Overview
India has many snake species, and only a small number of them are venomous. Bites by non-venomous snakes are common, and even a venomous snake sometimes bites without injecting venom, which is called a dry bite. None of this can be judged at the scene, so every bite is handled as an emergency.
The venomous snakes that matter most in rural Maharashtra are the cobra, the common krait, Russell's viper and the saw-scaled viper. Antivenom is the only specific treatment, it is given in hospital, and it works best when it is given early.
Symptoms
Fang marks may be obvious, or there may be nothing to see. Cobra and krait venom mainly affects the nerves, and viper venom mainly affects the blood and the bitten limb.
- Nerve effects: drooping eyelids first, then double vision, slurred or quiet speech, difficulty swallowing and breathlessness
- Krait bites often happen at night on the floor and show up as severe tummy pain and vomiting on waking, before the weakness starts
- Bleeding effects: bleeding gums, nosebleeds, bruising, blood in vomit, stool or urine, and oozing from the bite
- Local effects: pain, spreading swelling, blistering and, later, dead tissue
- Kidney effects: little or no urine, or dark red or brown urine
- Fright alone can cause a racing heart, sweating and tingling, even when no venom was injected
When to see a doctor
See a doctor again in the days after discharge for rash, fever, joint pain or itching about five to ten days after antivenom, for a wound that becomes red, hot or smelly, or for weakness in the limb that is not improving.
Causes
Snakes bite in self-defence, when they are trodden on, handled, cornered or disturbed. Most bites are accidents during ordinary work and sleep, not attacks.
Bites rise in the monsoon and after floods, when snakes are driven out of their holes, and many happen during ploughing, weeding and harvesting, while walking in the dark, or while sleeping on the floor.
Risk factors
- Farming and field work, especially barefoot or in sandals
- Sleeping on the floor rather than on a cot
- Walking outdoors at night without a torch
- Rubbish heaps, firewood stacks, grain stores and rat holes near the house
- The rainy season and the weeks after a flood
- Handling, catching or trying to kill snakes
- Living far from a hospital that stocks antivenom
Complications
Venom can paralyse the breathing muscles, stop the blood from clotting, injure the kidneys or destroy tissue around the bite. Severe bleeding, kidney failure and respiratory failure are the usual causes of death.
Later problems include a limb left weak or scarred, amputation after severe tissue damage, and serum sickness, an allergic reaction with rash, fever and joint pain that appears about five to ten days after antivenom.
Prevention
- Sleep on a cot with a tucked-in mosquito net rather than on the floor
- Wear shoes or boots and full-length trousers in the fields, and shake out footwear before wearing it
- Carry a torch after dark, and never walk where you cannot see the ground
- Use a stick to disturb grass, leaves, firewood and cut fodder before picking them up
- Do not put a hand or foot into holes, crevices or any place you cannot see
- Clear rubbish, building material and long grass near the house, close rat holes, store grain in rat-proof containers and keep poultry out of the house
- Leave snakes alone, and never try to catch, corner or kill one, including one that looks dead
Diagnosis
The doctor asks what happened and when, examines the bite and looks for signs that venom has acted: drooping eyelids, weakness, bleeding, spreading swelling and urine output.
A simple bedside test of how long the blood takes to clot is repeated over the first hours, along with blood counts, kidney tests and urine tests. Everyone bitten is admitted and watched for at least twenty-four hours, because effects can be delayed.
Treatment
First aid, while transport is arranged:
- Move away from the snake and keep the person calm and lying still
- Remove rings, bangles, a watch, anklets, footwear and tight clothing from the bitten side
- Splint the bitten limb so it cannot move, without tying anything tight
- Lay a drowsy person on their left side so the airway stays clear, and give nothing to eat or drink
- Carry them to the vehicle. They must not walk or drive themselves
In hospital, antivenom is given into a vein once there is evidence of envenoming, with adrenaline kept ready for a reaction. Medicines that improve nerve transmission help some nerve-paralysis bites, a ventilator supports breathing if the muscles fail, and is used for kidney failure. Tetanus cover, pain relief, for infection and surgery for dead tissue are added as needed, and physiotherapy helps the limb recover.
Myths and facts
Things people often say about this. Open each one to see what is true.
Myth“Cut the bite open and suck the venom out.”What is true?
Fact
Cutting, pricking, tattooing and sucking do not remove venom. They introduce infection, increase bleeding and can make the venom spread faster, and they waste the time in which antivenom would have worked. Leave the wound alone.
Myth“Tie a tight band above the bite so the poison cannot travel.”What is true?
Fact
A tight tourniquet can cut off the blood supply and cost the person the limb. National guidance is clear that immobilising the limb matters far more than tying it: splint it as you would a fracture, firmly enough to stop movement but never tight enough to stop the blood flow.
Myth“Put ice, a black stone, herbs or chemicals on the wound, or give an electric shock.”What is true?
Fact
Black stones, ice packs, topical chemicals and herbs, and electric shocks are all described by the World Health Organization as useless or frankly dangerous. The wound should not even be washed, because washing and rubbing can increase the absorption of venom.
Myth“Go to the healer in the village first, and to hospital only if things get worse.”What is true?
Fact
Traditional remedies have no proven benefit in snake bite, and the delay is what kills. Many deaths in India happen because antivenom was given too late. Go straight to a hospital that has antivenom, and let someone else drive.
Myth“There are no fang marks and no pain, so there is nothing to worry about.”What is true?
Fact
A krait may leave no visible mark at all, and its bite often shows up hours later as severe tummy pain on waking, then drooping eyelids and weakness. Swelling and bleeding from a viper bite can also be delayed. Everyone who has been bitten is watched in hospital for a full day.
Questions to ask your doctor
Tick the ones you want answered and take them with you.
Common questions
Should we kill the snake and take it along so the right antivenom is given?
No. Trying to catch or kill a snake risks a second bite, and even a dead snake can inject venom through its fangs. The antivenom used in India covers the common venomous species together, so identifying the snake is not needed before treatment. Note the colour and shape if you saw it clearly, and go.
The person feels completely fine. Do we still need to go to hospital?
Yes. Krait venom can take hours to show itself, and viper effects can also be delayed. Feeling well in the first hour does not mean no venom was injected. The safe course is to be admitted and observed for a full day, and most people who were not envenomed go home after that.
Is a tight crepe bandage the same as a tourniquet?
They are not the same, but this is easy to get wrong. A tourniquet is tight enough to cut off blood flow and can destroy the limb. Pressure immobilisation with a wide bandage over a splinted limb is a specific technique for certain nerve-paralysing bites and is meant for trained hands. For a family member at home, the safe instruction is to splint the limb and go.
What should we tell the hospital when we arrive?
The time of the bite, where on the body it happened, what the person was doing, whether they slept on the floor the night before, anything already applied to the wound or given by mouth, any long-term illnesses and medicines, and every new symptom that appeared on the way.