Sujatha, 41, was going about her duties on her employer’s corn field at Chowdikatte, a village in Karnataka’s Mysuru district. It was a winter afternoon in January 2020, and she’d finished her morning chores, taken a break for lunch and headed out to harvest the crop. Suddenly, she felt a stab of pain on her right ankle. She looked down and realised she’d been bitten by a snake. It was the highly venomous Russell’s viper. She shouted for help. A co-worker phoned her husband Ganesh, who was working in the next village.
Ganesh took her to a clinic about 15 kilometres away, run by local nuns, a place where, word had it, snakebite victims had been successfully treated. From about 2.30pm to midnight, Sujatha was treated with oils and concoctions. That didn’t work—she was vomiting, and her body began to swell up.
Over the next few days, Ganesh desperately sought treatment for Sujatha. At a government hospital in Mysuru city, he was told nothing could be done. After that, he tried a private hospital, where doctors said that Sujatha would need dialysis because of kidney failure. She remained in the hospital for six months. Post-discharge, she continued twice-weekly dialysis treatments in Mysuru, travelling 45 kilometres each way from her village to the city. After that, her treatment continued for another three months at a local hospital in Hunsur, closer to home.
Sujatha died in December, 11 months after being bitten in the corn field in Chowdikatte.
iran Bagade told me that Sujatha could have been saved if she was given antivenom. Bagade is a project coordinator with the Humane Society of India’s snakebite mitigation program in Karnataka, run in collaboration with herpetologist Gerry Martin’s non-profit group The Liana Trust. [1] Antivenom, Bagade said, is the only antidote that neutralises the toxic effects of a venomous snakebite. [2]
Sujatha was one of thousands of people who died of snakebite that year in India. The World Health Organisation estimates [3] that there are between 81,000 and 138,000 snakebite deaths worldwide every year. On average India sees, according to one estimate, 58,000 deaths annually—somewhere between 40 and 70 percent of the global total. That figure is from a paper about trends in national snakebite deaths between 2000-2019. [4] It was based on data collected during the Million Death Study, an initiative to understand causes of death in rural India, led by Prabhat Jha, a professor at the University of Toronto’s Dalla Lana School of Public Health.
The paper found that 94 percent of snakebite deaths occur in rural India. Half of the fatalities take place during the southwest monsoon season, from June to September. While the mortality figures are staggering, there’s also the uncounted thousands who lose digits and suffer serious health problems, such as kidney failure and muscle weakness, as a result of snakebites. Recent analysis suggested that, annually, snakebites cost Indians the equivalent of three million years of health and productivity. (Yes, you read that right.) [5]
A few years ago, the WHO put snakebite envenomation, the technical term for a potentially life-threatening disease caused by toxin from a snakebite, on its list of neglected tropical diseases, in the category of dengue, chikungunya and leprosy. In 2019, it launched an international initiative [6] to halve the number of deaths and disabilities snakebites cause over the next 12 years. “If that goal has to be met globally,” Jha said, “there has to be progress in India.”
ndia’s forests, deserts, hills, grasslands, plains and waters are home to a dazzling array of serpents—around 300 species in all. Of these, about 60 are venomous and medically important. [7] The Big Four of these 60 are responsible for a majority of deaths and morbidities across the country: the spectacled cobra (distinct eye pattern on the hood), the common krait (bluish-black with thin white bands), the saw-scaled viper, and the Russell’s viper (both covered in brown-and-black markings).
Humans and snakes co-exist in nearly every part of rural India. Conflict is inevitable. “You look at the way people talk about Australia having the most venomous snakes in the world, which is true,” the herpetologist Romulus Whitaker told me. “But it has the population of New Delhi in a vast country. We’ve got 1.3 billion or so people, more than half living in agricultural areas.” Whitaker added, as herpetologists often do, that it’s worth remembering that not all encounters involve venomous serpents. Also, snakes aren’t out to get us, and would rather avoid interactions with humans.
“Rich people don’t get bitten, folks in cities usually don’t get bitten. It’s sort of stayed under the radar.”
Agricultural areas attract rodents, among the primary prey of snakes. In these places, residents often walk barefoot or wearing flimsy slippers, including in the dark. When they accidentally step on a snake, the animal strikes in defence. The victims are typically low-income workers: farmers, labourers, cattle grazers.
That’s why Gerry Martin of the Liana Trust calls snakebite “a poor man’s disease,” which doesn’t get enough attention because of whom it affects. “Rich people don’t get bitten, folks in cities usually don’t get bitten,” he said. [8] “It’s sort of stayed under the radar.” Martin still sees people walk on overgrown paths instead of clear tracks. They wear slippers instead of gumboots in the fields, and walk without torches at night.
It’s tough to change this behaviour, particularly when there are real reasons for this reluctance. For one, the weather is often too hot for boots. Gnaneswar Ch, assistant coordinator for the snakebite mitigation project at the Madras Crocodile Bank Trust, told me that many rural residents complain about gumboots hardening the soil, which is bad when sowing seeds.
The enduring confidence in faith healing also makes it challenging to treat people quickly. In many parts of India, snakes are seen as mystical beings. They are worshipped and have magical properties attributed to them. (India’s pop culture, with movies and TV series that feature fantastic portrayals of snakes with magic powers, bears testament to how widespread and unshakeable these beliefs are.) Martin explained that the snake’s ability to cause death with a single bite probably influenced how people view it. “It had to be a supernatural animal and the only way to deal with that is with supernatural remedies,” he said.
City-dwellers may be able to trust and access modern medical facilities more readily, but in some villages, babas and spiritual healers are the first to be approached when there is an illness or injury. These individuals often have no medical knowledge—they resort to chants and dubious natural remedies when dealing with patients. Their claims of success in treating snakebites are bolstered by the fact that a large number of bites aren’t eventually fatal. “You could have a 90 percent success rate, even though the methods are totally bogus,” Whitaker pointed out. “You could be giving Coca-Cola instead of a herbal preparation.”
Priyanka Kadam, the president and founder of the Snakebite Healing and Education Society (SHE), met several faith healers during her travels around India. In Jharkhand, she came across two young boys who claimed to have celestial powers to treat snakebites. When diagnosing a victim and deciding on treatment, the boys would rotate a stick above the patient, in a sort of wide arc, to determine the type of snake that had caused the bite. If the stick pointed up it was venomous, if it pointed down, it was non-venomous.
Sometimes, the treatment is as mystifying as the method of diagnosis. Martin recounted disturbing details from a video he saw a few years ago. A young child was bitten by a cobra somewhere in North India. A faith healer suggested letting the animal bite the child again to “recall its venom.” In the clip, a person is holding the snake as it sinks its fangs again into the tiny body. The child died.
But alternative treatments can be tough to come by. Hospitals are far away and expensive. Some experts I spoke to pointed to the shortage of doctors in primary health centres (PHCs) [9] as a major concern in dealing with snakebites. “The sure-shot bullet to take care of this is to have doctors manning the PHCs,” said cardiologist Dr. Jaideep Menon, lead investigator on an Indian Council of Medical Research-sponsored study on the problem of snakebites in India.
Kadam told me about one of her trips to Nandurbar district in Maharashtra. “I visited four tehsils out of five on several occasions and I saw a doctor only once,” she said. Difficult conditions, including lack of infrastructure and basic amenities, make a rural posting unappealing for doctors. Those with families sometimes live separately, with their partners living in towns and cities. It isn’t an easy life. “The government should work towards bettering the working conditions of rural medical staff,” Kadam said.
It’s not enough that doctors be present; they also need to be trained in diagnosing and treating venomous snakebites. Antivenom can help fight toxins, but can also cause allergic reactions, including anaphylactic shock. [10] The three doctors I spoke to said snakebite treatment takes up only a few pages in the MBBS curriculum. [11] It is mostly part of the sections dealing with forensic medicine, which Menon pointed out is the “medical text of the dead.” Instead, he argued, it should be made part of the emergency or internal medicine syllabus.
enom is a complex cocktail of peptides, enzymatic and non-enzymatic proteins, salts and other substances. It is deployed by creatures ranging from snakes and scorpions to spiders and jellyfish to kill prey and protect themselves from predators. It’s a chemical weapon, evolved over millennia.
Kartik Sunagar, an assistant professor at the Indian Institute of Science, Bengaluru, has spent years studying venoms. At his Evolutionary Venomics Lab established in 2017, the team is working to know more about the evolution of toxins and the molecular mechanisms of venom compositions. “I knew that the same proteins found in us are found in venoms,” Sunagar said. “I was intrigued by how something that’s so harmless and useful for us gets transformed into some of the most potent toxins.”
Venom has evolved to work specifically against the biological mechanisms of a snake’s natural prey—which may be reptiles, amphibians or small mammals. Despite the exceedingly rare accounts of snakes that have swallowed humans whole, we aren’t their natural prey. But toxins that target mammalian systems, such as those of rats, affect us by extension.
Those effects can vary. A member of the viper family, such as the Russell’s viper, injects hemotoxins that affect the victim’s circulatory system. Nicholas Casewell, head of the Centre for Snakebite Research & Interventions at the Liverpool School of Tropical Medicine, explained that these toxins punch holes in blood vessels, leading to bleeding at the bite site, internally and in the mouth. Some toxins can also impact clotting processes. “So you have this perfect storm, of some toxins causing blood vessel damage and others stopping you from repairing that via clotting. It’s how people bleed to death,” he said.
Cobra and krait bites inject neurotoxins into their prey, debilitating the nervous system and causing paralysis. The venom goes to work in the spaces between neurons and muscle fibres, which are a kind of synaptic cleft. It impairs movement by preventing signals passing from the brain to, say, the hand or the leg. Casewell described the process as a descending paralysis that begins with the victim losing the ability to open their eyes, and then moves down to the rest of the body. Death occurs when the muscles that control breathing are affected.
Then, there are venoms like cytotoxins, which don’t necessarily cause death, but lead to disfigurements that can have long-lasting consequences. They damage cells and tissues at the bite site, and can lead to swelling, blood-filled blisters (“a big, ripe-looking, jamun-type of blister” was how Martin described the effect of a bite he sustained) and even tissue death leading to amputation. In rural areas, the loss of a limb or even fingers can be a fell swoop to livelihoods.
Crucially, a venom’s effect also depends on how quickly it is absorbed into the bloodstream. Dr. Menon said that a bite on a lower limb takes longer to enter the circulatory system than one on the face. In some cases, when people who are relieving themselves in fields are bitten on the buttocks, the rate of venom absorption is slowed down by the presence of subcutaneous fat. Venom spreads faster when the heart rate rises due to panic.
For all the varieties of venom, and the complex ways in which they can cause damage, there’s only one solution: antivenom.
“If the venom toxin is a key, the antibody is a very specific lock.”
It’s a manufactured substance, made in ways similar to a vaccine, which contains precisely targeted antibodies that bind themselves to toxins. “If the venom toxin is a key, the antibody is a very specific lock,” Casewell explained. “It just sticks to that key and prevents the toxin from doing its job.”
To manufacture antivenom, venom is injected into an equine or bovine animal in a series of small doses over about four or five months, until the animal starts developing antibodies. Then, blood is drawn, and the plasma is separated and purified. Antivenom is available in liquid or powder form in tiny vials. [12] In India, it’s sold largely to state governments, many of whom requisition it through a tender system and then distribute it to local hospitals and PHCs. [13] Manufacturers across the world follow the same production methods developed in the late 1800s.
An antivenom is effective against a particular snake’s bite if the toxins present in its venom are used during production. Since snake populations and venom potencies differ across countries, each manufacturer has to use local venoms.
In India, antivenom is made with venom extracted from the Big Four. [14] All vials of Indian antivenom carry the same information: each millilitre of antivenom neutralises 0.6 milligram of cobra and Russell’s viper venom, and 0.45 milligram of common krait and saw-scaled viper venom.
he walls of the venom extraction pit at the Irula Snake Catchers’ Industrial Cooperative Society (ISCICS) are painted in stripes of green, yellow and red. The pit’s floor is filled with clay pots, the mouths of which are covered by a white cloth held in place by an elastic band. In a video I watched, Muthu, a man from the Irula tribe, was in the pit. His protective gear was minimal—rubber boots and a hooked stick. Hisses emanated from the surrounding matkas.
He calmly removed the cloth from a pot and used the stick to extract a cobra whose hood flared the second it was brought out. Holding the tail in one hand and using the hook to handle the front half, Muthu walked to a large raised platform in the middle of the pit where his colleague Varadan stood.
Together, the men measured the cobra and clipped a scale from its underside with a pair of scissors. Varadan then held the snake firmly behind its head and turned to a table mounted with a glass container, covered by a rubber membrane.
The cobra, agitated as it was, struck the covering as soon as it sensed something nearby. Droplets of venom began to drip from its fangs into the receptacle.
This scene plays out nearly daily at ISCICS, located in a section of the Madras Crocodile Bank Trust, about an hour south of Chennai. ISCICS is the source of a vast majority of venom supplied in India. The society was started by Romulus Whitaker in 1978 to provide economic support for the Irula tribe, historically skilled at dealing with wildlife, especially snakes. [15]
Before the Wildlife Protection Act came into force in 1972, some Irula people leveraged their skills to supply snakeskins for the animal trade. Over the years, they have been squeezed out of their forest homes in southern states, including Kerala and Tamil Nadu, due to urbanisation and changing land use patterns. Many took up jobs as ditch diggers and labourers.
Whitaker, who had already been working with the tribe to catch snakes for Mumbai’s Haffkine Institute, [16] didn’t want to see their expertise wasted. “They had these incredible skills of finding holes in the ground,” he told me. “They can tell from the tracks whether there is an animal living in the hole and whether it is worth digging it out.”
Today, the society has about 350 active members who are granted annual licenses by the Tamil Nadu Forest Department to catch predetermined numbers of the Big Four snakes from within the state. The members deposit the animals at the society and are paid a fixed rate, explained Balaji Santhanagopal, secretary-in-charge of the ISCICS. “₹2300 for a cobra, ₹2300 for a Russell’s viper, ₹850 for a krait and ₹300 for a saw-scaled viper.” The rates are revised every few years.
At the centre, snakes are kept in the clay pots for four weeks and venom is extracted once a week. After each session, the handler clips scales from the snake’s underside to track the number of sessions completed. The animal is released after a month.
The collected venom is freeze-dried and sold in powder form to antivenom manufacturers, such as Pune-based private firm Premium Serums. Dr. Milind Khadilkar, technical director of Premium Serums, said approximate prices for a gram of venom can begin at around ₹23,000.
The Tamil Nadu Commissionerate of Industries and Commerce helps administer the ISCICS and the state Forest Department oversees sales. “We (ISCICS) have already done ₹30 lakh of turnover till November, every year we do about ₹50 lakh to ₹1 crore plus,” Anu George, Industries Commissioner and Director of Industries & Commerce, Tamil Nadu, told me in December last year.
While the ISCICS is one of the largest venom suppliers in the country, Mumbai’s Haffkine Institute for Training, Research and Testing is the oldest. Established in 1899 and named after Dr. Waldemar Haffkine, the creator of vaccines for cholera and the plague, the institute has been working on venom research since at least 1920. [17]
Like the ISCICS, Haffkine Institute has its own venom extraction protocols. Dr. Mrunal Ghag Sawant, head of the departments of zoonosis and toxicology, explained that the institute’s team of scientists and researchers receives permits from the Maharashtra Forest Department to collect snakes from across the state. The snakes are quarantined for a week for acclimatisation and staff monitor their health before milking. Extraction is done once a fortnight, and the snakes are released after 90 days. The venoms supplied by places like ISCICS and Haffkine are used by companies to create antivenom with a standard potency. It’s used all over India.
But there’s a problem with this approach to antivenom production. For one, though the venoms of only the Big Four are used to make antivenoms, other species present equally serious threats in many parts of the country.
In 2019, Sunagar and his colleagues at the Evolutionary Venomics Lab published a paper about the efficacy of Indian antivenom in the treatment of bites from non-Big Four snakes. [18] The snakes in the study were the Sochurek’s saw-scaled viper, the Sind krait, the banded krait and two different populations of the monocled cobra. Samples were collected from five states: Maharashtra, Arunachal Pradesh, Rajasthan, Punjab, and West Bengal.
The researchers tested antivenoms from four companies [19] using a combination of in vitro and in vivo tests. While all products bound to the venoms of the Big Four, they exhibited “varying degrees of cross-reactivity” or differential degrees of binding against the venoms of the other species. For instance, all the commercial antivenoms recognised spectacled cobra venom from Maharashtra but differed in their bindings against the monocled cobra venom. In the case of the Sochurek’s saw-scaled viper, only the antivenom of Premium Serums exhibited “relatively better binding.”
“Scientific data highlighting the burden of envenoming by the ‘neglected many’ in India is currently lacking,” Sunagar told me. “The non-Big Four species possess venoms that are nearly as toxic, if not more, than their Big Four counterparts, and are very abundant in the regions where they thrive. There’s no reason why they wouldn’t significantly contribute to snakebite mortality and morbidity figures in the country.”
This wasn’t all. The team also found that all four antivenoms had “poor binding capabilities” against certain populations of the common krait, even though its venom is used in manufacturing the antivenom. This insight then became the subject of another study. Published earlier this year, it looked at how venom variations across different populations of the same species affected antivenom performance. [20]
Researchers studied different populations of the spectacled cobra taken from six distinct biogeographical zones across India: semi-arid (Punjab), Gangetic plains (West Bengal), desert (Rajasthan), Western Ghats (Maharashtra), coastal populations (Tamil Nadu and Andhra Pradesh) and Deccan Plateau (Madhya Pradesh).
The research found that there were “considerable differences in the composition, pharmacological effects and potencies of geographically distinct venoms from this species,” which had “alarming repercussions on antivenom therapy.” The commercially available antivenoms were simply not effective enough across the country. For instance, they exhibited “a complete lack of neutralisation” against a desert population of the cobra when tested on mice.
The conclusion? “A pressing need to innovate pan-India effective antivenoms to safeguard the lives, limbs and livelihoods of the country’s 200,000 annual snakebite victims.”
omasekar Seshagiri, a biologist and geneticist, believes there is a better way to make antivenom. Seshagiri and a global team of researchers have spent the last few years trying to understand the genetic code underlying cobra venom glands.
“You can buy a bottle of aspirin and it’ll tell you exactly what’s in the bottle and the chemical formula. You buy antivenom and it’ll say antibodies derived from a horse,” Seshagiri said. “It’s medicine practice as if we’re living 200 years ago but we have the ability to change that. That’s our goal with sequencing these genomes.”
The cobra’s venom-producing gland expresses about 12,000 protein-coding genes, [21] the team found. Only 139 of these had the signature of a toxin. And of those 139, only about 19 were exclusively expressed in the venom gland. The rest were found in other tissues, suggesting they might not be relevant from the venom function point of view. [22]
Seshagiri believes this information can transform the antivenom manufacturing process. It can potentially do away with the need to inject horses with extracted venom. It involves a process called recombinant DNA technology—essentially splicing DNA from one organism into another to produce certain proteins in large quantities. In this case, the genetic code for snake venom is inserted into a bacteria, tricking it to create toxins in a test tube.
“You can buy a bottle of aspirin and it’ll tell you exactly what’s in the bottle and the chemical formula. You buy antivenom and it’ll say antibodies derived from a horse.”
He explained the idea with the example of insulin production. In the past, insulin used to treat diabetes was derived from the pancreas of pigs or cows, taken from slaughterhouses. In the 1970s, researchers figured out the DNA code for insulin in the human body. “You could take that code and stick it into bacteria, like E.coli, and the bacteria starts making insulin recombinantly,” he said. “Then, you crack open the bug and purify the insulin. You no longer need slaughterhouses and pigs. This democratised the availability of insulin.”
The idea is to create venom toxins recombinantly and then use synthetic antibody development technology to produce neutralising antibodies for different toxins. I asked Seshagiri what could be done to tackle the sheer number of venom variations. “While that is an important issue to consider, we cannot afford to be paralysed by it while so many are dying,” he said. “If we start modernising antivenom development and production, we can easily tackle the variation issue. It’s like the Covid virus variants. They are going to be there and we can solve (the problem) if we tackle the virus first without worrying about the variants.”
The structural similarities between basic toxin proteins in serpent species makes it possible to create common neutralising antibodies, Seshagiri said. Such antibodies that counter venom from multiple species, he added, can be combined to eventually create a “broad spectrum antivenom.”
Some researchers are looking beyond antibodies. Nicholas Casewell’s team at the Liverpool School of Tropical Medicine is researching the use of medical drugs. “In snake venoms, there are five or six key toxin families. Within each family, a snake might have different toxins, but they’re all related to one another and share common features. That’s what we’re trying to exploit,” Casewell said.
In a paper published in December 2020, Casewell’s team described how, during pre-clinical trials on mice, a combination of two drugs that acted on enzymatic families [23] present in hemotoxic venoms were found to neutralise viper venoms sourced from Africa, South Asia and Central America. [24]
Drug therapy, Casewell explained, is promising for a few reasons. For one, the drugs can be taken orally, whereas antivenom must be injected intravenously. Drugs can also be consumed quickly, without the physical presence of a medical professional, and could be cheaper to manufacture.
However, these new treatments, whether the gene-based synthetic antivenom or the drug therapies, are years away from being made available to the public. A more immediate solution for antivenom deficiencies, according to some experts, is the development of regional therapies. “The venoms should be sourced from local populations of medically relevant snakes,” Sunagar told me. “Basically it’s the Big Four plus a couple of additional snake species in each region that we need to account for.”
Regional serpentariums will allow for the collection of more varied venoms. Martin, the herpetologist, is working on setting one up in Karnataka. He said it will be ready by the end of this year and will house 800 snakes. Dr. D.C. Patel, an expert in treating snakebites in Gujarat, said he has been granted permission by the state government to set up a research institute and collection centre in Dharampur, Valsad district.
Experts are also engaged in the more immediate groundwork of mitigating the effects of snakebite. Kadam, Martin, the team at the Madras Crocodile Bank Trust (MCBT) and others run campaigns and drives to educate communities about peaceful coexistence with snakes. They distribute gumboots, torches, solar lanterns and mosquito nets. [25] Of course, handing out supplies is of little use if people don’t use them. Whitaker recounted how a community in West Bengal used the mosquito nets for fishing instead.
And so, organisations like Snakebite Healing and Education Society (SHE), which Kadam heads, have created educational videos to spread awareness about preventing and treating snakebite. SHE has produced videos in 12 Indian languages including Hindi, Marathi, Gujarati, Telugu, Assamese and Odia. In each, a narrator gravely issues instructions for what to do in case of a snakebite: keep the victim calm and still; immobilise the bitten limb; never try to remove venom by cutting or sucking. Videos put out by the MCBT urge people to rush victims to the hospital and stay away from local healers.
Gnaneswar Ch of the MCBT explained that over the past three years, the organisation had directed at least 80 percent of its efforts towards educating communities. “We explain it by asking what happens if a person falls off a speeding bike and breaks his head,” he said. “That person goes to the hospital. A snakebite is an emergency, like a road accident.”
In Gujarat, Dr. Patel teaches people how to identify snakes and understand their behaviour. “Cobra bites mostly occur in and around the house,” Patel said. “They very rarely occur in the farm because the cobra comes near the house for prey. Common krait bites usually happen between 10pm to 4am during the monsoon. Russell’s viper bites occur while working in farms, same for the saw-scaled viper.”
Given how big the country is, Whitaker described the concerted efforts of the NGOs as a “drop in the bucket.” He is confident that things are heading in the right direction, but believes that governments need to get involved to speed up solutions. “I’m surprised because the world watches India’s achievements but also sees the ridiculous things going on that aren’t improving,” he said. “This is one of them. So let’s wake up and do it.”
Kamakshi Ayyar is a freelance journalist based in Mumbai. She tweets @kamakshi138.