Bungarus candidus ( Malayan Krait )
Original photo copyright © Dr Julian White
Family:
Elapidae
Subfamily:
Elapinae
Genus:
Bungarus
Species:
candidus
Common Names:
Malayan Krait , Common Krait , Blue Krait , Javan Krait
Local Names:
Ular Katang Tebu , Ular Weling , Oraj Weling
Region :
Southeast Asia
Countries :
Cambodia, Indonesia, Laos, Malaysia, Myanmar, Singapore, Thailand,
Vietnam
Taxonomy and Biology
Adult Length:
0.80 m
General Shape:
Medium in length, slender, cylindrical bodied snake with a short tail ending in
a sharp tip. Can grow to a maximum of about 1.60 metres. Head is flat and
slightly distinct from neck. Eyes are small in size and black with a barely
visible, round pupils. Nostrils are large. Dorsal scales are smooth and glossy
with the vertebral row enlarged and hexagonal. Dorsal scale count 15 ( 17 ) -
15 - 15.
Habitat:
Lowland hilly primary and secondary wet forest at elevations usually up to
about 1600 metres. Rarely found in human habitations.
Habits:
Nocturnal and terrestrial snake with an inoffensive disposition. When disturbed
it coils loosely and hides its head beneath its body. Reluctant to bite except
upon persistent provocation.
Prey:
Feeds mainly on snakes, but will occasionally feed on small mammals, lizards
and frogs.
Bungarus candidus ( Malayan Krait ) Original photo copyright © Dr Wolfgang Wuster
Venom
General: Venom Neurotoxins
|
Pre- & Post-synaptic neurotoxins
|
General: Venom Myotoxins
|
Not present
|
General: Venom Procoagulants
|
Not present
|
General: Venom Anticoagulants
|
Not present
|
General: Venom Haemorrhagins
|
Not present
|
General: Venom Nephrotoxins
|
Not present
|
General: Venom Cardiotoxins
|
Not present
|
General: Venom Necrotoxins
|
Not present
|
General: Venom Other
|
Not present or not significant
|
Clinical Effects
General: Dangerousness
|
Severe envenoming likely, high lethality potential
|
General: Rate of Envenoming
|
Unknown but likely to be high
|
General: Untreated Lethality Rate
|
60-70%
|
General: Local Effects
|
None or minimal
|
General: Local Necrosis
|
Not likely to occur
|
General: General Systemic Effects
|
Variable non-specific effects which may include headache,
nausea, vomiting, abdominal pain, diarrhoea, dizziness, collapse or
convulsions
|
General: Neurotoxic Paralysis
|
Very common, flaccid paralysis is major clinical effect
|
General: Myotoxicity
|
Not likely to occur
|
General: Coagulopathy & Haemorrhages
|
Unlikely to occur
|
General: Renal Damage
|
Unlikely to occur
|
General: Cardiotoxicity
|
Unlikely to occur
|
General: Other
|
Not likely to occur
|
First Aid
Description: First aid for bites by Elapid snakes which do
not cause significant injury at the bite site, but which may have the potential
to cause significant general (systemic) effects, such as paralysis, muscle
damage, or bleeding.
Details
1. After ensuring the patient and onlookers have moved out
of range of further strikes by the snake, the bitten person should be reassured
and persuaded to lie down and remain still. Many will be terrified, fearing
sudden death and, in this mood, they may behave irrationally or even
hysterically.
The basis
for reassurance is the fact that many venomous bites do not result in envenoming,
the relatively slow progression to severe envenoming (hours following elapid
bites, days following viper bites) and the effectiveness of modern medical
treatment.
2. The
bite wound should not be tampered with in any way. Wiping it once with a damp
cloth to remove surface venom is unlikely to do much harm (or good) but the
wound must not be massaged.
3. All
rings or other jewellery on the bitten limb, especially on fingers, should be
removed, as they may act as tourniquets if oedema develops.
4. If the
bite is on a limb, a broad bandage (even torn strips of clothing or pantyhose)
should be applied over the bitten area at moderate pressure (as for a sprain;
not so tight circulation is impaired), then extended to cover as much of the
bitten limb as possible, including fingers or toes, going over the top of
clothing rather than risking excessive limb movement by removing clothing. The
bitten limb should then be immobilised as effectively as possible using an
extemporised splint or sling.
5. If
there is any impairment of vital functions, such as problems with respiration,
airway, circulation, heart function, these must be supported as a priority. In
particular, for bites causing flaccid paralysis, including respiratory
paralysis, both airway and respiration may be impaired, requiring urgent and
prolonged treatment, which may include the mouth to mask (mouth to mouth)
technique of expired air transfer. Seek urgent medical attention.
6. Do not
use Tourniquets, cut, suck or scarify the wound or apply chemicals or electric
shock.
7. Avoid
peroral intake, absolutely no alcohol. No sedatives outside hospital. If there
will be considerable delay before reaching medical aid, measured in several
hours to days, then give clear fluids by mouth to prevent dehydration.
8. If the
offending snake has been killed it should be brought with the patient for
identification (only relevant in areas where there are more than one naturally
occurring venomous snake species), but be careful to avoid touching the head,
as even a dead snake can envenom. No attempt should be made to pursue the snake
into the undergrowth as this will risk further bites.
9. The
snakebite victim should be transported as quickly and as passively as possible
to the nearest place where they can be seen by a medically-trained person
(health station, dispensary, clinic or hospital). The bitten limb must not be
exercised as muscular contraction will promote systemic absorption of venom. If
no motor vehicle or boat is available, the patient can be carried on a
stretcher or hurdle, on the pillion or crossbar of a bicycle or on someone's
back.
10. Most
traditional, and many of the more recently fashionable, first aid measures are
useless and potentially dangerous. These include local cauterization, incision,
excision, amputation, suction by mouth, vacuum pump or syringe, combined
incision and suction ("venom-ex" apparatus), injection or
instillation of compounds such as potassium permanganate, phenol (carbolic
soap) and trypsin, application of electric shocks or ice (cryotherapy), use of
traditional herbal, folk and other remedies including the ingestion of emetic
plant products and parts of the snake, multiple incisions, tattooing and so on.
Treatment
Treatment Summary
Krait
bites can cause moderate to severe flaccid paralysis, respiratory failure,
requiring intubation & ventilation in severe cases. Antivenom available for
major species, may prevent worsening of paralysis, but may not reverse
established paralysis.
Key Diagnostic Features
Minimal
to mild local reaction + flaccid paralysis
General Approach to Management
All cases
should be treated as urgent & potentially lethal. Rapid assessment &
commencement of treatment including appropriate antivenom (if indicated &
available) is mandatory. Admit all cases.
Antivenom
Therapy
Only
antivenoms available are for related species, but should be used for
significant envenoming
Antivenoms
1.
Antivenom Code: SAsTRC04
Antivenom
Name: Banded Krait Antivenin
Manufacturer:
Science Division, Thai Red Cross Society
Phone:
++66-2-252-0161 (up to 0164)
Address:
Queen Saovabha Memorial Institute
1871 Rama
IV Road
Pathumwan
Bangkok
10330
Country:
Thailand
2.
Antivenom Code: SAsVRU03
Antivenom
Name: Bungarus candidus Antivenom
Manufacturer:
Venom Research Unit
Address:
University of Medicine and Pharmacy
Ho Chi
Minh City
217 An
Duong Vuong Q5
Country:
Vietnam
Source: Clinical Toxinology Resources
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