Snakebite envenoming is a potentially fatal but largely undercounted public health crisis, especially in poor, rural communities across tropical and subtropical regions. Researchers who analyzed data from 79 countries estimate that at least 2.1 million people experience snake poisoning each year, with the true figure potentially reaching 7 million. Annual deaths may range from 274,000 to 513,000, while sub-Saharan Africa bears the greatest burden.
Not every snakebite injects venom. But when venom enters the body, it can cause severe illness, disability or death. Many victims in rural areas of sub-Saharan Africa and South Asia live hours from the nearest clinic, lack transportation or seek help from a traditional healer. Their cases often never appear in national health statistics.
Researchers with decades of experience in the epidemiology of snakebites and tropical diseases say this has created a major data crisis. More than half of the countries affected by venomous snakes do not know how many people are bitten or poisoned each year.
Estimating the hidden burden
To address the gap, the researchers conducted a study mapping the global burden of snake venom and associated deaths. They reviewed research from 79 countries published up to March 31, 2025, updating the findings of the 2008 Global Burden Survey.
They also built a geostatistical model to estimate poisoning and mortality rates in places where reliable records were unavailable. The analysis combines observed health data with environmental and socioeconomic factors, allowing researchers to estimate risks even when official records are incomplete or absent.
The model incorporated factors including climate, the abundance of snake species and socioeconomic indicators. It calculated the probability of a snakebite occurring in a particular location, then compared sources such as hospital reports and local statistics with community survey data.
This approach accounts for underreporting and produces both lower and potential upper estimates for snakebite envenoming and deaths. The results suggest that at least 2.1 million people worldwide experience snake poisoning each year. The actual number could be as high as 7 million.
After adjusting for substantial underreporting, the researchers estimated that annual deaths could range from 274,000 to 513,000. The geographic distribution is uneven: sub-Saharan Africa accounts for an estimated 45% of global poisonings and deaths, a burden that has probably been underestimated for decades.
People in sub-Saharan Africa experience snake poisoning and death at nearly three times the rate recorded in South Asia. Countries including Nigeria, the Democratic Republic of the Congo and Ethiopia are among those facing a particularly heavy burden because of rural population density and high exposure among agricultural workers.
Why sub-Saharan Africa is hardest hit
The region’s disproportionate impact is driven by structural conditions rather than chance.
Sub-Saharan Africa is home to a wide range of medically important venomous species, including saw-scaled vipers (Echis spp.), puff adders (Bitis arietans), African cobras (Naja spp.) and mambas (Dendroaspis spp.). These snakes cause substantial illness and death across the continent.
Millions of rural agricultural workers also work in fields without protective footwear and walk along unlit paths at night. When a bite occurs, a treatable medical emergency can quickly become fatal because of weak healthcare systems, long journeys to medical facilities, high treatment costs or a lack of effective antivenom. Similar problems affect parts of Asia.
The researchers estimate that more than 800,000 people survive snake envenoming each year with long-term disabilities, including amputations and other permanent impairments. These injuries can reduce household incomes, increase healthcare costs and push already vulnerable farming families further into poverty.
Using data to guide prevention
The World Health Organization has set a goal of halving snakebite-related mortality and disability by 2030. The researchers say mapping the problem at country level is an important first step toward achieving it.
Identifying high-risk areas could help governments and global health organizations stockpile antivenoms where they are most needed, train primary healthcare workers in high-burden rural communities and improve emergency transport infrastructure.
Better data alone will not solve the snakebite crisis. But it can help ensure that antivenoms, healthcare services and prevention efforts reach the communities that need them most.
Source: www.sciencedaily.com
