The puff adder is by far the best known of SA’s venomous snakes, and if you search the internet for “snake responsible for the most snakebite deaths in Africa,” it comes up first. It is also known as the snake responsible for the most serious bites in southern Africa.
However, both these statements are actually incorrect, and they are not the only myths about the puff adder. It supposedly only strikes backwards — an impossible feat if you look at the fang structure of any adder. Adder fangs are large, hinged and recurved, and fold back against the roof of the mouth when the mouth is closed.
The puff adder is certainly one of the fastest striking snakes in Africa. The mouth opens wide, the fangs are swung forward and darted into the prey. The fangs are very large and can exceed 2cm in length.
Puff adder venom, like that of the Mozambique spitting cobra, is potently cytotoxic, causing immediate pain, swelling and in many cases, large blisters, discolouration at the site of the bite and necrosis. Most of the damage is done around the bite initially, but spreads gradually.
There is usually ample time to get to a hospital, but delayed treatment generally results in more serious tissue damage. Although some bites cause severe damage that may even lead to amputation of the affected limb, bites from the puff adder are seldom fatal.
Polyvalent anti-venom that neutralises the venom of most of SA’s dangerous snakes is effective against puff adder venom and, if administered soon after the bite, may prevent tissue damage.
The puff adder is widely distributed throughout southern Africa and further northwards through much of sub-Saharan Africa, but is absent from most of the greater Johannesburg area and central Lesotho. It may be very common in certain areas, but despite its abundance and wide distribution, this snake bites relatively few people. More people are bitten by the spitting cobra than by the puff adder.
Like most of our adders, the puff adder is an ambush hunter that hides in suitable habitat and awaits its prey while in a coiled up and striking position. It is largely active at night and at times these snakes, mainly males in search of females, can be seen crossing roads. But most of the time it is in camouflage mode and coils up under a shrub or in grass where it is almost impossible to see.
While doing research on puff adder behaviour in the Dinokeng Reserve north of Pretoria, Prof Graham Alexander of the Animal, Plant and Environmental Science faculty at Wits University made some amazing observations. While tracking puff adders with implanted radio transmitters, he frequently stood on the snakes by accident, because they were so well camouflaged. But the snakes did not hiss, move or strike at him.
A number of experiments were conducted, during which the snakes were deliberately stood on (using a gumboot) and if the snakes were in a resting or ambush position, none tried to bite. It was only the puff adders that were busy, moving from one place to another, that they took on the well-known defensive behaviour of hissing and striking. So it is possible that if you are a regular hiker, you have already trodden on a puff adder and been none the wiser!
In the event of a puff adder bite, there is little first aid that can be done, other than quickly and safely transporting the patient to the nearest trauma unit. Forget about tourniquets and pressure bandages, or cutting around the fang punctures to suck out the venom. These measures simply don’t work and can only make things worse.
Immobilise the patient and elevate the affected limb just above the heart – this reduces pain – and get to a hospital.
Polyvalent anti-venom is effective against the puff adder bite and the sooner it is administered (if required) the better, but leave the decision to the doctor.
Bear in mind that the majority of snakebite victims that are hospitalised do not receive anti-venom, as such treatment depends on the severity of the bite. Doctors will monitor the subsequent symptoms before deciding on whether to administer it. Less than 20% of snakebite victims that are hospitalised are given anti-venom. – Johan Marais