Health

Snakes kill more people than either dengue fever or skin cancer, according to a new worldwide estimate.

See an interactive map of the areas affected

Cobras, vipers, black mambas and other venomous snakes take between 20,000 and 94,000 lives each year, and bite another 421,000 to 1,841,000 people.

However, the economic toll of snakebites could be far greater than many infectious diseases, says Janaka de Silva, an epidemiologist at the University of Kelaniya in Ragama, Sri Lanka, who spearheaded the new report.

De Silva is hoping the study will raise the profile of snakebites. "We want to get the snake bite classified as a neglected tropical disease," he says.

His team trolled published papers, national and regional health data, and hospital records to establish a snake bite death rate for 169 countries where attacks are a problem.

Disabling bite

Because snake bite data for many of these countries, particularly in Africa, did not exist, the team extrapolated figures based on data from neighbouring countries, and produced an upper and lower estimate for snake bite victims.

Snakebites were most common in tropical areas, which are generally home to more venomous snakes than temperate regions.

However, increased rural development in many of these countries also fosters more contact between people and snakes. Factor in dispersed healthcare centres with little money to stock anti-venom or other treatments, and you have the makings of an epidemic, de Silva says.

Reliance on traditional treatments can also result in higher death rates in some countries, he says.

And while worldwide snake bite deaths pale in comparison to pandemics such as malaria and HIV, or chronic disease such as cancer, many victims of snakebites suffer physical maiming for the rest of their lives.

"Disability is much higher than in infectious disease," de Silva says. "In infectious diseases you either die or recover."

Journal reference: PLoS Medicine (DOI: 10.1371/journal.pmed.0050218)

If you would like to reuse any content from New Scientist, either in print or online, please contact the syndication department first for permission. New Scientist does not own rights to photos, but there are a variety of licensing options available for use of articles and graphics we own the copyright to.