A Green Mamba bite is a serious medical event, as these snakes are highly venomous. The two primary species are the Eastern Green Mamba (Dendroaspis angusticeps) and the Western Green Mamba (Dendroaspis viridis). Both are slender, fast-moving, tree-dwelling snakes native to sub-Saharan Africa. Although these arboreal snakes tend to be shy and avoid human contact, their powerful venom requires immediate medical attention following any bite. Understanding the nature of the venom and the resulting symptoms is necessary for a rapid and effective response.
The Nature of Green Mamba Venom
The venom of the Green Mamba is a fast-acting, complex mixture dominated by neurotoxins, which target the victim’s nervous system. These neurotoxins include dendrotoxins and a high concentration of proteins from the three-finger toxin family, which interfere with normal nerve signaling. Dendrotoxins block specific potassium channels in nerve cells, leading to an over-release of acetylcholine, the neurotransmitter responsible for muscle contraction. This initial nerve overstimulation is rapidly followed by a severe blockade of nerve-to-muscle communication at the neuromuscular junction.
The venom also contains fasciculins, which inhibit the enzyme acetylcholinesterase, further disrupting normal nerve function. This neurotoxicity is the primary and most life-threatening component, quickly progressing to muscle paralysis. Green Mamba venom also contains cardiotoxic elements that can directly affect heart muscle tissue, contributing to systemic effects.
The venom of the Western Green Mamba is considered more potent than that of the Eastern Green Mamba, though both are medically significant and potentially lethal. The toxicity is due to the synergistic action of the various components. The speed of the venom’s action is a distinguishing trait of all mamba species, with symptoms manifesting rapidly after a strike.
Recognizing the Signs of a Bite
Symptoms following a Green Mamba bite can begin to manifest extremely quickly, often within 15 minutes of the strike. The first local effects at the bite site are typically pain and mild swelling. This seemingly mild local reaction can be deceptive, as the systemic effects of the neurotoxins begin to take hold almost immediately.
As the venom spreads, the victim may experience systemic symptoms such as dizziness, headache, nausea, and difficulty swallowing. The neurotoxic effects then progress to impair the function of various muscle groups, beginning with the muscles controlling the eyes and face. A characteristic sign of neurotoxicity is ptosis, or the drooping of the eyelids, often followed by slurred speech and difficulty controlling the tongue.
The progression of symptoms is descending, meaning the paralysis starts in the head and neck and moves downward through the body. Difficulty breathing is a serious sign that the paralysis is affecting the respiratory muscles. Without immediate medical support, this paralysis will lead to respiratory failure as the diaphragm and chest muscles cease to function.
Essential Steps for Emergency Response
The first step following a suspected Green Mamba bite is to seek professional medical attention immediately. The rapid action of the venom means that transportation to a facility that stocks the correct antivenom must be the priority. The patient should be kept as calm and still as possible, as movement or panic can accelerate the spread of the venom throughout the body.
The bitten limb should be immobilized using a splint or sling and kept at a neutral level, ideally below the level of the heart, if possible. A pressure immobilization bandage, a firm but not restrictive wrap, can be applied to the entire limb to help slow the lymphatic spread of the neurotoxins, though this should not delay transport. Removing any tight clothing or jewelry from the affected area is also necessary before swelling begins.
It is imperative to avoid traditional first-aid measures, as they can cause further harm. This includes:
- Not cutting the wound.
- Not attempting to suck out the venom.
- Not applying a tourniquet.
- Not applying ice to the area.
Once the victim is at a medical facility, the definitive treatment is the administration of a polyvalent antivenom designed to neutralize mamba venom. Due to the risk of respiratory muscle paralysis, medical personnel must be prepared to provide mechanical ventilation and respiratory support until the antivenom takes effect.