Snake bites
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A common question that many people wonder about when they travel to the tropics is; what exactly happens when I get bit by a snake? Well, you don’t necessarily die, that’s for sure! It really depends on the species of snake you’ve been bit by. You see, venom is so complex that even the professionals don’t always know what’s gonna happen. Snakebite is one of the most unpredictable medical emergencies in the world. The local acting venoms often cause the breakdown of your connective tissue and blood vessel walls. Swelling may be so severe that blood flow is completely cut off, causing oxygen deprivation of that part of your body with the risk of necessary amputation. The systemic acting venoms attack your nervous system; they inhibit the conduction of nerve impulses, leading to muscular paralysis and inability to breath. The venom may cause blood to coagulate more rapidly or not coagulate at all, leading to either the formation of blood cloths or bleeding. Then there are many other toxins that can cause blood vessel dilation or constriction, and increased or decreased sensitivity to pain, among many others. And the fact of the matter is, all these symptoms can occur simultaneously in many given species of snake. So you see, it’s quite a complex thing! But YOU SHOULD ALWAYS GO TO A HOSPITAL AFTER SNAKEBITE! A recent article in the prestigious scientific journal Plos Medicine stated: "Unfortunately, public health authorities, nationally and internationally, have given little attention to this problem, relegating snake bite envenoming to the category of a major neglected dissease of the 21st century"1. Each year, probably around 150.000 people die because of snake bites2, although the exact number is difficult to specify because many do not seek medical care, it might be more. Local villagers choose traditional medicine above modern science as treatment, so many bites will go unregistrated3,4. In any case, considering the numbers, snake bites are not to be neglected. Especially in Afirca, Asia and Latin America snakebites form a big problem. Within these countries, each year more then 100 people per 100.000 people die through a snakebite. The highest number has been found to be in Asia, East Terai of Nepal, were 162 people die through a snake bite per 100.000 people per year5. In Nigeria (Africa) the incidence of snake bites was found to be 497 per 100.000 people per year, with a mortality rate of about 12.2%6. Still, snakes are not evil creatures that are set out to bite and kill people. On the contrary, they first prefer to flee, before attack. Even with attack, about half of all snake bites do not result in envenomation, the so called 'dry bites'. Snakes are very economic with their precious venoms. Unless they feel life threatened. Importantly, about 97% of people bitten by snakes survive without any severe damage. So, if one is bitten by an unkown snake, this should be kept in mind so that one does not panic. The main first aid measure that can be used is the Pressure Immobilization Bandage, although the effectiveness of this treatment is currently under discussion. It was developed by the late Prof. Sutherland in 1979 (ref. 7). If applied properly, it will slow down or completely stop the flow of lymph. The lymphatic system drains away fluid from the tissues and returns it to the bloodstream. It is the main route of venom into the bloodstream in most cases – unless the snake bite injected venom directly into a blood vessel. It should be applied immediately after the bite. The series of figures below are copyright of the Australian Venom research Unit.
1. Gutierrez,J.M., Theakston,R.D. & Warrell,D.A. Confronting the neglected problem of snake bite envenoming: the need for a global partnership. PLoS. Med. 3, e150 (2006) |
