Poisonous snakebites kill many more people in South Asia than is ever reported, and so the problem isn’t being treated like a critical public-health issue, a group of snakebite experts say.
India, which has one of the biggest snakebite problems in the world, registered 2,000 deaths from venom in 2005. But a “verbal autopsy” project that sought to establish cause of death of one million people found that 46,000 of them died of snakebites – with that level of underreporting typical across the region, according to David Warrell, co-author of research presented in the journal PLoS Neglected Tropical Diseases. The real numbers show one Indian dies of a snakebite for every two who die of AIDS.
And it’s a growing problem in the region. Climate change is causing an increase in natural disasters such as cyclones and floods, which force people and snakes to seek shelter on the same remaining dry land. In the Bangladesh floods of 2007, snakebites were a greater cause of death than water-borne diseases.
“In the 21st century, snakebite is the most neglected of all the neglected tropical diseases,” said Prof. Warrell, who is emeritus professor of tropical medicine at the University of Oxford. He joined other experts in a special session on the neglect of snakebite at the American Society of Tropical Medicine and Hygiene’s annual meeting.
“The deaths and suffering from venomous snakebites remain largely invisible to the global health community.”
Diagnostics, anti-venoms, and rural treatment protocols are not getting the attention they deserve because this is perceived as an old-fashioned problem, and the rural poor are paying the price, added Ulrich Kuch, who heads the Emerging and Neglected Tropical Diseases Unit at the Biodiversity and Climate Research Centre in Frankfurt, Germany.
The main reason snakebite deaths are not counted is that victims rarely end up in the health system: in many cases, they do not bother travelling to health centres, because they know that no treatment is available there. While India is a huge producer of some anti-venoms, these are not distributed widely in rural areas, Dr. Kuch said, and scarce rural health staff lack the skills to treat snakebite.
“Even if you get to a health facility early enough, if there is no anti-venom or nobody there who knows how to give it to you and administer other care – then you’re in deep trouble.”
Instead many people bitten turn to snake charmers – 86 per cent, in a study of Bangladeshi victims, compared with 3 per cent who went to hospital. Snake charmers are traditionally believed to have some skill in treating bites. In fact, Dr. Kuch noted, they can provide no treatment at all – but because not every snakebite is accompanied by envenomation (the injection of venom into the victim) some victims don’t fall ill – allowing the snake charmers to claim a reasonable rate of “cures” and remain in the business of treatment. In every case where medical treatment and anti-venom is available, he added, people will choose that.
There have been few new developments in treating snakebite since anti-venoms came into use more than a century ago, but researchers this week presented several innovations.
The first is a simple test – done with a single drop of blood – that will prove envenomation and show what kind of snake caused the bite. Even when people do have access to medical care, Dr. Kuch noted, that is often not enough to prevent serious disability.
Because anti-venoms are scarce, treatment providers will wait until the bite victim shows confirmed signs of envenomation rather than waste the precious serum – but for some species of snake, by the time those signs are visible, the victim has suffered irreversible nerve or tissue damage. In addition, many victims are treated with the wrong anti-venom, which is useless: India, for example, distributes the anti-venoms for only four snakes in its public-health sector, based on a widely held but erroneous belief that they cause the bulk of bites.
Dr. Kuch said the plan is for the new tests, now going into clinical trials, to be cheap and easy enough for use at the most basic rural health centre. They will produce results in just 20 minutes. The first tests are for the bite of the Russell’s viper, a leading cause of bites across South Asia, and the krait. (Kraits frequently live in, or come into, rural houses at night, hunting mice, rats or other snakes; if a sleeping person rolls on to them, or if they mistake a hand or foot for a rodent, they bite, and are deadly.)
And a project in Nepal has shown that it isn’t hard to cut snakebite mortality: By training rural paramedics in monitoring snakebites and providing anti-venom; and recruiting local motorcycle owners as volunteer ambulances, the pilot project cut the snakebite death rate from 10 per cent to just 0.5 per cent in five years. The program began in 2003 after research found that 80 per cent of snakebite deaths in villages surveyed occurred outside a medical centre and that half of those victims died on the way to the health facility.
“In many parts of subcontinent you will not find doctors where victims come to – you will find paramedics and health assistants – so you need to empower them to provide first line-treatment. It’s being successfully addressed in Nepal but has yet to spread out over the subcontinent,” Dr. Kuch said.