Details about the most venomous types of snakes in Sri Lanka and the venomous arthropods along with information for the treatment of their bites.

1. VENOMOUS
SNAKES OF
SRI LANKA
Cobra, Russell'sViper, Kraits, Saw ScaledViper, Hump NosedViper,
Green PitViper

3. SHHHHHH….!!!
• Sri Lanka, though an island of relatively small size, is the richest country in
herpetological wealth in South Asia.
• Consists of approximately 100 amphibian and 190 reptile species. Of the reptiles,
96 species are snakes. Out of the 96 species, 35 are venomous. 20 of them are
considered extremely venomous. 13 of these snakes species are sea snakes. 61
species are non-venomous.
• Of the 61,000 snake-bites, a majority of which are non-venomous, recorded each
year at Sri Lankan state hospitals, about 27 % of the venomous bites are by the
Hump-nosed viper. An average of 800 people are killed by snakes very year. Over
95% fatalities are due to Sri Lankan Cobra, Common Krait & Russel’s pit viper.

4. SHHHHHH….!!!
• Important factors which contribute to this high incidence of
snakebite morbidity and mortality are:
• The presence of representatives of all the known snake families
which contain venomous species
• The favourable climates and habitats

5. SHHHHHH….!!!
• Clearing and alterations to the natural vegetation and habitats by
people for settlements, agriculture and plantations.
• In Sri Lanka, 85% of the circumstances in which snakebite took
place were while they engaged directly or indirectly in agricultural
activities or related pursuits such as weeding, preparation of fields,
harvesting, guarding fields.

6. COMMON IDENTIFYING FEATURES OF VENOMOUS
SNAKES
• A triangular or oval shaped head.
• Clear demarcation between the head, neck and the body.
• Tip of the tail is cone shaped.
• Cross section of the body is circular.
• Scales present on the head are small and are similar to those present
on the body.

7. SRI LANKAN COBRA
• Found right throughout the island, even in Colombo
• Often seen with snake charmers
• Common places :
• Lot of mice - Houses and storerooms
• Paddy fields

8. IDENTIFICATION POINTS
• A flattened, hooded shaped head
• A spectacles-shaped marking on its upper surface of the
head
• Adult snakes range from 1 to 1.5 metres (may grow to
lengths of 2.1 to 2.2 metres)
• Cylindrical bodies with long tails and smooth scales

9. METHODS OF DELIVERING THEIR
VENOM
• Spitting their venom into a victim's eyes, causing
extreme pain and blindness.
• Injecting into a victim's body through their bite

10. VENOM
• Contains postsynaptic neurotoxins
• Causing respiratory failure and, eventually, death
• Mechanism – inhibits cholinergic neurotransmission

11. SIGNS AND SYMPTOMS
• Neurological and Neuromuscular – early symptoms
• Respiratory paralysis or Dyspnoea (may develop quickly)
• Excessive salivation
• Drowsiness, Restlessness
• Sudden loss of consciousness, eyelid drooping (Ptosis)

12. SIGNS AND SYMPTOMS
• Ophthalmoplegia - paralysis of the muscles within or surrounding
the eye
• Palatal paralysis, Glossopharyngeal paralysis or Dysphagia,
Generalized convulsions, Fasciculations
• Head drooping (Cervical muscle paresis or paralysis), Headache,
Local pain or Numbness around bite site

13. SPECIFIC TREATMENT
• Polyvalent Antivenom - neutralizes the components of Cobra
venom
• Diluted (1:10) in Lactated Ringers Solution, given by intravenous
infusion at a rate of ONE vial per 10 minutes
• Respiratory obstruction and failure - Neostigmine and Atropine
can be given
• Fluid management

15. Russell's Viper
Daboia russelli russelli
තිත් ප ොළඟා / දාර ප ොළඟා / ගැට ප ොළඟා
അണലി

16. Identifying
features
• The biggest viper species found in Sri Lanka.
• Head is triangular with a clear neck. There is a
‘V’ mark on the head.
• The upper portion of the body is light brown.
There are 3 rows of spots spread along the
length of the body.The spots are dark brown.
Each of these spots has a black ring around it,
the outer border of which is intensified with a
rim of white or yellow.
• There is a zig zag pattern among the rows of
spots.The underside of the body is white.
• Grows to about 5.5 feet.

17. Epidemiological features
• Site: Elbow and below, knee and below
• Circumstances: Paddy fields, roads, footpaths at dawn
and dusk
Envenomation symptoms
• Local swelling, tissue necrosis
• Neurotoxicity (ptosis, external ophthalmoplegia)
• Coagulopathy (dark urine, prolonged clotting time,
incoagulable blood)
• Myotoxicity (myalgia, tender muscles, rhabdomyolysis)
• Acute renal failure

18. Treatment
• Dose: 100-200 ml (10-20 ampoules) or more- of Indian
polyspecific antivenom in 400 ml of normal saline infused
intravenously over one hour.
– The dose of antivenom depends on the severity of
envenoming—in acute, severe coagulopathy following
Russell’s viper bites up to 30 ampoules could be given.
• In viper bites — antivenom may be repeated in 6 hours in a
dose of 100 ml (10 ampules) if coagulopathy persists; the
endpoint of antivenom therapy is reversal of
coagulopathy as determined by serial performance of the
20WBCT.
• In viper bites, monitor the efficacy of antivenom by
repeatedly performing the 20 min. whole blood clotting
test (20WBCT) at the bedside.
• Repeat 20WBCT in 6 hours—if the blood does not clot in
20 minutes, repeat antivenom infusion and perform
20WBCT 6 hours later.
• Continue the cycle till the blood clots.

19. Hump Nosed Viper
Hypnale hypnale
කුණ කටුවා / ප ොපළාාන් පෙලිස්සා

20. Identifying
features
• Head is triangular with a distinct neck.
The snout is pointed and turned
upwards, ending in a hump.
• They raise the head at a 45˚ angle from
the ground.
• There is a pit between the nose and the
mouth.
• The dorsal aspect of the body is grey,
brown or orange with dark brown or
black mottling.
• There is a small nodule at the start of
the tail.

21. Epidemiological features
• Site: fingers and hand, ankle and foot
• Circumstances: paddy fields and forests, resting under
logs, dry leaves, etc.
Envenomation symptoms
• Local swelling, haemorrhagic blisters
• Coagulopathy (red urine, spontaneous bleeding,
incoagulable blood on 20WBCT)
• Acute renal failure

22. Treatment • Dose: 100-200 ml (10-20 ampoules) or more of Indian
polyspecific antivenom in 400 ml of normal saline
infused intravenously over one hour.
• In viper bites — antivenom may be repeated in 6 hours
in a dose of 100 ml (10 ampules) if coagulopathy
persists; the endpoint of antivenom therapy is reversal
of coagulopathy as determined by serial performance
of the 20WBCT.
• In viper bites, monitor the efficacy of antivenom by
repeatedly performing the 20 min. whole blood
clotting test (20WBCT) at the bedside.
• Repeat 20WBCT in 6 hours—if the blood does not clot
in 20 minutes, repeat antivenom infusion and perform
20WBCT 6 hours later.
• Continue the cycle till the blood clots.

23. The Common Krait /
Oil Krait
Bungarus caeruleus
පෙල් කරවලා / මග මරුවා

24. Identifying
features
• Very shiny (oil Krait).
• White bands throughout the body.
• With age white band disappear.
• Live individually or in pairs.
• Contribute to unknown deaths of Sri
Lanka (Biggest culprit).
• More venomous than the common
cobra.
• “Maga maruwa” – Death on way .

25. Epidemiological features
• Habitat: Commonly found in the Dry zone. Mainly
encountered at night (1 or 2 o’clock in the morning).
• Live individually or in pairs.
Venom
• Pure Neurotoxin, 16 times powerful than that of the
cobra.
• Venom acts on the neuromuscular junction.
• 90% of krait bites are from respiratory failure.

26. Treatment • Abnormal cramps misdiagnosed as stomach pain.
• Anti-venom should be administered immediately if
not, will have to probably introduce a respiratory
ventilator.
• Ultimate respiratory failure if untreated.

27. Sri Lankan Green
Pit Viper
Trimeresurus trigonocephalus
ළා ප ොළඟා

28. Identifying
features
• Mid sized, cylindrical in shape.
• Males are considerably smaller than
female.
• Females are predominantly green in
colour.
• Males tend to have a blue coloration.
• Tail is black.
• Reproduction –Viviparous; about 25
young are produced at once.
• Sexually dimorphic.

29. • Geographic range: Endemic to Sri Lanka, widely distributed in all
three climatic zones of the island, except higher hills
and arid zones.
• Behavior:Arboreal, nocturnal, diet consists of lizards, frogs,
small mammals, and birds, usually encountered on low shrubs
during morning hours.
• Primarily haemotoxic.
• Severe pain and swelling of the bitten area.
• Oedema and blisters with localized tissue necrosis.
• The pain of the wound may last for a few days.
• Ptosis, Lymphadenopathy.
• In some victims – polyuria, renal failure and cardiac
electrophysiological dysfunction.
• Fatalities have not been reported.
Epidemiological features
Envenomation symptoms

30. • No benefit of antivenom therapy
even if severe local swelling is
present.
• Symptomatic treatment.
Treatment

31. Saw Scaled Viper
Echis carinatus
වැලි ප ොළඟා

32. Identifying
features
• Triangular head with no distinguishable
neck.
• Presence of two spiral lines on either
side of the body.
• A whitish brown bird footprint like mark
on top of the head.
• Grows to up to 2 feet.

33. Epidemiological features
• Habitat: Agricultural lands in the North and North
Central areas of Sri Lanka.Commonly found
underneath rocks and rocky surfaces during the
daytime.
Envenomation symptoms
• Swelling and reddening around the bite mark
• Neural effects
• Difficulty in opening and batting of eyes
• Internal bleeding
• Hematuria
• Reddish patches on the skin
• Bleeding gums
• Bloody stools
• Delayed blood clotting

34. Sri Lankan Krait
Bulgarus ceylonicus
මුදු කරවලා / දුනු කරවලා
கட்டு விரியன் / புடையன்

35. Identifying
features
• Upper body surface is glistening
black or brown.
• Has a shiny cylindrical body.
• Presence of 20-25 horizontal white
stripes till the edge of the tail.
• Presence of hexagonal scales on
the upper body surface along the
spine.
• Young ones have a white and black
striped belly.
• Has no proper neck.
• Hunts at night.

36. Epidemiological features
• Habitat: Mostly present in the dry zones
Envenomation symptoms
• Neural effects
• Difficulty in opening and batting eyes.
• Difficulty in breathing
• Weakness of limbs
• Unconsciousness
• Lower abdominal pain
• Difficulty to recognize the bite mark.

37. Treatment
for Snake
Bites
First Aid Measures
DO’s
• Reassurance
• Keep the patient warm and at rest
• Bandage and Immobilize the bitten limb with crepe
bandages and splint. (the full limb if possible) - to
retard the absorption of the venom
• Give a non-sedating, non-salicylate analgesic;
paracetamol is the best choice.
• Clean bite area with soap and water
• Remove any rings/bangles/shoes/tight clothing
because there will be edema.
• Take to the nearest hospital without delay
• If possible identify / take a picture of the snake.
• Tetanus toxoid
• Oxygen administration
The main goals of treatment:
• To prevent the spread of
venom in the body
• To reduce any
complications that might
arise due to the toxin

38. Treatment DONT’s
• Make incisions or suction around the bite site
• Raise the area of the bite site above the heart
• Apply a tourniquet
• Apply ice (Cryotherapy)
• Alcohol or caffeinated drinks should not be given
• Don’t use KMnO4 on the bite site and don’t give fruit or
juices rich in potassium ions

39. AVS
Therapy
• Antivenom should not be administered as a routine measure
since it can cause severe allergic reactions. It should only be
given when features of envenomation are present.
• Pulse rate, respiratory rate, BP, consciousness, temperature
and urine output should be monitored.
• Commence antivenom therapy immediately for bites of
cobra, Russell’s viper, krait and saw-scaled viper.
• There is no benefit in antivenom therapy for bites of the
Hump-nosed viper and the Green-pit viper.
• Dose: 100-200ml (10-20 ampoules) of Indian polyspecific
antivenom in 400ml of normal saline infused IV over one
hour.
• In viper bites the antivenom is repeated in 6 hours in a dose
of 100ml. for cobra and krait bites, first dose is sufficient.
• Observe the patient carefully for signs of anaphylaxis and
have adrenaline and chlorpheniramine ready.
• In a suspected venomous snake bite the patient should be
monitored for at least 24 hrs. for any signs of envenoming.

40. VENOMOUS
ARTHROPODS
Wasps,Giant Honey Bees, Bees,Centipedes, Scorpions, BlackWidow Spiders

41. Lesser Banded
Hornet
Vespa affinis affinis
පදබරා

42. Giant
Honey
BeeApis dorsata
බඹරා

43. Asiatic
Honey
BeeApis cerana
මී මැස්සා

44. Dwarf
Honey
BeeApis cerana
දඬුවැල් මැස්සා

45. Giant Ceylon
Centipede
Scolopendra maristans
ත්ෙෑයා
• Largest centipede found in Sri Lanka.
• A carnivore
• Uses its venom to immobilize its prey
and also as a defense strategy.
• Has a pair of primary fangs behind the
head with associated toxic glands.
• The venom contains serotonin and
histamine.
• Bite of the centipede is extremely
painful but it is not fatal.
• Some individuals get nausea,
sweating and lymph node
enlargement due to the presence of
toxin in blood.

46. Indian Red
Scorpion
Hottentotta tamulus
ඉන්දියානු රතු පගෝනුස්සා

47. Black
Widow
Spider
Latrodectus spp
දිවි මකුළුවා

48. Thank You!