A project exploring how environmental change may influence the incidence of snake bite has received a boost from a new global health research fund.

Every year between 420,000 and 1.8 million people are exposed to snake venom after being bitten by snakes. Claiming up to 120,000 lives worldwide, the majority of these incidents occur in rural areas of developing countries, affecting mostly agricultural workers and subsistence farmers. 

A new collaboration between the Grantham Institute – Climate Change and the Environment, the Liverpool School of Tropical Medicine, Tel Aviv University and the University of Kelaniya in Sri Lanka has been awarded over £500,000 to study the prevalence and drivers of snake bite, and explore how changes in climate and land use patterns may affect the likelihood of snake bite occurring.

 “Snake bite occurs in areas where humans and venomous snakes overlap and come into contact. Our focus is on predicting how that overlap might be influenced by environmental in addition to social factors, and how it could change in the future according to different climate and land-use change scenarios,” said Dr Kris Murray, Grantham Lecturer in Ecological Health.

The research team brings together clinical experts on snake bite, epidemiologists and ecologists, taking a multidisciplinary approach to tackling the problem.

Snakes and ladders 

The incidence of snake bite is strongly influenced by weather and seasons, with the monsoon for instance causing an annual spike in cases in India. The changes in temperature and weather conditions brought on by climate change may affect how and at what times humans are present in risky areas, but also the ranges of venomous snake species, their abundance or their behaviours. Some areas may become less risky (for instance if some snake species can no longer occur there), while others may become more risky (if for example they  become climatically more suitable to snakes). 

Meanwhile, as increasing amounts of land are converted to agricultural uses to feed a rapidly-growing global population, agricultural land and workers may encroach on new areas that venomous snake species call home. 

“We suspect that these changes could influence the risk of snake bite in many parts of the developing world, similar to the shifts in risk we are seeing or projecting for some infectious diseases such as dengue fever and Nipah virus,” said Murray.

Particularly in areas with limited healthcare provision, venomous snake bites are frequently fatal, while survivors often sustain long term health effects including kidney damage and limb injuries or amputation. Improved access to healthcare and a focus on prevention, for example through targeted public awareness campaigns, can reduce these harmful impacts but better insights and data are needed to target resources more effectively in affected areas. 

“We think that developing high resolution risk maps that incorporate the ecology of key biting species will be useful for making the most of very limited resources, and will help health professionals anticipate changes in risk,” said Murray. “We also think it could be good for snakes – helping to alleviate the conflict between snakes and people by better understanding their ecologies could support snake conservation and the benefits that snakes provide, such as crop pest control.”

Putting snake bite in the spotlight

Dr Murray also hopes that collecting more comprehensive data on snake bite will draw attention to this widespread, but neglected health threat. 

 “It’s pretty unbelievable when you start crunching the numbers – snake bite probably kills as many if not more people than much better known diseases like cholera, rabies, leishmaniasis and dengue. It’s perplexing to me that snake bite has received so little attention, in terms of research effort and health spending, in comparison to other diseases. We want to help do something about that,” he added.

“Venomous snakes are incredibly difficult creatures to study, which goes some way in explaining why we know so little about them and snake bite more broadly. But snake bite has a lot more in common with zoonotic diseases (where pathogenic agents, such as viruses, are transmitted between a vertebrate host and a human) than they do to most types of ‘accidents’, which is how they are often viewed. Recognising snake bite as a dynamic process where social and ecological factors combine to result in disease in people is an important starting point.”

The funding was awarded as part of the £1.5 billion Global Challenges Research Fund (GCRF), a new initiative which aims to harness the UK’s world-class research expertise to address issues affecting people in low and middle income countries. The 41 Foundation Awards led by the Medical Research Council (MRC), and supported by Arts and Humanities Research Council (AHRC), Biotechnology and Biological Sciences Research Council (BBSRC), Economic and Social Research Council (ESRC) and Natural Environment Research Council (NERC), have been allocated to support ambitious, novel and distinctive research in non-communicable diseases and infections.

Declan Mulkeen, the MRC’s Chief of Strategy said: “The five research councils involved have been working collectively to provide new and broader approaches to meet global research challenges. It’s encouraging to see these projects tackling the broader environmental and economic factors affecting health, as well as using new technologies to bring cost-effective treatments within reach.”

This research project is one of several projects at Imperial exploring the interactions between environmental change and human health, supported by the Grantham Institute.