Bangladesh once had 28 species of venomous snakes, but today mainly five are found: the cobra (gokhra), the krait (kalkeute), the Russell's viper (chandrabora), the green pit viper and sea snakes. Cobras and kraits are the most common; green pit vipers are found in the Chittagong Hill Tracts, sea snakes in the sea, and for some years Russell's vipers have been found in and around Rajshahi.

Recently Russell's vipers have been found in many districts besides Rajshahi. A few years ago the snake was hardly present in the country, and there is still no scientific explanation for why it has returned and spread. But a lot of false information about it is being spread on social media, and people are panicking. That is why I am writing this.

Why do snakes bite? Many people rest under trees in hot weather, and snakes often pass over their bodies without doing anything, because snakes do not see; they hunt using sound waves. Snakes usually live on fish, insects, rats, chicks, eggs and lizards, and use their venom to kill these animals. A snake bites in self-defence when it is provoked or feels threatened. It does not bite anyone on its own.

Does the Russell's viper chase people? No snake can chase anyone. The claim that the Russell's viper rushes at people and bites them on sight is completely false.

Is the Russell's viper the most venomous snake in the world? No. There are far more venomous and aggressive snakes, such as the inland taipan and the black mamba.

Is death certain after a Russell's viper bite? This is also false. The venom of our common venomous snakes, such as cobras and kraits, is similar in type to that of the Russell's viper, but the viper's venom contains an element that stops blood from clotting. Bleeding can therefore start anywhere in the body and, because the blood does not clot, it can be heavy. But there is modern treatment for the venom of the Russell's viper and our other venomous snakes. Rajshahi Medical College Hospital has treated the largest number of Russell's viper bite patients so far, and most have recovered.

If the bite is on the hand, the hand should be bound so that it cannot be moved; this slows the spread of venom. If the bite is on the leg, the person must not walk.

How long after a bite do symptoms of poisoning appear? That depends on how much venom was injected, how long before the bite the snake had eaten, and how much the bitten hand or leg is moved. Moving the bitten part spreads the venom through the body faster. Symptoms of poisoning can appear within 24 hours of a venomous bite. If none appear in that time, the patient is considered no longer at risk.

What is the main cause of death among snakebite patients? Lack of awareness. Last year in Chapainawabganj, a snake bit two people sleeping on the floor of a madrasa boarding house at night. They first went to an ojha (traditional healer), who said there was no problem, then to a second and a third ojha. After losing seven hours this way, they set out for hospital only when they began to have breathing difficulty. One died on the way and the other after reaching hospital. Once poisoning begins after a venomous bite, antivenom must be given as quickly as possible. The longer the delay, the lower the chance of recovery.

Why do some patients recover after an ojha's incantations? Most snakes in our country are non-venomous. People bitten by non-venomous snakes, or by venomous snakes that did not inject venom, need no treatment and recover anyway, but the credit goes to the kabiraj's incantations.

Those who die of snakebite are usually of working age and often the family's only earner. A little awareness can prevent these deaths.

• While fishing.
• In the rainy season, when water is everywhere, snakes shelter indoors in dry places such as where firewood is stored, in beds, kitchens, clothes racks and haystacks. Going into these places in the dark or silently carries a high risk of being bitten.
• While walking on roads in the dark at night, as snakes mostly move about at night.
• Snakes come into chicken or duck houses to eat eggs or chicks, and bite anyone who goes in.
• While sleeping on a veranda or in the yard in hot weather.

• Do not panic. There are few venomous snakes in our country, and even after a venomous bite the chance of poisoning is 50 per cent.
• Do not move the bitten part. Do not tie a tight knot, as this can stop blood circulation, but it may be bound loosely with a thin gamchha or a torn strip of sari. Moving the bitten place spreads the venom faster. However, a Russell's viper bite must not be bound in any way, as this can seriously harm the patient.
• Do not take the patient to an ojha, do not perform incantations and do not use kabiraji treatment. Do not cut the bite site with a blade.
• Take the patient to hospital as quickly as possible. On the way, check by mobile phone or any other means whether that hospital can give antivenom, and go to one that can, so that no time is lost and the patient is treated quickly.
• Observe the patient for 24 hours from the time of the bite, as poisoning usually occurs within that period. If there are no signs of poisoning in that time, there is nothing more to fear.

If poisoning occurs after a snakebite and antivenom is not given, death is certain. The good news is that the government has supplied antivenom to all upazila health hospitals in the country and taken the necessary steps to treat snakebite at upazila level.

Leading this work are Professor Dr Md Robed Amin, line director of the non-communicable disease control programme of the health department, and Professor Dr Md Abul Faiz, former Director General of Health. When a snakebite patient is admitted to any hospital in the country, snakebite experts from across the country give treatment advice and suggestions through a WhatsApp group. This is ensuring treatment for snakebite patients even at the grassroots.

There is no need to worry separately about the Russell's viper, as it is like the other venomous snakes and patients can recover with treatment. So when someone is bitten, the first job of the patient and relatives is to go quickly to the nearest hospital. This one piece of awareness can save many snakebite patients, and it is important that we all understand it.

The writer is an associate professor in the medicine department of Prime Medical College and founder of Daktarkhana (GP Centre).

Source: Jagonews24. First published in Bengali on The Agro News.