The Snakebite Problem

A Kwazulu-Natal boy, bitten by a puff adder, facing a life of disability.

A ‘DISEASE’ OF POVERTY

Snakebite affects the lives of around 4.5 million people worldwide every year; seriously injuring 2.7 million men, women and children, and claiming some 125,000 lives. Globally the greatest burden is experienced in the tropical world; where many nations remain under developed or suffer from poor governance, political and/or social, conflict, resource scarcity, high disease burdens, or food insecurity. The available evidence shows that it is in the world’s poorest economies that the burden of snakebite mortality is the greatest, and survival is no guarantee of a full recovery, with many thousands of victims being left permanently disabled and emotionally destroyed by their injuries.

 

The World Health Organisation added snakebite to the list of Neglected Tropical Diseases in 2009, but made no provision to seek global funding to do anything about the problem. Like all endeavours, global health is highly politicized, and it wasn’t long before snakebite was downgraded by WHO under a sub-definition: “Other ‘neglected’ conditions“. This belies the extent of the problem – snakebite is a global catastrophe affecting millions of the world’s poorest, and least empowered people. A 1998 WHO analysis of global snakebite envenoming incidence and mortality provided figures that can be used to place snakebite in comparison to other tropical illnesses:

 Disease Incidence Deaths
Snakebite envenoming 2,682,000 100,000
Chaga’s disease 217,000 14,000
Cholera 178,000 4,000
Dengue Haemorrhagic fever 73,000 19,000
Leishmaniasis 1,691,000 51,000
Japanese encephalitis 44,000 14,000
Schistosomiasis 5,733,000 15,000
Yellow fever 2,100 100

Part of the explanation for why snakebite towers over many of these other diseases in terms of numbers, perhaps lies in the fact that of all of the other neglected tropical diseases shown have been subject to substantial control programs by the international community, while snakebite remains largely unfunded and ignored among global public health priorities. The Global Snakebite Initiative was born out of the desire by a group of international snakebite researchers to shift attention from simply reporting the problems, to actively do something to solve them.

Nigerian girl with lasting scars and debilitating contractures following a bite from a black-necked spitting cobra.

THE INDIVIDUAL TRAGEDY OF SNAKEBITE

The reality too, is that the tragedy of snakebite is not all about large numbers of victims. A snakebite is a terrifying experience at an individual level, perhaps more so for young children, who are often over-represented in snakebite numbers, and may not be old enough to comprehend what has occurred or understand the cause of their distress or suffering. While a painful death is how Hollywood typically protrays snakebites in film, the reality is far more distressing that most people could imagine, and the consequences are often social stigmatisation and ostracism. Snakebite can have devastating physiological effects on the human body, because snake venom toxins have evolved to target almost every type of bodily function or body part, including:

  • Nerve toxins that cause potentially lethal paralysis, that may lead to death from slow suffocation;
  • Enyzmes that mimic natural blood clotting proteins in our own blood, which can disrupt the normal clotting activity leading either to catastrophic haemorrhage, or in some cases, deadly blood clots that can affect the heart, lungs, brain or other organs;
  • Proteins that destroy skin, muscle and other tissue causing horrific destruction to hands, arms, feet and legs, often leaving no alternative other than amputation;
  • Toxins that affect the normal functions of the heart, liver, kidneys and other body organs, or which destroy vital structures like the pituitary glands. Organ failures can lead to slow deaths from problems such as acute kidney injury, which stops the body from effectively producing urine to remove wastes, causing a slow painful death in the absence of treatment;
  • Venom components that cause blood vessel walls to leak, and fluid to accumulate in tissue, causing painful swelling and oedema, as well as peptides that trigger nerve receptors causing agonising local and generalised pain.