ANIMAL BITES AND STINGS
TAOLE MOKOENA DPhil FRCS
DEPARTMENT OF SURGERY
UNIVERSITY OF PRETORIA
2013
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:
1. Wounding
2. Allergic reactions
3. Envenomation
4. “Exotic” disease transmission
WOUNDING THROUGH
BITES
1.
2.
3.
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
Mokoena & Cliff 1997
Mokoena & Cliff 1997
Mokoena & Cliff 1997
Mokoena & Cliff 1997
Mokoena & Cliff 1997
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
Woolgar et al 2001
Woolgar et al 2001
Woolgar et al 2001
Mokoena & Cliff 1997
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
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
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
Graft 2006
ALLERGIC REACTIONS
1.
2.
3.
4.
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)
EXOTIC DISEASE
TRANSMISSION
1.
2.
3.
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
ENVENOMATION
1.
2.
3.
•
•
•
•
•
4.
5.
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
Prophylaxis
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.
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.
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