Study Finds Climate Change Could Drive New Snakebite Hotspots In India

Climate change could be creating conditions conducive for venomous snakes to shift and spread into India's north and northeast, potentially increasing risks of snakebites in regions so far considered unsuitable for the species, a study has found.

The 'Big Four' refers to the four species of venomous snakes -- common krait, Russell's viper, echis carinatus and Indian cobra -- that are known to be responsible for the majority of snakebite cases among humans on the Indian subcontinent.

Researchers from Dibru-Saikhowa Conservation Society and Assam Agricultural University, and Pukyong National University in South Korea, projected that Haryana, Rajasthan and Assam might see an expansion in habitat suitable for the Big Four snakes, due to conditions driven by climate change -- rising heat and humidity.

Increasing human-snake interactions across rural and urban areas could present new challenges for public health and medical management, the team said.

Further, under continued warming, northeast states, such as Manipur, Meghalaya, Nagaland, and Arunachal Pradesh -- considered to currently lack a habitat conducive for snakes -- also may see notable increases of over 100 per cent, the findings published in the journal PLOS Neglected Tropical Diseases reveal.

Tropical and subtropical regions of the world experience a disproportionate impact of deaths due to a snakebite -- a neglected tropical disease. Cases in India are among the highest in the world.

Snakebite is among other neglected tropical diseases, such as dengue and malaria, which are expanding in geographic reach due to climate change, breaching regions traditionally seen to register low cases of the diseases.

The researchers used models depicting the current and future geographic reach of the Big Four snakes under varied climate scenarios in the future. Regional socioeconomic and public health data were also used to develop a snakebite risk index for Indian districts and states over the next 50 years.

"The risk index identified several southern Indian states and districts, such as Karnataka (including Chikkaballapura, Haveri, and Chitradurga) and Gujarat (Devbhumi Dwarka and Jamnagar), as having high vulnerability to snakebite," the authors wrote.

"Additionally, under climate change scenarios, many northern and northeastern states and districts, including Assam (Nagaon, Morigaon, and Golaghat), Manipur (Tengnoupal), and Rajasthan (Pratapgarh), have experienced an increased risk of snakebite, presenting a significant public health concern in these regions," they said.

The study is the first to combine climate patterns and geographic spread of species with socioeconomic vulnerability and healthcare capacity, with results showing that "climate change is not just an environmental crisis but it is also a looming public health crisis," the team said.

Local governments and international communities must intensify efforts to counter climate change and protect vulnerable regions from Big Four envenomation, the authors said.