Saw scaled viper has killed more people than any other venmous snake in the world

Deadliest Snake In The World

Snakes have long since slipped into the human collective unconscious. The potential threat of a pernicious serpent lurking in the weeds or beneath a stockpile of wood would have been a serious cause for concern for our hunter-gatherer ancestors. Modern medicine, combined with a nuanced understanding of the various venoms and temperaments in play, has thankfully lessened the risk of a disastrous encounter. But even still, the World Health Organization estimates that anywhere between 81,000 to 138,000, (while the Global Snakebite Initiative puts the figure at 125,000) people succumb each year as a result of snake bites. The reason for the wide range is because the majority of victims live in remote areas of developing countries, which limits access to anti-venoms and obfuscates the data. But whether on the high or low end of this estimate, snakes are firmly planted as the third-deadliest animal in the world – ahead of dogs but well behind humans and mosquitoes. The single-most serious offender is the saw-scaled viper (Echis carinatus).

Which Is The Deadliest Snake? 

Do not judge a book by its cover, nor a snake by its bite. For even though the saw-scaled viper is small (between 15 to 31 inches, but typically less than 24), and delivers nowhere near as potent of venom as the likes of the inland taipan, the Russel's viper (its cousin from the Viperidae family), or any of the other highly venomous snakes of the world (for which the saw-scaled viper does not even crack the top ten), it is responsible for more human fatalities than any other serpent. It is often the case that highly venomous snakes know they have an ace up their sleeve, and therefore are more reserved and/or elusive. Also, they may only inject a small amount of venom per bite (i.e. sufficient to fell small prey, but not a full-grown human). The saw-scaled viper, on the other hand, has the greatest number of aggressive interactions with people (particularly in India), using its speed and tenacity when threatened (or perceives that it is threatened) to bite its victim repeatedly with a large dose of moderately-potent venom. 

What Happens If A Person Is Bitten By A Saw-Scaled Viper?

saw-scaled viper
Saw-scaled viper

An attack from a saw-scaled viper can yield anywhere from 5 to 48 milligrams of venom, and at an LD50 rating of 0.24 mg/kg – a lethal formula, even at the low end of this range, for humans if left untreated. Though there are nine antivenoms in circulation, they need to be administered within hours after being bitten. But because these snakes thrive in highly-populated but under-serviced regions, there are frequent, untreated, or insufficiently-treated incidents. Ultimately, this creates a scenario in which between 10 to 20% of saw-scaled viper bites result in death due to internal bleeding and kidney failure. 

Unfortunately, death is not the only devastating outcome that can arise from a saw-scaled viper attack. Even if proper medical attention is swiftly sought, administering a targeted antivenom may be inadequate to avoid amputation. This viper's toxic injections cause the afflicted area to swell, bleed uncontrollably, and eventually, necrosis (death and rotting of the tissue) to set in. The large antibodies in artificial antivenoms are unable to move into the impacted tissue – acting instead in a more general, lifesaving manner. For this reason, on top of the roughly quarter of a million annual snake bite deaths, approximately 400,000 additional people face the tragedy of amputation every year. Since the saw-scaled viper delivers the most bites to humans out of any other snake in the world, it is at the top of the most-wanted list for both of these metrics. 

How To Avoid Being Bitten By The Saw-Scaled Viper

When it comes to dangerous snakes, the best line of defense is avoidance. This means knowing their geographical range, standard habitat, appearance, and behaviors. In the case of the saw-scaled viper, healthy populations (classified as "Least Concern" on the IUCN Red List) can be found North of the Equator, in arid regions and dry savannas of Central and Southwestern Asia, the Middle East (Arabia), Africa, Sri Lanka, and especially India. These snakes have short but fairly stout bodies, pear-shaped heads, a short, rounded snout, elliptical pupils, and rough, keeled scales. 

When threatened, the saw-scaled viper coils together tightly, rubbing (or rather, "sawing") its scales to produce a sort of sizzling sound. If this warning is not heeded, it can lash out at an alarming speed, even using a rapid and intimidating sidewinding motion (that is well-suited to traversing sandy environments) to pursue its target. 

This species is generally nocturnal or crepuscular (i.e. active at dawn/dusk), hunting small creatures such as rodents, lizards, frogs, and insects. Saw-scaled vipers are especially energized on humid evenings, so pay extra mind after it rains, particularly around bushes and small trees. During the day, these snakes tend to retreat to existing animal burrows, rock fissures, and fallen logs, and if in a sandy setting, they will bury their bodies but leave the head exposed. Saw-scaled vipers living in the Northernmost reaches of the known territory will hibernate during the winter. 

If you find yourself living in the same regions as saw-scaled vipers, be aware of your movements, wear protective gear if working outside (such as high-cut boots and gloves), and try to have a plan in place in case of an attack. As always, should a bite occur, remain calm and seek medical attention immediately. 

There are over 3,000 species of snakes on this planet. Of those, approximately 600 are venomous, and 200 have a bite that is potent-enough to be lethal to humans. But most that are theoretically capable of killing us rarely do so because of their propensity for solitude and focus on small prey. Even if an unlucky person is struck by a venomous snake, the injected dose is often modest and treatable. However, of all these fear-inducing, slithering creatures, the saw-scaled viper is undeniably deadly. It pales in comparison to the likes of the king cobra in terms of appearance, but aggressive encounters are common, and bites of any kind are devastating, or outright lethal (as is the case in upwards of 1 in 5 scenarios). 


More in Nature