In Africa, it is mambas, Egyptian cobras, puff adders, and carpet vipers. In the Middle East, it is carpet vipers and elapids. In Latin America, it is snakes of the Bothrops and Crotalus types, the latter including rattlesnakes. In North America, rattlesnakes are the primary concern, and up to 95% of all snakebite-related deaths in the United States are attributed to the western and eastern diamondback rattlesnakes. In South Asia, it was previously believed that Indian cobras, common kraits, Russells viper, and carpet vipers were the most dangerous; other snakes, however, may also cause significant problems in this area of the world. Pathophysiology
Since envenomation is completely voluntary, all venomous snakes are capable of biting without injecting venom into a person. Snakes may deliver such a "dry bite" rather than waste their venom on a creature too large for them to eat, a behaviour called venom metering. However, the percentage of dry bites varies among species: 80 percent of bites inflicted by sea snakes, which are normally timid, do not result in envenomation, whereas only 25 percent of pit viper bites are dry. Furthermore, some snake genera, such as rattlesnakes, significantly increase the amount of venom injected in defensive bites compared to predatory strikes.Some dry bites may also be the result of imprecise timing on the snakes part, as venom may be prematurely released before the fangs have penetrated the person.
Snakebite as a surreptitious form of murder has been featured in stories such as Sir Arthur Conan Doyles The Adventure of the Speckled Band, but actual occurrences are virtually unheard of, with only a few documented cases. It has been suggested that Boris III of Bulgaria, who was allied to Nazi Germany during World War II, may have been killed with snake venom, although there is no definitive evidence. At least one attempted suicide by snakebite has been documented in medical literature involving a puff adder bite to the hand. Research
In 2018, the World Health Organization listed snakebite envenoming as a neglected tropical disease. In 2019, they launched a strategy to prevent and control snakebite envenoming, which involved a program targeting affected communities and their health systems. Other animals
Several animals acquired immunity against venom of snakes that occur in the same habitat. This has been documented in some humans as well. References
Bibliography

Further reading
External links
WHO Snake Antivenoms Database
Organization (2016). Guidelines for the management of snakebites. Regional Office for South-East Asia, World Health Organization. hdl:10665/249547. ISBN 9789290225300.