WHO formally listed snakebite envenoming as a highest priority neglected tropical disease in June 2017. What makes snakebite a ‘neglected tropical disease’?
According to the WHO there are four criteria that define an illness as a neglected tropical disease, and snakebite envenoming satisfies each of them: First, there is a significant burden of mortality and morbidity. Snakebite envenoming is a high-impact disease. Secondly, a majority of incidents of snakebite occur in the world’s tropical and sub-tropical regions, and it particularly impacts the poor – snakebite is a tropical disease. Thirdly, snakebite is amenable to treatment, as well as prevention – the impact of snakebite can be mitigated now if we make the effort to do so. Finally, the overall level of investment in research addressing snakebite, from prevention to diagnosis to treatment and rehabilitation, is exceptionally low in comparison to its impact – snakebite is a neglected disease.
Though the exact number of snake bites is unknown, an estimated 5.4 million people are bitten each year with up to 2.7 million envenomings. Around 81 000 to 138 000 people die each year as a result of snake bites, and around three times as many other permanent disabilities are caused by snakebites annually.
Bites by venomous snakes can cause paralysis that may prevent breathing, bleeding disorders that can lead to a fatal haemorrhage, irreversible kidney failure and tissue damage that can cause permanent disability and limb amputation.
Agricultural workers and children are the most affected. Children often suffer more severe effects than adults, due to their smaller body mass.
Given that a majority of bite sufferers are among the most productive members of society (young, working age men and women), disablement following snakebite can prevent survivors from earning an income, making them a lifelong financial burden for their family members. In addition, snakebite survivors may suffer disfigurement, post-traumatic stress disorder, stigma and social exclusion.