In the late 1970s, a 50-year-old farmer was working in his fields in the Hausa region of west Africa when was he was bitten on the ankle by a snake, probably a carpet viper. Within two hours his leg was badly swollen. The unnamed man, whose case is included in a report by a group of doctors led by Oxford University tropical medicine specialist David Warrell took herbal medicine but continued to sicken. Six days later he was taken to hospital, where doctors found that his urine was bloodstained and he had suffered intense internal haemorrhages. A day later, he died.

The farmer’s fate was grim, if not uncommon at the time, but now, decades later, deaths from snakebites are still on the rise. Recent evidence shows that hundreds of thousands of individuals are dying every year as a result of encounters with cobras, vipers or kraits.

It is estimated that a resurgence of the scourge of snakebites in Africa and Asia could soon account for a quarter of million deaths every year. In the past, deaths from snakebites have been poorly reported and the extent of the crisis underestimated. However, doctors in India recently carried out a detailed survey and discovered that around 46,000 people in the country died from snakebites every year. Official statistics had suggested that the figure was only around 1,000. Similarly in Bangladesh, a detailed survey revealed that the annual snakebite death toll there was around 6,000.

Facebook Twitter Pinterest Treating snakebite with a herbal and mud paste, Madhya Pradesh, India. Photograph: Alamy

“These two sets of figures are significant, for they suggest the estimate made by a World Health Organisation-sponsored study that snakes kill around 100,000 people a year across the globe may be a serious underestimate,” said Warrell. “After all, we now know that more than 50,000 men, women and children are dying in India and Bangladesh from snakebites each year – and that figure is coming from just two nations. We also know that countries such as the Democratic Republic of Congo have enormous numbers of venomous snakes but provide no reliable data of any kind about snakebite deaths within their borders. So I would say it is more likely that 200,000 or possibly more deaths a year are caused by snakes across the globe.”

In developing countries struggling to cope with HIV, malaria, tuberculosis and other diseases, the problem posed by growing numbers of bites by venomous snakes – examples include the carpet viper and the spectacled cobra – is particularly unwelcome.

Facebook Twitter Pinterest A young man in South Sudan had his left leg amputated after a severe infection caused by snakebite. Photograph: Pierre-Yves Bernard/AP

“The trouble is that many nations have no real knowledge of how bad the problem is within their borders,” added Warrell. This point is backed by the United Nations, which has described snakebites as “a neglected threat to public health”.

It is not just the death rate from snakebites that is raising concerns. As Warrell also pointed out, many people survive bites from snakes, but often at a terrible price. “Victims, who are often agricultural workers, lose legs or arms or fingers and can no longer hold down their jobs. Children’s limbs become gangrenous after being bitten by snakes and have to be amputated. They are blighted for life as a result. Girls have their marriage prospects ruined. The price of surviving a snakebite is often terrible.”

Lorenzo Savioli, a former director of the World Health Organisation’s department for the control of neglected tropical diseases, said: “Snakebites cause severe disability, bring misery to families and kill thousands of people. We need to act effectively to control the problem.”

Dealing with snakebites is likely to grow harder in the next few years, because existing stocks of the important antivenom Fav-Afrique, made by UK-based Sanofi Pasteur , will expire next June. The company stopped producing the antivenom last year. “We are now facing a real crisis,” said Gabriel Alcoba, snakebite adviser to Doctors Without Borders.

Pharmaceuticals companies in South Africa, India, Mexico and Costa Rica are working on replacement antivenoms, but these have yet to be tested or marketed and may take years to be ready for widespread use. “None of the possible successors to Fav-Afrique have yet been adequately tested,” added Warrell.

Scientists say a handful of species are the main culprits for soaring snakebite deaths in the developing world. These include carpet vipers, spitting cobras and puff adders in Africa and spectacled cobras, common kraits, Russell’s vipers and saw-scaled vipers in India and south-east Asia. In most cases the creatures kill by injecting a toxin that either causes serious internal bleeding or paralysis. When they bite their natural prey – rats or mice, for example – this kills them almost instantly. Humans, being bigger, can take much longer to succumb. But as veins and arteries leak, and serious internal bleeding takes place, death can come within days.



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However, these are not necessarily the world’s most venomous snakes. The venom of the black mamba is more toxic than that of the carpet viper, for example. But the former rarely comes into contract within humans. By contrast, the carpet viper is often found in fields and undergrowth.

“Farm workers stand on them or startle them and get bitten,” said Warrell. “Obviously, antivenom is a crucial part of any treatment. But just acknowledging the problem and its extent would be a major breakthrough. Simple preventive measures could then be introduced. Providing farm workers with boots would be an enormous help, for example. They usually work in bare feet, and that is where most get bitten.”