Snakebite may be killing far more people than anyone realized.
A new PLOS Medicine study estimates that venomous snakebites cause 2.1 million to 7 million cases of envenoming each year and 274,000 to 513,000 deaths. Envenoming means that injected venom causes clinical illness; not every snakebite does. Even the study’s lowest death estimate is roughly twice the upper end of the World Health Organization’s current estimate of 81,000 to 138,000 deaths a year.
The reason for this undercount is that across much of Africa and Asia, many victims are never counted at all.
They die before reaching a hospital. Many seek treatment from traditional healers who lack knowledge of modern medicine, let alone any antivenom. Many of the undercounted victims live in rural places where surveillance barely exists. And, for years, these missing cases have made the global snakebite crisis look much smaller than it may actually be.
“Our study suggests that previous burden estimates may have substantially underestimated the scale of the problem,” the authors said in a press statement.
Counting the people who never reach the count
Dileepa Ediriweera of the Liverpool School of Tropical Medicine and the University of Kelaniya in Sri Lanka, Anuradhani Kasturiratne of the University of Kelaniya, and their colleagues reviewed snakebite research published from 2007 through March 2025. After screening nearly 4,000 papers and book sections, they retained the most relevant 84 scientific publications and six government or public-health sources.
They then combined country, regional, hospital and community-survey data with information on climate, urbanization, inequality, population and the distribution of medically important snakes. Community surveys consistently produced higher estimates than national databases or hospital records — exactly what one would expect if many victims never reached the formal health system.
Rather than produce a single number, the researchers built two plausible scenarios for undercounting.
For most low- and middle-income countries, the lower estimate assumes hospital records miss some cases, so the model partially corrects for underreporting. The higher estimate assumes community surveys give a better picture of the true burden because they can capture people who never reach hospitals. High-income countries were treated differently because reporting is generally more complete.
So, the study’s 2.1 million to 7 million envenoming cases don’t represent a statistical confidence interval. It is the difference between a relatively conservative correction for missed cases and a much more aggressive one.
The data gaps remain enormous. Of 170 countries with venomous snakes, 91 lacked robust data on envenoming and 100 lacked robust mortality data. About 30 percent of the estimated envenoming burden and 39 percent of the mortality burden came from countries without direct empirical data.
Africa emerges as the center of the crisis
Sub-Saharan Africa accounts for roughly 45 percent of both global envenomings and deaths, with an estimated incidence nearly three times that of South Asia — a pattern the authors say previous estimates had not identified.
India still has the largest absolute burden, with an estimated 409,000 to 1.38 million envenoming cases and 37,600 to 70,100 deaths a year. But high rates spread across much of sub-Saharan Africa. Twenty countries account for about three-quarters of all envenoming cases. And twenty countries account for about 78 percent of deaths.
That represents a striking revision from the influential 2008 PLOS Medicine analysis by some of the same researchers, which estimated 421,000 to 1.84 million envenomings and 20,000 to 94,000 deaths annually.
Yet the new figures come with important cautions. Community surveys often take place in known snakebite hotspots, which can inflate national extrapolations. Hospital data miss people who never arrive. And in countries without observations, spatial models must borrow information from neighboring places that may differ in ecology or health care. The authors explicitly warn against treating individual-country predictions as precise counts.
A harder target for 2030
The WHO classified snakebite envenoming as a neglected tropical disease in 2017 and later adopted a strategy to cut deaths and disability by 50 percent by 2030. If the new baseline is closer to reality, that target starts from a much larger toll than planners assumed.
The model also hints at why the burden falls so unevenly. Greater urbanization predicted fewer envenomings, while higher gender inequality predicted more envenomings and deaths. Greater numbers of medically important snake species predicted higher mortality. The authors caution that these relationships are predictive, not proof of cause; they probably capture deeper differences in poverty, exposure, health systems and access to antivenom.
And death is only part of the damage. The study did not directly measure chronic disability, but using an earlier assumption that permanent physical disabilities occur at roughly three times the number of deaths, the researchers estimate at least 825,000 cases of severe physical disability each year — before counting the chronic psychological harm that can follow a snakebite.
