Your Guide to
Neglected Tropical Diseases

Snakebite envenoming is a life-threatening condition caused by toxins injected when a venomous snake bites a person. The effects vary depending on the type of snake, but can include severe pain and swelling at the bite site, paralysis that prevents breathing, and uncontrolled bleeding, kidney failure, and tissue death that may lead to amputation.

Symptoms typically develop within minutes to hours after a bite, although some effects may take longer to appear. Children are at higher risk of severe effects because of their smaller body size. Not all bites from venomous snakes result in envenoming; dry bites, in which no venom is injected, vary widely by species and setting. However, any suspected venomous snakebite should be promptly treated with antivenom to prevent envenoming death.

Venomous snakes are found on every continent except Antarctica, although most medically important species live in tropical and subtropical regions. The three main families of venomous snakes responsible for the most severe envenoming are vipers, elapids, and sea snakes. Different snake species have different venom types that cause varying effects: some cause paralysis and breathing problems, while others cause severe bleeding or tissue destruction. Snakebites typically occur when people accidentally step on or disturb snakes while working in fields, walking through vegetation, or sleeping on the ground.

Bites often affect the feet and legs, occurring during daytime hours and peak agricultural seasons.

Geographic scope:

• An estimated 5.4 million people are bitten by snakes each year globally, of whom 1.8-2.7 million develop snakebite envenoming.
• Between 81,000-138,000 people die annually from snakebites, with three times as many suffering permanent disabilities including amputations.
• About 95% of deaths occur in Africa, Asia, and Latin America, with the highest burden in South Asia, Southeast Asia, and sub-Saharan Africa.
• India accounts about half of global snakebite deaths.
• Deaths are rare in high-income regions like Australia, Europe, and North America due to better healthcare systems and antivenom availability.
• In Asia, up to 2 million people are envenomed annually; in Africa, 435,000-580,000 people require treatment each year.

Population affected:

• Agricultural workers, herders, fishermen, and hunters are at highest risk, as are people living in poorly constructed housing in rural areas.
• Working children aged 10-14 years are particularly vulnerable.
• Most deaths and disabilities occur among people aged 10-30 years.
• Underreporting is severe: in some areas, over 70% of cases never reach health facilities and go unreported.

Prompt medical care is essential after a suspected venomous snakebite. Traditional remedies and harmful practices like cutting the wound or applying tourniquets should be avoided. Antivenom is the only specific treatment that can prevent or reverse the effects of snakebite envenoming and is included on WHO's List of Essential Medicines. However, access to safe, effective antivenoms is severely limited in most affected regions. Multiple manufacturers have stopped production over the past 20 years, and prices have increased substantially, making treatment unaffordable for many people who need it. In sub-Saharan Africa, safe products are often unavailable. Estimating needs is difficult due to poor data on snakebite cases, creating a cycle of low demand, reduced production, and rising prices.