The World Of Atheris

All vipers are solenoglyphous. Solenoglyphs have completely enclosed hollow fangs attached to the maxillary bone. These fangs, which are replaced periodically throughout the snake's life, are folded into cavities in the roof of the closed mouth and may be erected simultaneously, individually, or not at all during a strike. A strike is more of a stab than a bite, and venom may or may not be injected. The venom is primarily haemotoxic.

Bush vipers are often found in isolated populations far removed from humans and therefore cause very few snakebites. Their venom is poorly studied and there is no available antivenin. Existing antivenin do not neutralize the venom of this genus. However, I have received some anecdotal information that polyvalent Echis serum has been used with success in Atheris squamigera. I have been unable to confirm this and mention it here only to encourage discussion on its merits. Reported symptoms of Atheris bites include pain, swelling, and blood clotting difficulties. Bites from the green bush viper (Atheris squamigera) have caused death. Blood transfusions may be required if poor blood clotting occurs. The case study below illustrates the potential for serious medical emergency event of an Atherini bite.

ANY BUSH VIPER BITE SHOULD BE CONSIDERED EXTREMELY SERIOUS AND POTENTIALLY LIFE THREATENING!

The venom of the Atherini tribe is poorly studied and generally misunderstood. Many herpetoculturists are attracted to the captive husbandry of snakes of the genera Atheris and Proatheris (Adenorhinos and Montatheris are unknown in captivity) due to an erroneous belief that these snakes are 'mildly venomous' or not life threatening. This is simply not true. ALL ATHERINI SPECIES SHOULD BE CONSIDER CAPABLE OF PRODUCING AN FATAL ENVENOMATION IN MAN.

There is scant literature regarding Atherini envenomation, but all Atherini species should be considered capable of a lethal bite and treated with appropriate caution. There have been at least two fatalities caused by the bite of Atheris squamigera and other envenomations have resulted in extremely serious medical emergencies. In 1996, a private herpetoculturist was envenomated by Atheris nitschei while bagging the snake and experienced an extremely serious medical emergency similar to the Proatheris superciliaris envenomation that will be described below. That same year a zoo keeper was bitten on the knuckle by an Atheris chlorechis and experienced a much less severe envenomation. There is currently no antivenin produced for treatment of bites from these species.

The venom of the Atherini species is hemotoxic, or blood affecting. It is known to cause severe pain, abnormalities in coagulation (clotting), and destruction of red blood cells (hemolysis).

The following is the account of a bite from Proatheris superciliaris, the Lowland Viper, and the medical emergency that resulted:

On 24 August 1996, during a routine cage maintenance procedure, a keeper was bitten on the left forefinger by a specimen of Proatheris superciliaris approximately 48 cm (19 in.) in length. He managed to return the snake to its container despite it "striking insanely and undulating during the whole process". He immediately experienced severe pain in his hand which he likened to being splashed by boiling bacon grease. During the next two hours the hand experienced necrosis (cell or tissue death) and ecchymosis (purple discoloration caused by blood entering the subcutaneous tissue from ruptured blood vessels), and became covered with blebs. By then he was hospitalized and morphine had been administered for the pain without success. Over the course of the next two days he went into massive hemolysis (dissolution or destruction of red blood cells with subsequent release of hemoglobin), experienced complete platelet destruction, and his liver and kidneys began to fail due to the overwhelming amount of protein fragments resulting from the destruction of erythrocytes (red blood cells) and platelets. His body turned yellow as a result of the jaundice. A group of leading experts were consulted and there was a belief that he may die due to Hemolytic Uremic Syndrome. They decided he should undergo plasmapheresis, a process in which plasma is removed from blood and the remaining components, mostly red blood cells, are returned to the bloodstream.

Fortunately, this individual survived to describe this incident, but not without suffering extreme pain and undergoing extensive and horrible treatment. His recovery from this envenomation took over six months. He required two surgeries to repair his hand including a cross-flap skin graft. There is some permanent disfigurement to his left forefinger and some reduced mobility. In his words, "I owe those men [the doctors and consultants] my life, my wife was in shreds...a very terrible ordeal for a 'supposedly mildly venomous viper' ".

I would like to offer my sincerest thanks to Adam C. Marfisi for sharing his ordeal. He did so in hopes that as many keepers or prospective keepers as possible would fully appreciate the significant risk that these vipers present.