By Apoorva Mandavilli
The snake struck 11-year-old Beatrice Ndanu Munyoki as she sat on a small stone, which lay atop a larger one, watching the family’s eight goats. She was idly running her fingers through the dirt when she saw a red head dart from between the stones and felt a sharp sting on her right index finger.
Never a crier, she ran to her father, David Mutunga, who was building a fence. He cut the cloth belt on her dress into strips with a machete, tied her arm in three places and rushed her to a hospital 30 minutes away on a motorcycle taxi.
As the day stretched on, her finger grew darker, but the hospital in Mwingi, a small town in Kenya, had no antidote for that kind of venom. Finally that evening in November 2023, she was taken by ambulance to another hospital and injected with antivenom.
When the finger blistered, swelled and turned black despite a second dose the next day, “I understood that they will now remove that part,” Mutunga said with tears in his eyes. Beatrice’s finger was amputated.
In Kenya, India, Brazil and dozens of other countries, snakes vie for the same land, water and sometimes food as people, with devastating consequences. Deforestation, human sprawl and climate change are exacerbating the problem.
According to official estimates, about 5 million people are bitten by snakes each year. About 120,000 die, and some 400,000 lose limbs to amputation.
The real toll is almost certainly much higher. Estimates are generally based on hospital records, but most snakebites occur in rural areas, far from dispensaries that stock antivenom and among people too poor to afford treatment.
“We don’t actually know the burden of snakebite for most countries of the world,” said Nicholas Casewell, a snake researcher at the Liverpool School of Tropical Medicine.
Scientists are now trying to better quantify the problem. In nearly every country studied so far, the true toll of snakebites has been found to be much higher than the numbers registered in hospital records.
The problem was mostly ignored until recently.
Venomous snakebite has jumped on and off the World Health Organization’s list of neglected tropical diseases. In 2019, the WHO announced a plan to halve the number of snakebite deaths by 2030 and the Wellcome Trust, a charity in Britain, invested 80 million pounds (about $102 million) into treatment research, a big boost.
Still, most countries have not allocated needed resources to fighting this danger, which mainly affects rural people with little political clout. Farmers, migrant workers, nomadic groups and residents of remote villages encounter snakes in their dilapidated homes, while sleeping on the floor, using outdoor toilets or walking barefoot.
India accounts for about half of snakebite cases globally, but some African countries lead the list relative to population size. “The fatality rate for snakebite episodes is much higher in sub-Saharan Africa,” said Diogo Martins, who leads research on the issue at Wellcome Trust.
Snakes avoid people as diligently as people avoid them. They are shy, biting only when they perceive danger.
“They know you are useless prey,” said Dr. George Omondi, who heads the Kenya Snakebite Research and Intervention Center in Nairobi, the capital. “They would rather spend their venom on something they could eat.”
Fear and hatred of snakes often drives people to kill them on sight, but the creatures have a role to play in the ecosystem, Omondi said.
There are about 4,000 known species of snakes, and some 200 are venomous enough to kill people. “There are many more new ones to be discovered,” said Kartik Sunagar, a researcher at the Indian Institute of Science.
Sub-Saharan Africa is home to dozens of snake species, but the most deadly and feared are the puff adder, cobra and black mamba.
Cobras and mambas have short, erect fangs at the front of the mouth that inject neurotoxins under the skin, paralyzing the victims. A black mamba’s venom is so toxic that it can kill people or prey within an hour.
Cobra bites also demand immediate attention, but with treatment recovery can be dramatic, reversing symptoms like a tape running backward. Spitting cobras can shoot venom into their prey’s eyes from up to 5 meters away, or about 16 feet.
Snakes like these are giants. Black mambas can stretch to 14 feet, and the longest king cobra ever recorded was 19 feet.
Puff adders are petite by contrast, as short as 6 inches and no longer than 6 feet, but very thick. They have long, retractable fangs that can deliver poison into muscle.
Their venom destroys blood-clotting factors, and victims die slow, gruesome deaths, bleeding in the brain, eyes and mouth.
Identifying the attacker can help tailor treatment. But many people never see the snake that bites them or, if they do, cannot identify it. To the untrained eye, venomous snakes may look indistinguishable from harmless ones.
The names don’t make it any easier. Green mambas are green, but black mambas are pale gray to dark brown; they are so-named because the inside of the mouth is black. They are better recognized by their coffin-shaped head and unnerving smile.
Some scientists are building artificial intelligence models to identify snakes, so that anyone with a smartphone might be able to distinguish them.
About a third of snakebites are in children. They occur less often among pregnant women, but the outcomes — which include spontaneous abortion, ruptured placentas, abruption, fetal malformations and death to both mother and fetus — can be catastrophic.
Nearly everyone in Africa could survive a snakebite if they had the right antidote and care. But stocking and delivering the right antivenom, at the right dosage and in time is tricky.
The first hour after the bite is crucial. If the swelling crosses the joint closest to the bite, “that shows that the venom is rapidly acting,” said Cecilia Ngari, a scientist at the Kenya snakebite research center.
Antivenom must be kept cold and sterile and administered intravenously. It may help even days after a bite, but it should ideally be administered within six hours.
There is only one antivenom manufacturer in all of sub-Saharan Africa, Johannesburg-based South African Vaccine Producers. Many other nations import antivenom from Asia and South America.
But antivenoms from one country often don’t work on snakebites in another. Antivenoms made in India, where kraits are most common, is useless against the black mambas or puff adders that terrorize Kenyans.
The fragmented market makes it hard for companies to earn healthy profits on antivenoms, so the supply has dwindled even as the need has risen.
To be effective, an antivenom should be tailored to the snake. Each species produces a special blend of dozens of toxins. Even within a species, the venom can vary by region, age, diet and season.
Antivenoms are no match for this complexity. They are still made much as they were 130 years ago: A small amount of venom is pumped into a horse or camel, and the antibodies produced in response are harvested and bottled.
Each vial can cost 8,000 Kenyan shillings (about $62), and treatment may require five, 10 or even 50 vials depending on the amount of venom coursing through the body, a ruinous expense for many rural families.
In Mwingi, everyone knows someone who has been bitten. Beatrice’s ordeal has left emotional scars on the entire family, her father said, and he is more fearful now as he goes about his work.
Beatrice herself was more positive, despite her missing right index finger. In the year after the surgery, she has taught herself to write with the other fingers on her right hand.
“I will not be scared,” she said.
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