An estimated 58,000 people die from snakebite in India every year. Just four species—the Indian cobra, common krait, Russell’s viper, and saw-scaled viper, collectively known as the ‘Big Four’—are responsible for the vast majority of bites. Of these, Russell’s viper causes half of the deaths.
Climate change adds an entirely new dimension to the problem of snakebite mortality and morbidity. By changing snakes’ geographical ranges, which involves contractions, expansions and shifts, it could create new hotspots where humans and snakes come in contact with each other more often and increase chances of more bites. This is according to a study published in the journal PLOS Neglected Tropical Diseases.
Imon Abedin, lead author and researcher at Dibru-Saikhowa Conservation Society, Tinsukia, Assam, tells Hot Rock their priority was to see human-snake interactions from the conservation point of view as well as from snakebite deaths point of view.
Their study integrates species distribution models, in a time of climate change, with socioeconomic vulnerability and availability of medical care. They used the presence records of the “big four” snakes along with environmental parameters to identify suitable habitats and projected these areas under different future climate scenarios.
To assess risk, Abedin says, they overlaid the suitable habitat areas with agricultural land and built-up regions, and combined this with the socioeconomic conditions and healthcare infrastructure of each region. This approach generated a dynamic risk index that reflects the potential for snakebite-related morbidity and mortality.
“Regions with lower socioeconomic deprivation and better healthcare availability were associated with lower risk index values, whereas higher deprivation, limited healthcare access, and greater overlap of snake habitats with agriculture and built-up areas increased the risk,” says Abedin.
The salient points include:
The big four are going to lose their suitable habitats in future.
Specifically, the suitable habitats for the big four snakes are projected to decline by more than 50 per cent under future climate scenarios as their climatic envelopes shift.
What this means is, Abedin tells Hot Rock, that these species may also shift their ranges, which could lead to snakebite cases emerging in previously unaffected areas.
As per the risk index, several southern Indian states and districts, such as Karnataka (Chikkaballapura, Haveri, and Chitradurga, etc.) and Gujarat (Devbhumi Dwarka and Jamnagar, etc.) are going to be more prone to snakebite.
Due to climate change, many northern and northeastern states and districts, including Assam (Nagaon, Morigaon, and Golaghat etc.), Manipur (Tengnoupal), and Rajasthan (Pratapgarh), are going to be facing snakebite problem.
At present, districts in the southern states such as Karnataka, Tamil Nadu, and Telangana are among the most vulnerable to snakebite-related mortality and morbidity. This vulnerability likely stems from the large overlap of snake habitats with agricultural or built-up areas, socioeconomic deprivation and limited healthcare facilities.
Abedin says, in the coming decades, the areas of highest vulnerability are projected to shift towards eastern India. The increased risk in northeastern India may be linked to socioeconomic deprivation and inadequate healthcare. Importantly, this risk can be managed by strengthening healthcare systems and improving the socioeconomic conditions of local communities. While snakebites may still occur, the associated mortality and morbidity can be greatly reduced if healthcare access, public awareness, and knowledge about prevention and treatment are enhanced.
“Ultimately, all these factors are interconnected.”
The study draws attention to the fact that this issue is not confined to rural areas. Urban regions may also experience snakebite risks. However, the extent and severity are much greater in rural areas, where interactions with snakes are more frequent and access to healthcare and other economic resources is often limited.
Abedin says the findings of the study will help government plan medical care, and help judicious use of medical resources in high-risk areas. The most effective response is to target high-risk districts, he says.
Once these areas are strengthened, efforts can then be extended to other regions. However, healthcare infrastructure alone is not sufficient.
Abedin says people in these regions must also be aware of the availability of treatment and understand the dos and don’ts during a snakebite incident. Moreover, a coordinated effort involving different sectors of society is crucial for an effective response during emergencies.
Encouragingly, he says, in recent times, numerous lives have been saved and individuals are now leading normal lives when treatment was provided promptly.
From a conservation standpoint, Northeast India harbours rich biodiversity and is recognised as a hotspot for flora and fauna. In many areas, conservation has been closely integrated with the lives and cultural practices of local communities. However, as development in the region is both necessary and ongoing, it is equally important to ensure that conservation remains a central focus.
Building resilience for the future will require a balanced approach that supports both biodiversity conservation and sustainable development in Northeast India. Although several conservation initiatives for different taxa are currently underway, these efforts must be supported and complemented with new initiatives targeting additional biodiversity.
“Conservation is not a short-term goal but a long-term commitment that requires sustained action. This is especially critical in Northeast India, which now represents one of the last refuges of biodiversity on the subcontinent.”
Back in 2015, Luis Fernando Chaves, then associated with Nagasaki University, published a study titled “Snakebites are associated with poverty, weather fluctuations, and El Niño”, in Science Advances. The study looked at snakebites reported in Costa Rica from 2005 to 2013 associated with meteorological fluctuations.
“Our analysis shows that snakebites are associated with changes in temperature and rainfall across time, and that unusually high numbers of snakebites occur during the cold and hot phases of ENSO,” they state.
“We found that periodicity in snakebites reflects snake reproductive phenology and is associated with ENSO. Snakebites are more likely to occur at high temperatures and may be significantly reduced after the rainy season. Snakebites cluster in Costa Rican areas with the heaviest rainfall, increase with poverty indicators, and decrease with altitude. Our results suggest that snakebites might vary as a result of climate change.”
