Elapidae envenomation

Presynaptic snake neurotoxins endowed with PLA2 activity (SPANs) are major components of the venom of four families of venomous snakes (Crotalidae, Elapidae, Hydrophiidae, and Viperidae). These neurotoxins play a crucial role in envenomation of the prey (Harris 1997) by causing a persistent blockade of neurotransmitter release from nerve terminals with a peripheral paralysis very similar to that of botulism (Connolly et al. 1995 Gutidrrez et al. 2006 Kularatne 2002 Prasampun et al. 2005 Theakston et al. 1990 Trevett et al. 1995 Warrell et al. 1983). 

This family includes coral snakes, cobras, mambas, and kraits. In the United States, Elapidae are responsible for 1-2% of poisonous snakebites. The incidence of envenomations is greater in some other parts of the world. Examples of coral snakes commonly found in the United States are the eastern coral snake, the Sonoran coral snake, and the Texas coral snake. Coral snakes are smaller than pit vipers. They do not have facial pits, and the head is rounded, as are the pupils. Eangs are 2mm and fixed to the jaw. Coral snakes are also more brightly colored, with bands of black and red, separated by yellow and white bands. Coral snakes are timid, nocturnal creatures. 

Systemic absorption of Elapidae venom is dependent on lymphatic transport following subcutaneous envenomation. The onset of neurotoxic symptoms usually occurs within 4h but can be delayed up to 10 h following a bite. The metabolism of venom components is not well understood. It is likely that venom components are inactivated by enzymes within tissues where the venom is ultimately distributed. The distribution of venom is variable and complex and possibly reaches different tissue sites unevenly. The biological half-life of Elapidae venom has not been determined. It is likely that metabolized venom fractions are eliminated primarily by the kidneys. 

Elapidae Micrurus Naja Bungarus Dendroaspis Coral snake Cobra Krait Mamba Human envenomation difficult because of small mouth and small fixed fangs in rear of mouth. Neurotoxicity usually predominates. 

B. Elapidae. Coral snake envenomation is rare because of the snake s small mouth and fangs. The snake must hold on and chew the extremity for several seconds or more to work its fangs into the skin. 

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