SUBJECT :A volunteer driven project maps snake behaviour in urban areas from over 4,000 sightings, and finds that they pose a higher risk at dusk 

Kochi, June 30, 2018: If you are taking a stroll in the countryside or even in your own backyard at dusk, watch what you are stepping on. That is because; between 4 p.m. and 9 p.m. there is a higher possibility of encountering snakes. The six hours between midnight and 6 a.m. are the safest with the lowest probability of running into snakes, say herpetologists.

This insight into the behaviour of the reptiles was mined from a database of over 4,000 snake sightings generated by Big4 Mapping, a citizen science project.

The analysis of data was presented at a recent conference on the theme, ‘Snakebite: from science to society,’ held at Leiden, Netherlands.

A scientific understanding of the behaviour of deadly snakes, the places where one is likely to encounter them, the risky hours and management of snake-bite victims are important as annually 25,000 lives are lost to snake bites in the country (The 2011 Million Deaths study estimates this number to be about 46,000 annually).

Armed with smartphones and moving across different terrain, including thickly populated urban areas, abandoned buildings and even inside homes, hundreds of volunteers have generated a unique database of sightings of Common Krait (Bungarus caeruleus), Spectacled Cobra (Naja naja), Russell’s Viper (Daboia russelii) and Saw-scaled Viper (Echis carinatus).

The four species were shortlisted as they accounted for most of the fatal bites.

Lethal bite: Common krait (in picture), spectacled cobra and saw-scaled viper are among the most poisonous snakes in the country.   | Photo Credit: Special Arrangement

Risky hours

Snake experts are now mining the database to identify the risky hours when the possibility of bites is higher. Most encounters occur during the evening hours and just outside houses or buildings as snakes look for food.

The citizen science project was helped by over 1,200 volunteers and it mapped 4,000 sightings of the Big-4 venomous snakes, which are considered responsible for most human deaths, said Jose Louies, a member of the Viper Specialist Group of the International Union for Conservation of Nature.

Most volunteers were snake-rescuers who get distress calls in their respective areas.

Each incident is photographed live and the GPS location is mapped through the mobile application, developed by a start-up run by engineering students from Kerala, said Mr. Louies, who is also the founder of the website indiansnakes.org.

The snake-mapping project aims to understand the regional distribution of venomous snakes in India. After one year, details of habitat and activity patterns of these medically important snakes has started emerging, he said.

Around 70% of the snakes that were sighted during the last one year were common or spectacled cobra. While Russell’s vipers accounted for 20% of sightings and common kraits 9%, there were only 92 sightings of saw-scaled vipers, that is, just 2%.

The study mostly looked at developed and developing areas. Agricultural landscapes, which are a hotspot for snake bites, could not be covered.

Efforts are on to map more snakes, rescues, snake bites, hospitals, treatment facilities and anti-venom stockists on a single platform, to ensure that every emergency related to snakes and snake bites is well managed and centrally monitored, he explained.

Snake sightings go up significantly during monsoon, as prey availability increases. As their burrows get flooded, rodents and other prey move out looking for safe shelter, and snakes make use of this opportunity.

Snakes enter dwelling units in search of warm and dry places during the monsoon, according to experts.

Lethal bite: Common krait, spectacled cobra (in picture) and saw-scaled viper (in picture) are among the most poisonous snakes in the country.   | Photo Credit: Special Arrangement

Bite management

Dr. V.V. Pillay, chief, Poison Control Centre of the Amrita Institute of Medical Sciences and Research, Kerala, listed wrong beliefs about treatment of victims, inadequate stock of anti-venom in government hospitals and poor training of physicians in the correct management of snakebite victims as the main hurdles to providing medical support.

Under the existing scheme, the Union Health Ministry has asked the States to procure antivenom serum under the National Health Mission.

Also, the polyvalent antivenom commonly used in India today is developed using the venom of the four snakes that together account for most fatal bites.

This means the antivenom often fails against the venom of unrelated snakes. To tackle these challenges, the World Health Assembly, the decision making body of the World Health Organisation (WHO), recently passed a resolution to support the worst-hit countries in developing effective antivenom and in standardising snakebite management protocols.

Influenced by wrong beliefs, illiterate and rural folk often resort to remedies that are useless and even hazardous, leading to disastrous consequences.

Tying a tight tourniquet, sometimes multiple tourniquets, on the bitten limb in the wrong belief that it will minimise the spread of venom, often compromises the blood supply in the limb leading to gangrene and subsequent amputation, Dr. Pillay, who heads the Forensic Medicine and Medical Toxicology department of the hospital, said.

Trying to identify the offending snake, according to Prof. Pillay, doesn’t serve any purpose. One must only go by the clinical picture to handle snakebite, he said.

Lethal bite: Common krait, spectacled cobra and saw-scaled viper (in picture) are among the most poisonous snakes in the country.   | Photo Credit: Special Arrangement

The right antivenom

Shifting the bite victims to allopathic hospitals without losing time, ensuring adequate stock of antivenom in government hospitals, which treat the majority of snakebite victims, and providing adequate training of physicians in the correct management of snakebite victims would make the difference between life and death, he said.

D. B. Padmakumar, Head, Department of Medicine, Government Medical College, Kollam, said non-availability of antivenom for sea snakes was affecting coastal districts such as Alappuzha.

Polyvalent anti-venom, used against the venom of kraits, cobras and vipers, is administered in such cases. The shortage of intensive care and ventilator facilities in some hospitals hampers management, he said.

Allowing the victims to rest and restricting their movements is important in the management of bite victims. Never suck blood from the wound as it may endanger the lives of first-aid providers.

Ideally, the victims should not be given any food or water as it may lead to vomiting. Creating incision is also not advised as it may lead to infection. Applying tight tourniquet near the wound could lead to gangrene.


Source: The Hindu