The venom from snake bites kills approximately 30,000 people in sub-Saharan Africa each year. In an attempt to significantly lower this figure, scientists at the Liverpool School of Tropical Medicine (LSTM) have recently begun research into a universal snake bite anti-venom, the first of its kind, using a new technique called ‘antivenomics’. If successful, the anti-venom will work against bites from all 20 species of deadly snakes in the sub-Saharan region.
Researchers plan to produce a single, affordable and non-cold chain snake bite anti-venom, to which a stabiliser will be added to allow the product to be stored effectively in the high temperatures of Africa. The antivenomics method will increase the potency of venom extraction, which has traditionally had a low success rate.
Dr Robert Harrison, the head of LSTM’s Alistair Reid Venom Unit, told the BBC: “Not only do we expect that our anti-venom will be cheaper, and safer, and much more effective than anything else, but it will be able to be used anywhere south of the Sahara. That combination of factors makes it unique. These snakes are contributing to the basic resource for a brand new medical product.”
The research is funded by the Medical Research Council and will collaborate with the Instituto Clodomiro Picado, San Jose, Costa Rica and the Institute de Biomdedicina de Valencia, Spain on the project. The LSTM houses more than 400 snakes, from which up to 80 a week will have their venom milked for the research.
This milking occurs by holding the snake’s head over a beaker as venom squirts from their fangs. From this, proteins are removed and the venom diluted. The resulting compound is then injected into animals (usually horse, sheep, rabbits or goats) who produce anti-bodies to the venom. These anti-bodies are harvested from the animal and used to produce the snake bite anti-venom.
Doctors treating a snake bite patient often have to rely on their description of the snake to ensure they use the correct treatment. Those who survive a snake bite often face further complications – each year around 96,000 people in the region encounter permanent disabilities after receiving treatment for snake bite envenoming.
“The preferred option, therefore, is to give a broad-spectrum, or poly-specific, snake bite anti-venom to cover all the possible snake species that could be responsible,” claims Dr Harrison. Because these treatments are generally not very effective against any one species due to their weakness, doctors often administer many vials. However, each dose carries a risk of serious side effects and this risk increases with each additional vial. By creating a more potent anti-virus, the LSTM hopes to not only save thousands of lives each year, but also limit the chances of those who survive from experiencing side effects from their treatment.
According to WHO, anti-venoms are unusual among pharmaceutical agents, in that they have been used in human patients for more than 100 years with little attention paid to clinical trials for their efficacy and safety. However, in recent decades it has been proved possible to carry out dose-finding and randomised controlled trials in human victims of snake bite envenoming.