The term "Big Four" term is used in reference to 4 widespread and lethal snakes of India:
They are very popular and there is plenty of literature on them so you can find plenty of information about them.
Here I would like to center on an excellent recent article:
What the authors did was to review the literature on snakebites and found a clear pattern of snakes distribution, mainly neurotoxic envenomations are found in the North regions while hematotoxic envenomations are prevalent in the South of India. The authors propose some measures to increase awareness as well as treatment effectiveness between sanitary personnel and lay population.
This is a selection of what are for me the most relevant points. Please refer always to the original article:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5113082/
The North-South divide in snake bite envenomation in India
Vivek Chauhan, Sumar Thakur
Dr. RPGMC, Kangra, Tanda, Himachal Pradesh, India
J. Emerg. Trauma Shock. 2016 Oct-Dec; 9(4): 151-154
(This is an open access article).
Cursive are mine.
ABSTRACT:
Snake bite envenomations are common in rural areas and the incidence peaks during monsoons in India. Prominent venomous species have been traditionally labeled as the "big four" that includes Cobra, Krait, Russel's viper and Saw scaled viper. Systematic attempts for identification and classification of prevalent snakes in various states of India are missing till now and there is no concrete data on this aspect. The published literature however shows that some species of snakes are more prevalent in a particular region that the other parts of India e.g. Saw scaled vipers in Rajasthan.
We reviewed the published literature from various parts of India and found that there is a North-South divide in the snake bite profile from India.
Neurotoxic envenomations are significantly higher in North India compared to South India, where Hematotoxic envenomations are prevalent.
Russel's viper causes local necrosis, gangrene and compartment syndrome. These manifestations have never been reported in North Indian snake bite profile in the published literature. Early morning neuroparalysis caused by Krait is a common problem in North India leading to high mortality after snake bite.
This review presents supporting evidence for the North-South divide and proposes a way forward in formulation and revision of guidelines for snake bite in India.
INTRODUCTION:
The Russell's viper is the one that can cause severe local necrosis, gangrene and compartment syndrome, which has rarely been reported from N-I.
Neurotoxicity in N-I is caused mainly by Krait that bites indoors during night and mostly while the victim is asleep. The bite is painless, so the patient usually does not awake at the time of bite. In the morning, many of the victims are found dead, and others are paralyzed.
Here I would like to center on an excellent recent article:
What the authors did was to review the literature on snakebites and found a clear pattern of snakes distribution, mainly neurotoxic envenomations are found in the North regions while hematotoxic envenomations are prevalent in the South of India. The authors propose some measures to increase awareness as well as treatment effectiveness between sanitary personnel and lay population.
This is a selection of what are for me the most relevant points. Please refer always to the original article:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5113082/
The North-South divide in snake bite envenomation in India
Vivek Chauhan, Sumar Thakur
Dr. RPGMC, Kangra, Tanda, Himachal Pradesh, India
J. Emerg. Trauma Shock. 2016 Oct-Dec; 9(4): 151-154
(This is an open access article).
Cursive are mine.
ABSTRACT:
We reviewed the published literature from various parts of India and found that there is a North-South divide in the snake bite profile from India.
Neurotoxic envenomations are significantly higher in North India compared to South India, where Hematotoxic envenomations are prevalent.
Russel's viper causes local necrosis, gangrene and compartment syndrome. These manifestations have never been reported in North Indian snake bite profile in the published literature. Early morning neuroparalysis caused by Krait is a common problem in North India leading to high mortality after snake bite.
This review presents supporting evidence for the North-South divide and proposes a way forward in formulation and revision of guidelines for snake bite in India.
INTRODUCTION:
On review of literature available for India, we saw a North-South divide in the presentation of venomous snake bites in India that has not been discussed till now by researchers, and the guidelines are also silent about it.
Russell's viper is the most poisonous snake among "the big four" and is ubiquitous in South India (S-I), but is missing completely from all of North India (N-I) reports.
N-I snakes predominantly cause neurotoxicity in 70.95% of cases (877 envenomations).
S-I snakes predominantly cause hemotoxicity or nephrotoxicity in 83.59% (1965 envenomations). This trend becomes apparent as we move Southward from Delhi early as Maharashtra, which has thus been included by us in S-I region.
- The North Indian profile is neurotoxicity predominant (Krait)
- The South India profile is hemo/nephrotoxicity predominant (Russell's and saw-scaled vipers).
Up to 30% of snake bites in NI are also cause by vipers, mostly saw-scaled or Himalayan pit vipers that cause mild hemotoxicity and in some cases mild nephropathy but ralely requiring dialysis.
We need separate means and resources to tackle with two totally different profiles. All health-care personnel irrespective of their place of work must be trained in the airway and ventilation management. This alone can save many lives.
DEADLY RUSSELL'S VIPER IN SOUTH:
Physicians in S-I have a nightmare treating the complicated Russell's viper envenomation that can cause severe local necrosis, nephrotoxicity, hemotoxiity and neurotoxicity, all four in the same patient!!! Such presentation in unheard in the North.
The policymakers need to be aware of this fact so that they can establish more Intensive Care Unit and hemodialysis facilities for the management of complicated Russell's viper envenomations.
A maximum of 30 vials of anti-snake venom (ASV) is recommended for Russell's viper envenomation. Ten vials repeated 6 hourly till 30 vials total if whole blood clotting time remains >20 min. The symptoms usually reverse within few hours of ASV. Some patients develop severe nephrotoxicity despite early ASV. The neuroparalysis due to pre-synaptic toxin is unresponsive to ASV or neostigmine, and it takes 2-4 days for the reversal of paralysis.
The patients need ventilatory support to survive.
Russell's viper bites cause severe local necrosis, swelling, bleb formation, and even compartment syndrome. Good wound care and monitoring are required for compartment syndrome, and the surgical opening of fascial planes for pressure release may be needed in some cases.
Cardiotoxicity, arrhytmias and autonomic dysfunction can also occur with Russell's viper bites.
Health-care personnel and lay persons need to be educated through mass communication media regarding the prevalent medically important snakes in their area and their early manifestations so that they can seek timely treatment.
NOTORIOUS KRAIT IN NORTH:
In the absence of the snake sighting or fang marks over the body, the diagnosis of snake bite is missed until the patients reaches a competent doctor who has knowledge of the early morning neuroparalysis caused by krait bite.
Ninety five percent of the Krait bites are documented within June to August months (Monsoon season).
People die of respiratory paralysis.
 |
| Laryngeal mask airway |
There is a need for mass awareness specifically for early morning neuroparalysis (even abdominal pain as seen many time on Krait bites) specially during the monsoon months.
We need to provide an early airway and breathing support for these people.
All health-care staff needs to be trained in the use of laryngeal airway devices and the use of AMBU to ventilate a paralyzed victim till he can be shifted to the hospital. Laryngeal airway can be put blindly to secure the airway by staff nurses, health workers and technicians after a hands-on training of few hours.
The cost of laryngeal airway device is less than a single vial of ASV. Still, nowhere in N-I, we will find trained health staff and availability of laryngeal airway in the subcenters, primary health centers, and even in community health-care centers where it is badly needed.
The use of laryngeal airways or AMBU will save more lives than any amount of ASV pumped into the system.
Krait venom is not reversible with the use of neostigmine and takes 2-4 days to reverse. The patient needs ventilatory support for 2-4 days and most patients die due to the lack of ventilatory facilities even after reaching hospitals.
Even the ASV does not reverse the neuroparalysis, which is due to presynaptic failure and it takes 2-4 days to regenerate presynaptic apparatus.
ASV should be given to all neurotoxic envenomations in doses up to 20 vials maximum. The first dose for Krait bite is 10 vials and repeat doses are given if the symptoms are progressive after 1-2h. This regimen is as per the national snakebite management protocol.
COBRA BITES ARE INFREQUENT THROUGHOUT INDIA:
Cobra is present all over India, and we found that of all venomous bites, cobra is responsible for only 5-10% all over India. This tells us that encounter with cobra is infrequent, and it does not stay as close to humans as Russell's viper and Krait.
The differentiating feature of cobra from krait is the local pain, necrosis and swelling at the site of bite which is seen in cobra and never in krait bites.
Neostigmine is another way of differentiating as cobra venom is post-synaptic and can be reversed using 1.5-2mg of neostigmine given intramuscular (IM) with 0.6 mg of atropine IM. The reversal is seen within minutes, and it can be repeated 0.5 mg of neostigmine IM every 30 min. for up to 8h. with 0.6 mg atropine by infusion.
If the patient shows signs of bleeding or nephrotoxicity, we should discard a Russell's viper envenomation. Russell's venom is unresponsive to neostigmine, and it should no be repeated if there is no improvement in ptosis after the first dose within an hour.
Cobra bite releases high volumes of venom, so ASV required is up to 20 vials. The first dose given is 10 vials and repeated after 1-2h for up to 20 vials maximum if the symptoms are showing a progression over time.
SAW-SCALED VIPER:
It is prevalent all over India.
The saw-scaled viper bites are more common culprits in hemo-nephrotoxic envenomations in North India than is South. Of all envenomations in North, 30% are hemotoxic. These bites are mostly caused by the saw-scaled viper.
The patients presents with local swelling and mild bleeding manifestations. The whole blood clotting time is >20 min and the patient may be in hypotension.
These patients develop mild acute kidney injury in most cases, rarely requiring dialysis.
Mortality due to saw-scaled viper is rare and complications are acute kidney injury requiring hemodialysis. The ASV is effective against most of the cases in North India.
COBRA BITES ARE INFREQUENT THROUGHOUT INDIA:
The differentiating feature of cobra from krait is the local pain, necrosis and swelling at the site of bite which is seen in cobra and never in krait bites.
Neostigmine is another way of differentiating as cobra venom is post-synaptic and can be reversed using 1.5-2mg of neostigmine given intramuscular (IM) with 0.6 mg of atropine IM. The reversal is seen within minutes, and it can be repeated 0.5 mg of neostigmine IM every 30 min. for up to 8h. with 0.6 mg atropine by infusion.
If the patient shows signs of bleeding or nephrotoxicity, we should discard a Russell's viper envenomation. Russell's venom is unresponsive to neostigmine, and it should no be repeated if there is no improvement in ptosis after the first dose within an hour.
Cobra bite releases high volumes of venom, so ASV required is up to 20 vials. The first dose given is 10 vials and repeated after 1-2h for up to 20 vials maximum if the symptoms are showing a progression over time.
SAW-SCALED VIPER:
The saw-scaled viper bites are more common culprits in hemo-nephrotoxic envenomations in North India than is South. Of all envenomations in North, 30% are hemotoxic. These bites are mostly caused by the saw-scaled viper.
The patients presents with local swelling and mild bleeding manifestations. The whole blood clotting time is >20 min and the patient may be in hypotension.
These patients develop mild acute kidney injury in most cases, rarely requiring dialysis.
Mortality due to saw-scaled viper is rare and complications are acute kidney injury requiring hemodialysis. The ASV is effective against most of the cases in North India.
Green pit viper and Hump-nosed pit viper:
The first has been described as hemotoxic in North-areas while the second is reported and hemo and nephrotoxic in south.
THE CURRENT GUIDELINES AND THE WAY FORWARD:
The National Snakebite Management Protocol was released by the Director General of Health Services, Ministry of Health and Family Welfare, India, in 2009.
The World Health Organization regional office for South East Asia also released guidelines for the management of snake bites in 2010.
These are the latest updated resources* for the identification and management of snake bites in India.
The ASV available in India is raised in horses against "the big four" only. However, there are other medically important species naw being frequently reported from various parts on India and unresponsive to this polyvalent ASV:
Hypnale Hypnale (hump-nosed pit viper)
Echis carinatus sochureki (saw-scaled viper, Rajasthan)
Trimeresurus malabaricus (Malabar pit viper, Karnataka).
Green pit viper (Himachal Pradesh
between others.
Seems as the authors consider Cobra and Krait as a whole. ASV is prepared specifically from Naja Naja (spectacle Cobra) and Bungarus Caeruleus (Common Krait) species. Other species of these families that are also common in some territories, like Naja Kaouthia (monocle Cobra) in Norht-East are not fully responsive to the ASV.
This review brings into focus the updated situation of variable venomous snake bite profile in various parts of India based on the published literature.
There may be other species causing medically important envenomations but due to the lack of evidence, they have not been included.
* This article was accepted for publication in August 2016. Later on, by the end of 2016 a new Guidelines for the management of snakebites were published.
This is the link:
The first has been described as hemotoxic in North-areas while the second is reported and hemo and nephrotoxic in south.
THE CURRENT GUIDELINES AND THE WAY FORWARD:
The National Snakebite Management Protocol was released by the Director General of Health Services, Ministry of Health and Family Welfare, India, in 2009.
The World Health Organization regional office for South East Asia also released guidelines for the management of snake bites in 2010.
These are the latest updated resources* for the identification and management of snake bites in India.
The ASV available in India is raised in horses against "the big four" only. However, there are other medically important species naw being frequently reported from various parts on India and unresponsive to this polyvalent ASV:
Hypnale Hypnale (hump-nosed pit viper)
Echis carinatus sochureki (saw-scaled viper, Rajasthan)
Trimeresurus malabaricus (Malabar pit viper, Karnataka).
Green pit viper (Himachal Pradesh
between others.
Seems as the authors consider Cobra and Krait as a whole. ASV is prepared specifically from Naja Naja (spectacle Cobra) and Bungarus Caeruleus (Common Krait) species. Other species of these families that are also common in some territories, like Naja Kaouthia (monocle Cobra) in Norht-East are not fully responsive to the ASV.
This review brings into focus the updated situation of variable venomous snake bite profile in various parts of India based on the published literature.
There may be other species causing medically important envenomations but due to the lack of evidence, they have not been included.
- We suggest a nationwide registry of snakebites involving medical colleges so that we know the profile of medically important species and their variations from North to South and East to West.
- And effort should be made to differentiate the type of viper involved when hemonephrotoxic manifestation is seen.
- Mass awareness of locally prevalent snakes, their manifestations, first aid do's and don'ts and the centers with the availability of ASV is very important in dealing effectively with the menace of snake bites in India.
- We may find poor response to ASV against even "the big four" due to regional variability in species (and even same specie) which needs to be taken care of.
- The current ASB is produced from snakes found in a very small area in South India, and these may not be very effective against snakes found in other regions.
- All Asha workers and ambulance technicians should be trained in first aid and early management of snake bite. They should become the rescue agents in the place of the tantriks and mantriks who delay the treatment by fostering a false belied in the minds of the people that they can do miracles.
* This article was accepted for publication in August 2016. Later on, by the end of 2016 a new Guidelines for the management of snakebites were published.
This is the link:
ॐ लोकाः समस्ताः सुखिनो भवन्तु ॥
Om Lokah Samasthah Sukhino Bhavantu
May all beings everywhere be happy and peaceful.
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