Most<unk>  are caused by non-venomous snakes. Of the roughly 3,700 known species of snake found worldwide, only 15% are considered dangerous to humans. Snakes are found on every continent except Antarctica. There are two major families of venomous snakes, Elapidae and Viperidae. Three hundred twenty five species in 61 genera are recognized in the family Elapidae and 224 species in 22 genera are recognized in the family Viperidae, In addition, the most diverse and widely distributed snake family, the colubrids, has approximately 700 venomous species, but only five genera—boomslangs, twig snakes, keelback snakes, green snakes, and slender snakes—have caused human fatalities. Since reporting is not mandatory in many regions of the world,<unk>  often go unreported. Consequently, no accurate study has ever been conducted to determine the frequency of<unk>  on the international level. However, some estimates put the number at 1.2 to 5.5 million<unk> , 421,000 envenomings, resulting in perhaps 20,000 deaths, but the actual number of deaths may be as high as 94,000. Many people who survive bites nevertheless suffer from permanent tissue damage caused by venom, leading to disability. Most snake envenomings and fatalities occur in South Asia, Southeast Asia, and sub-Saharan Africa, with India reporting the most<unk> deaths of any country. An analysis cross-referencing exposure to venomous snakes and accessibility of medical treatment identified that 93 million people worldwide are highly vulnerable to dying from<unk>  Worldwide,<unk>  occur most frequently in the summer season when snakes are active and humans are outdoors. Agricultural and tropical regions report more<unk>  than anywhere else. In North America, the victims are typically male and between 17 and 27 years of age. Children and the elderly are the most likely to die. + Number of<unk> Envenomings per Year Region Low Estimate High Estimate Asia 237,379 1,184,550 Australasia 1,099 1,260 Caribbean 1,098 8,039 Europe 3,961 9,902 Latin America 80,329 129,084 North Africa / Middle East 3,017 80,191 North America 2,683 3,858 Oceania 361 4,635 Sub-Saharan Africa 90,622 419,639 Total: 420,549 1,841,158 + Number of Deaths from Envenoming per Year Region Low Estimate High Estimate Asia 15,385 57,636 Australasia 2 4 Caribbean 107 1,161 Europe 48 128 Latin America 540 2,298 North Africa / Middle East 43 78 North America 5 7 Oceania 227 516 Sub-Saharan Africa 3,529 32,117 Total: 19,886 93,945
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