You didn't see this one coming. But like the perpetrators of this widespread health problem, snakebite slithers onto the list as a condition that affects a surprisingly large number of people.
The WHO's NTD program estimates 421,000 people are envenomed, or bitten by poisonous snakes, each year, with 20,000 dying from the poison. The lack of accurate records in rural areas, however, leads some experts to put those figures much higher: 1.8 million envenomings and 94,000 deaths per year. [source: WHO]
The envenomings are disproportionately frequent in poorer countries, which suffer a double-whammy: Many developing countries are in regions where very poisonous snakes, such as the cobra family, are endemic, and those same regions often lack the infrastructure to get antivenin, an antibody drug that counteracts the venom, to bite victims in time to save their lives [source: WHO].
This is not a simple case of making enough of one drug to treat snakebites around the globe. Antivenin is made by injecting the venom of a specific snake species into a horse or sheep, extracting the antibodies, and then purifying them for human use. The antivenin for a diamondback rattlesnake from the American Southwest, for example, would be useless for a patient bitten by a spectacled cobra in India [source: U of Maryland]. One could argue that, unless lab infrastructure gets much better in developing countries soon, snakebite will be a constant threat for years to come.