Graft DF. Insect Sting Allergy Med.Clin. N.Am 2006;90: 211-232 • Braitberg G and Segal L. Spider bites: assessment and management. Australian Fair Physician 2009;38:862-867 • Klotz JH, Klotz SA, Pinnas JL. Animal bites and stings with anaphylactic pontential. J Emergency Med 2009; 36: 148-156

20. Graft 2006

21. ALLERGIC REACTIONS • Many insects and fish species induce allergic reactions, e.g. honey bees, wasps, spiders, scorpions • Atopic individual especially at risk • Treatment symptomatic - adrenalin - antihistamines - corticosteroids • Prophylaxis - skin testing - Venom Immunotheraphy (VIT)

22. EXOTIC DISEASE TRANSMISSION • Insect borne diseases especially viral but also parasitic, including rickettsia, trypanosomiasis, malaria • Rabies - endemic in South Africa - wild reservoir includes birds and rodents - dogs main transmitters to humans - no specific treatment except antiserum - Rabies control important • Human rabies vaccine - attenuated virus traditionally - genetically engineered vaccine now available

23. ENVENOMATION • Mostly from snakes • Most snakes harmless • Types of venom • cytopathic – tissue necrosis • Haemolytic – haemolysis • Haemorrhagic -DIC -Fibrinolytic • Cardiotoxic • Neurotoxic Most venoms are a mixture • Treatment - antivenom - supportive 5. Prophylaxis

24. VIPERIDAE – ADDERS – VENOM MOSTLY CYTOTOXIC MAJOR ADDERS Puff Adder A short, fat, sluggish snake which is common and aggressive; responsible for most serious bites. Gaboon Adder Very rare; found in the north eastern coastal areas of KwaZulu-Natal; important as its venom is very potent MINOR ADDERS Berg Adder Common in hiking areas of Drakensberg and Eastern Cape; important as, unlike other adders, the venom is neurotoxic. Horned Adder Erect scale above each eye; uncommon; found in drier areas of NE Cape and Namibia Night Adder Common; confused with egg eaters; bites not infrequent. Side Stabbing Adder Burrowing adder Not an adder but included in this group as it has cytotoxic venom; able to extrude its fangs from the side of its mouth; herpetologists frequently get bitten.

25. COLUBRIDAE – BOOMSLANG – VENOM MOSTLY HAEMOTOXIC Boomslang A long slender green snake with marked colour variation; may be olive brown; always a yellow belly and big eyes. Vine / twig snake An unusual and beautiful snake.

26. ELAPIDAE – COBRAS AND MAMBAS – VENOM MOSTLY NEUROTOXIC NEUROTOXIC SPECIES Mambas Black, green, Jameson’s; all very long large aggressive and highly dangerous snakes with a potent neurotoxin. Cobras Cape, forest, Egyptian; common and almost as dangerous. Rinkhals Has both cytotoxic and neurotoxic properties to its venom; it is a good spitter and excellent “shammer”. Others Coral and shield snakes, yellow-bellied sea snake; uncommon on South African shores. CYTOTOXIC SPECIES M’fezi Mozambique spitting cobra, black spitting cobra and barred cobras. Garter Snake Also neurotoxic features