Severe neurotoxic envenoming by Wall's Krait Bungarus walli in Bangladesh and Nepal

1
Severe neurotoxic envenoming by Wall's Krait
(Bungarus walli) in Bangladesh and Nepal 
Kuch U1, Faiz MA2, Sharma SK3, Basher
A4, Sayeduzzaman ABM4, Ghose A5, Harris JB6,
Warrell DA7

• 1 Biodiversity and Climate Research Centre,
  Frankfurt am Main, Germany
• 2 Directorate General of Health Services,
  Bangladesh
• 3 B.P. Koirala Institute of Health Sciences,
  Dharan, Nepal
• 4 Dhaka Medical College and Hospital, Bangladesh
• 5 Chittagong Medical College and Hospital,
  Bangladesh
• 6 Institute of Medical Toxicology, University of
  Newcastle upon Tyne, UK
• 7 University of Oxford, Nuffield Department of
  Clinical Medicine, Oxford, UK

2
"It is to be regretted that I am unable ... to
add to my original remarks on the effect of snake
poisons. Our complete ignorance as to whether
many of the snakes referred to are fatal ...
must have struck all readers of the previous
editions and it was hoped that many ... would
be induced to report cases coming under their
notice. To take examples, we have no single
record of symptoms of the poisoning of the banded
krait (Bungarus fasciatus), common as this snake
is in Assam and Burmah. Again, snakes so common
as the black kraits (B. lividus and niger) in
Assam, ... should furnish many records ....
Any information, however meagre, is worth
reporting, and may prove useful, and even a badly
mutilated snake is capable of identification in
competent hands." Wall, F. 1928. The Poisonous
Terrestrial Snakes of our British Indian
Dominions (including Ceylon) and How to
Recognize them. With Symptoms of Snake
Poisoning and Treatment. Fourth, revised
edition.
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Common Krait Bungarus caeruleus
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Approximate geographical distribution of Common
Kraits
Bungarus caeruleus
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"The natives call them Pyân, meaning, a drinker
.... The snake is said to suck a man's breath
while he sleeps, the result being that he dies at
sunrise with a swollen face, but no mark of a
bite on him. No one will sleep on the ground in
the desert at this time of the year September
through fear of the Pyân." Boulenger (1897) J.
Bombay Nat. Hist. Soc. 11, 7374
Bungarus sindanus
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Bungarus walli
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Wall's Krait Common Krait
17-19 dorsal scale rows
15 dorsal scale rows
Bungarus walli
Bungarus caeruleus
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Envenoming by Wall's Krait

• 18 cases of proven bites by kraits in Bangladesh
• 5 by B. caeruleus
• 1 by B. fasciatus
• 5 by B. niger
• 7 by B. walli
• 1 proven B. walli bite in SE Nepal

Dhaka Division
Dhaka Division
Chittagong Division
Khulna Division
Khulna Division
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Envenoming by Wall's Krait

• 6 cases with detailed histories
• 4 bitten at daytime, 2 at night
• All developed paralysis within 2-4 hr
• No response to Indian polyvalent antivenom
  (100-700 ml)
• No response to anticholinesterase
• All with generalised flaccid paralysis
  respiratory failure within 6-24 hr
• 5 recovered after 1-5 days of assisted
  ventilation
• 1 died 6.5 hr after the bite

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Case 1 Dhaka Division, Bangladesh (1)

• 30-yr-old farmer, bitten on foot at 1400 hr while
  at work

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Case 1 Dhaka Division, Bangladesh (2)

• 30-yr-old farmer, bitten on foot at 1400 hr while
  at work

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Case 6 Dhaka Division, Bangladesh (3)

• Ambulance to private clinic, then to Dhaka
  Medical College
• Loss of limb power, blurred vision, inability to
  open eyes or mouth during transport
• Admission 2.5 hr post-bite classical symptoms of
  neurotoxicity ankle clonus
• 100 ml antivenom anticholinesterase 5.45 hr
  after bite
• 7 hr after bite restless, respiratory distress,
  generalised flaccid paralysis
• Required mechanical ventilation for 5 days
• Ankle clonus persisting up to 4 days after bite

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Case 2 Dhaka Division, Bangladesh (1)

• 36-yr-old farmer, bitten at 0500 hr by snake
  entangled in net set up in fish pond
• 1.5 and 22.5 hr after bite treatment at houses
  of 2 different traditional healers
• 2.5 hr post-bite drowsiness, generalised
  weakness
• 4 hr after bite too weak to sit, brought to
  health care centre
• Referred to 1st hospital (no antivenom), then to
  2nd hospital

Bungarus walli
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Case 2 Dhaka Division, Bangladesh (2)

• Admission 9 hr post-bite at Dhaka Medical College
  Hospital severe neurotoxic envenoming with
  classical progressive generalised flaccid
  paralysis
• Fasciculations of chest and neck muscles

Wall's Krait (Bungarus walli) envenoming
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Case 2 Dhaka Division, Bangladesh (3)

• Neostigmine atropine four-hourly
• 100 ml polyvalent antivenom 9 hr after bite
• 17 hr after bite severe respiratory difficulty
  assisted ventilation
• 100 ml polyvalent antivenom 17.5 hr after bite
• Required 2 days of assisted ventilation
• Fasciculations of chest neck muscles lasted 2
  days
• Gradual recovery over 5 days

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Case 3 Nepal

• 29-yr-old male refugee, bitten in bed at 1930 hr
• 35 min later admitted to snakebite clinic
• Burning pain all over body, abdominal pain,
  vomiting
• Ptosis, blurred vision 50 ml antivenom
  anticholinesterase
• 1.5 hr after admission (2 hr post-bite) referred
  to hospital
• 650 ml antivenom in zonal hospital
• Died 6.5 hr after bite
• Accompanying persons vandalized ER of zonal
  hospital

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Conclusion

• More clinical studies of bites by accurately
  identified species are needed in South Asia
• It must not be assumed that the clinical syndrome
  of krait envenoming in much of this region is
  caused by Bungarus caeruleus alone
• There are 2 species of 17-scale-row kraits!
• They are widely distributed within the range of
  Bungarus caeruleus and regionally common
• Unusual clinical features warrant further
  investigation
• Their venoms should be considered for inclusion
  in antivenom production

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Acknowledgements

• Doctors and staff of
• - Dhaka Medical College and Hospital
• - Chittagong Medical College and Hospital
• - Nepal Red Cross Society Sub-chapter
  Damak-Jhapa
• - Khulna Medical College and Hospital