Antivenom is an effective treatment to prevent or reverse most of the harmful effects of snakebite envenoming, a potentially life-threatening disease caused by toxins in the bite of a venomous snake, as defined by the World Health Organization (WHO).
Antivenom is included in the WHO’s Model List of Essential Medicines and should be part of any primary healthcare package for snakebite treatment.
The WHO estimates that around 5 million snakebites occur each year globally, resulting in up to 2.7 million envenomings.
Published reports suggest that between 81,000 and 1,38,000 snakebite deaths occur each year across the world, while snakebite envenoming causes as many as 4,00,000 amputations and other permanent disabilities.
Experts point to a mix of factors behind high snakebite fatalities in India and suggest possible preventive solutions, such as changing century-old manufacturing protocols for antivenom, diversifying their coverage, fixing rural healthcare systems, bringing more awareness and a proper government policy on snakebite prevention.
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100-year-old protocol, low efficacy snake venom
According to Kartik Sunagar, a researcher at Evolutionary Venomics Lab at the Centre for Ecological Sciences (CES), Indian Institute of Science (IISc), India doesn’t suffer from antivenom shortage.
Several manufacturers such as Bharat Serums and Vaccines, Biological E and Haffkine Institute are producing it.
However, for over a hundred years, the protocol for manufacturing antivenom has not changed.
Manufacturers produce antivenom by isolating antibodies from horses that are injected with venom pooled from the ‘big four’ snakes — the common krait, the Indian cobra, the Russell’s viper and the saw-scaled viper.
Horse antibodies produced this way are believed to have low efficacy as antivenom.
“Because the manufacturing protocols are so outdated, the quality of antivenom is very poor. Sometimes one vial of these antibodies is not enough, but giving multiple vials can cause other complications in snakebite victims,” Sunagar told ThePrint.
Overuse of antivenoms can cause serum sickness in patients, which a lot of rural primary health centres (PHCs) do not know how to treat, he added.
However, even though science has made major advances in isolating antibodies against deadly pathogens in the lab, isolating human antibodies that can counter snake venom has remained a major challenge.
“Snake venoms are very complex, which is why it is very difficult to use recombinant technology to develop antibodies,” Sumagar said.
Recombinant technology, also known as genetic engineering or genetic recombination, refers to the process of combining genetic material from different sources to create a new combination of genes. This is usually done to create organisms that can produce desirable proteins — like antibodies against pathogens, or even edible proteins.
“We have shown in our previous research that even in the same species of snakes, the venom has variations,” Sunagar explained. This means that antivenom made from the venom of one snake may be less effective against the venom of other snakes.
Moreover, Sunagar said, snakebites are a poor man’s problem, which is why there is not much investment in their prevention and treatment. “Developing recombinant technology for antivenom requires a lot of research investment which unfortunately the government has not put in,” he pointed out.
Over the last couple of years, Wellcome Trust UK, a charitable foundation, has invested in this sector, Sunagar said, adding that “with its help, we have been able to set up the infrastructure to discover recombinant antibodies”.
Existing antivenom targets only the ‘big four’
The polyvalent antivenom currently developed in India targets the ‘big four’ snake species. However, India has at least 60 species of snakes that are labelled as venomous.
In many parts of India — especially the northeastern states — snakebites are not caused by the ‘big four’. Instead, other species of snakes are more prevalent whose venom cannot be countered by the existing commercially available antivenoms.
“In regions where these four species are not found, there are other species that cause death and disability, but we do not make antivenom targeting them,” Sunagar told ThePrint.
To tackle this issue, and to make the antivenoms more diverse, Sunagar’s team at IISc has partnered with Bharat Serum and Vaccines to develop antivenom for snakebites in Maharashtra and Rajasthan.
“The product is almost ready and we are going to test it soon. If it works, then this would be a great proof of concept and a major change to Indian antivenoms in over 100 years,” Sunagar said.
“We are trying see if can cover the whole of western India with just one antivenom,” he added.
However, even if regional antivenoms are developed, there has to be a facility where snake venom can be collected, and the IISc is planning the construction of one such multi-story facility that will house venomous snakes from across India for research and educational purposes.
“That will act as a constant supply chain for snake venom that can produce marketable antivenoms,” Sunagar said, adding that the construction of the building is about to begin.
Having a diverse collection of venomous snakes at one centre will allow scientists to accelerate the research on antivenoms developed for species other than the ‘big four’.
Need for community awareness
Priyanka Kadam, who runs the Snakebite Healing & Education Society, told ThePrint that the conversation around the need for regional antivenoms has been going on for long, but the problem is that antivenom is manufactured by private companies and is based on demand.
“They will produce according to what is in demand. The number of deaths reported from snakebites outside of the four big species is also very less, so there is little incentive to develop these (antivenom for other species),” she said.
Moreover, investment in the research sector will take five to 10 years to have any impact on the ground, she added.
“The low-hanging fruit, which lacks any investment, is community awareness,” Kadam said.
Even with the low efficacy antivenom, snakebites in India are treatable if the person gets the right healthcare on time, she explained.
“Unfortunately, in rural areas many people first go to faith healers and precious time is lost,” Kadam said.
What is needed, she added, is investment in community engagement — both to train PHC doctors and healthcare workers as well as raise awareness among people to seek medical care immediately after a snakebite.
Gaps in rural healthcare
According to Kadam, even if people go to community health centres for treatment, they do not get the right treatment there.
There is a massive need to improve the medical infrastructure, Kadam said. “By infrastructure, I am not just talking about antivenoms or ventilators on the ground — it also means having adequately trained medical staff.”
The reason that people go to faith-healers or ayurvedic practitioners in the first place is because doctors are often unavailable at PHCs, she added.
“PHCs are supposed to give 24×7 care but they are understaffed in most states. There will hardly be one or two doctors, and when they are on leave, nobody is available,” said Kadam.
If the patient has a neurotoxic snakebite (cobra or krait), which affects the nervous system and paralyses the entire system, even antivenoms will not help because the patient is unable to breathe.
Kadam pointed out that for such cases in rural areas, the nearest hospital may be 20 km to 150 km away. “The patient will not survive the ride.”
Similarly, disability among snakebite victims is high because many do not get the required long-term medical care.
Snakebite policy
Kadam told ThePrint that the government’s actions on snakebites had been encouraging in the last two years and it was working on a policy on snakebite prevention and control.
Earlier this year, the Union health ministry’s National Centre for Disease Control was reported to be working on a ‘National Action Plan for Snakebite Venom’.
Last year, the Centre started working on policy documents and asked all states to appoint a nodal officer for snakebites. This March, the environment ministry published a document recognising conflict with snakes as the biggest human-animal conflict in the world, said Kadam.
“Now that the government is in the process of publishing a national-level snakebite prevention and control strategy, it should work with experts and ensure initiatives that are impactful on the ground. Things should not get stuck in red-tapism,” she added.
(Edited by Nida Fatima Siddiqui)
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