Thousands of lives at risk from snake bites as doctors warn antivenom is running dry

8 Sep

Snake bite is one of the deadliest, most common, most curable and most neglected health risks in the world. Now, the only safe and effective weapon against sub-Saharan snake bites – the antivenom Fav-Afrique – is in danger of disappearing, according to Médecins Sans Frontières/Doctors Without Borders, posing a risk to countless lives.
[Cobra snake]
Around 5 million people around the world are bitten by snakes every year, of whom 1 in 10 will die or be left with permanent disabilities.

Around 5 million people around the world are bitten by snakes every year, of whom 1 in 10 will die or be left with permanent disabilities, according to Médecins Sans Frontières/Doctors Without Borders (MSF).

Snake bites kill up to 100,000 people annually and disfigure approximately 400,000, many of whom are children, and most of them from poor, remote and rural areas.

Snake bite antivenom saves thousands of lives every year; but Fav-Afrique – the key player – is due to run out and not be replaced, at least for some time.

Fav-Afrique depends on production of equine serum immunized with venom from 10 of the most dangerous snake species in Africa. This means that a single serum can be used to treat bites from 10 different and extremely poisonous snakes.

Last batch of Fav-Afrique will expire in June 2016

Fav-Afrique works by decreasing the quantity of circulating venom, and therefore its toxicity. It has so far been the most trusted and effective snake antivenom, and with good snake antivenoms being hard to come by, it should be considered a precious commodity.

However, Sanofi, its producer, stopped making it in 2014, and the last batch of the product will expire in June 2016. Negotiations are under way to transfer the technology to another company, but these are not expected to be completed until the end of 2016, which means that the product will not be available until late 2018 at the earliest.

Snake antivenoms are expensive and difficult to produce and mainly used by the poor. They can cost $250-500 per victim, approximately 4 years salary for many. They can also be difficult to store if refrigeration facilities are not available. Commercial producers, governments and organizations find it hard to see its cost-effectiveness. Funding agencies do not list it as a priority, yet fatality rates are significant.

The production of hyperimmune equine serum, used as a basis for antivenom, is now seen as outdated, with the result that most drug companies have stopped making it. The next generation of treatment, monoclonal antibodies (mAbs), is not yet considered mature enough to fill the gap. Global capacity to produce and purify equine plasma is limited, but demand remains high.

Sanofi continue to run a hyperimmune equine facility, but they have turned the lab over to rabies serum, which is another neglected product. MSF would like to see more companies manufacturing hyperimmune equine serum to meet the global demand.

While snake antivenom is produced by companies in India and Mexico, among others, there is limited evidence of its effectiveness. Most either treat the bite of just one species or trial data is lacking, both of which contribute to a lack of cost-effectiveness in the long run.

Snake bite envenoming ‘has been neglected for far too long’

MSF blame the current situation on lack of awareness and failure to prioritize the issue. They point out that the World Health Organization (WHO) currently do not have a specialist in this field, and that both information and the will to act are seriously lacking on all levels.

According to MSF:

“Snake bite envenoming is an issue that has been neglected for far too long […]. Global health agencies, donors, governments and pharmaceutical companies […] share responsibility for putting it back where it belongs on the global health agenda, and taking immediate and collaborative action to address this major public health emergency.”

Meanwhile, the Centers for Disease Control and Prevention (CDC) estimate that 7,000-8,000 people per year receive venomous bites in the US, and about five of those people die. The comparably high survival rate in the US is attributed to the availability access to medical facilities.

Written by Yvette Brazier

Copyright: Medical News Today

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