The report says that the true magnitude of the problem is not known
South Asia has the highest number of casualties from snake bites in the world, a new study suggests.
It found that more than 400,000 people a year are poisoned by snake bites worldwide, with 20,000 deaths annually.
The research published by the US based Public Library of Science Medicine involved data from 68 countries.
India, with its population of over a billion people, accounted for the highest estimated number of bites and deaths for a single country.
Researchers led by Janaka De Silva at the University of Kelaniya in Sri Lanka say that conservative estimates suggest 421,000 cases of "envenoming" - or venom released through biting - occur each year, with 20,000 people dying as a result of being poisoned by snake bites.
India had the highest number of people poisoned - just over 80,000, resulting in 11,000 deaths - followed by Sri Lanka with 33,000 people poisoned. Most victims are male.
Researchers say the numbers could be higher because many snakebites are not reported - especially in rural areas where many victims do not have access to good health care and rely on traditional remedies.
"The fact that snakebite varies geographically and seasonally, that it is mainly a rural tropical phenomenon where reporting and record keeping is poor and that health-seeking behaviour is diverse with traditional treatments being sometimes preferred to Western medicine, all contribute to the difficulties faced when studying its epidemiology," the report says.
"The true magnitude of the public health threat posed by snakebites in these countries (and elsewhere in the world) is unknown, which makes it hard for public health officials to optimise the prevention and treatment of snakebites in their respective countries."
Of the 3,000 or so snake species that exist in the world, the report says, about 600 are venomous. They exist on every continent except Antarctica.