An injury caused by a snake, the term usually referring to a bite from a venomous snake. Venomous snakes use venom primarily to subdue prey and secondarily in self-defence. Most envenomation results from treading on, handling, or passing very close to and appearing to threaten a snake. Every year, according to the World Health Organization, snakes bite about five million people worldwide, of whom more than 100,000 die and up to 400,000 suffer amputations and permanent disfigurement. Snakebite can usually be treated, but there is a world shortage of antivenom.