Cushioned in our urban bubble, the realities of snake bites are far removed from our world, but a shocking 46,000 Indians die every year from preventable conditions as consequences of a bite. The truth is that most snakes offer no harm to humans; we’re unlikely to run into the most deadly ones. Even if we do, they never inject enough venom to cause serious damage. But in rare situations, we encounter potent venom so destructive that it can break down membranes, prevent blood from clotting and lead to intense internal bleeding.
In India, around 2.5 lakh cases of snake bites are reported every year, which is shocking because India is not home to the largest number of snakes and there is no shortage of anti-venom available. Most people who survive being bitten on the stop end up losing the battle due to the delay in reaching a nearby hospital or a lack of treatment, often due to an overdose of anti-venom. However, University of Mysore’s Kempaiah Kemparaju and his colleagues, Gajanan Katkar and Kesturu Girish, have found a solution to this growing problem.
The team began studying the immune system to see how it would react to viper venom when white blood cells were deployed. They discovered that some of the cells, known as macrophages, would damage tissue, and so began isolating them. In the process, they found another type of white blood cell, called the neutrophil. Neutrophils kill microbes by “bursting open and releasing a tangled mesh of their own DNA,” according to Nat Geo. This mesh is loaded with antimicrobial molecules, which kill hostile cells — they’re often called NETs, or neutrophil extracellular traps.
But when Kemparaju and his team saw the DNA threads under a microscope, they realised that NETs were being released in the presence of viper toxins, where they did a lot more harm than good. “This mesh traps venomous toxins and blocks blood vessels, and attack the tissues at the site of the bite. Those tissues quickly die from lack of oxygen. This was tested in rodents with low levels of neutrophils, which died quickly with venom but didn’t suffer tissue damage. You are left with a grim choice; either let the venom take over the body and kill outright, or focus it to one area and have it damage the entire limb physically. Instead of life, you give your limb,” adds Kemparaju. However, if the team waited for an hour or two before injecting the DNase (a DNA enzyme), they prevented tissue damage without reducing a chance of survival. “With our mice, we have achieved 100 percent success,” says Kemparaju to Nat Geo. “Even if you administer the DNase three hours after the venom, you can prevent the loss of limb.”
These results are very exciting, especially considering the far reaching effect it can have on our nation where snake bites still pose a very huge problem. In a piece titled ‘Why does India have so many snakebites?’ world-renowned herpetologist Rom Whitaker postulates that most of the people affected by snake bites are farmers and labourers in the agriculture sector, where they often get into fields without footwear and walk in the darkness without using a light. This new development can help them prevent fatalities, and perhaps even curb real physical damage.