A matrix against snakebites

Around the world, snakes are both feared and worshipped. India’s ancient Nagas, gods in the shape of serpents, both bestow wisdom and poison rivers. The serpent in the Bible awoke man’s thirst for knowledge and, in doing so, caused the fall from paradise. In West African religion, the snake god Danh-gbi is a life-giver, but his merciless wrath also brings doom and destruction.

Man’s relationship to snakes, legendary or real, has always been a troubled one. With nearly half a million snakebites occurring every year, a significant proportion of which are fatal, the issue now counts as a neglected tropical disease.

If snakebites are the creature’s vengeful side, the snake’s connection with wisdom finds its best modern equivalent in ongoing research efforts to tackle the problem. The latest successful research result is the creation of a new polyvalent antivenom for the hump-nosed pit viper, a snake that haunts the forests of Sri Lanka.

The antivenom, tailored to Sri Lanka’s specific needs, with support from scientists in Costa Rica, illustrates what is becoming painfully apparent — that only a dedicated international matrix can deal with snakebites, an ancient scourge that continues to kill large numbers of people in the developing world.

For long, Sri Lanka had relied on imports of polyvalent antivenom from India, but this was found ineffective against the hump-nosed pit viper, which accounts for most snakebite cases in the island country.

The new antivenom, created from venom drawn from Sri Lankan snakes, also performs better than imports when treating envenomation by two other important viperids, the Russel’s viper and the saw-scaled viper.

The clinical manifestation of snakebite poisoning varies according to the region where the bite occurred, the season, as well as the age, gender and diet of the snake. This means that only venom harvested locally can produce efficient antivenom. Sri Lankan scientists realised that the country needed to produce its own polyvalent antivenom to treat local snakebites.

Inescapably then, every country where snakebite is rampant must develop capacity to draw venom and process it for antivenom, rather than depend on imports from other countries, even if they are close neighbours like Sri Lanka and India.

Authorities in India, home of the Naga and a major exporter of antivenom, understand this fact and have embarked on a plan to develop antivenoms specific to each of its numerous provinces. India hopes that the new Sri Lankan antivenom will be effective against its own cases of hump-nosed pit viper envenomation as the species is abundant in its Western Ghats region, which has similar weather and flora to Sri Lanka.

However, Sri Lanka is yet to begin commercial manufacture of its polyvalent antivenom. When it does, there is every chance that it will fail against the Indian variety of the hump-nosed pit viper. India has, so far, not developed its own antivenom for this species, due to a lack of investment and research on the hump-nosed pit viper, confined to a relatively small area of the Indian peninsula. 

South Asia’s dilemmas are reflected in the situation of other regions like Sub-Saharan Africa, Latin America and the Pacific, where snakebite solutions rely on local initiatives supported by global collaboration and technology transfer.

To tackle the problem, the world needs a global matrix of antivenom research. Laboratories in countries like India, which has been manufacturing antivenom for more than half a century, can be upgraded to generate antivenom suitable for the less resourceful parts of the world. The pharmaceutical and biotech capabilities and the scientific manpower available in countries like India and Sri Lanka can be harnessed into this global matrix. 

Antivenom manufacturers and biopharmaceutical capabilities that exist in many other middle-rung developing countries — like Brazil, Egypt, Mexico, South Africa, Thailand and Vietnam — can form the hub of the matrix. Countries that have a high incidence of snakebite cases, but with poor resources, can also play an active role by hunting and breeding poisonous snakes and extracting venom hygienically to be forwarded to research and manufacturing facilities elsewhere.

With the WHO swinging in last year to reclassify snakebites as a neglected tropical disease, there is an opportunity to build international collaboration with all the necessary components for the matrix. But what are these components? They start with the maintenance in all vulnerable countries of snake farms for medically important species for the production, control and regulation of snake antivenom.

Secondly, with strict quality control protocols in place, the menace of fake, ineffective or inappropriate antivenoms that are to be found in the markets would disappear. Advances in genetic biotechnology already make it possible for laboratories to trace the provenance of all antivenom, but regulatory authority is missing.

Finally, every country, big or small, must maintain laboratories that can test the efficiency of antivenom and independently monitor results regardless of what manufacturers claim on product literature or at the point of national registration.

The result of this matrix could be better access to quality antivenom. But many countries need more than that, including specialised training for medical personnel and basic infrastructure. More efforts must also be made to build awareness among communities on first-aid for snakebite and what to expect by way of advanced treatment once at the clinic or hospital.  

There are signs of success. Pakistan, once a major importer of Indian polyvalent antivenom, now manufactures its own, through the initiatives of the Islamabad-based National Institute of Health, and provides free treatment for snakebite victims who reach a government medical facility in time. At district-level, these facilities are equipped with ventilators and dialysis machines to deal with emergencies arising from venom or treatment with antivenom.

India’s department of biotechnology has begun the work of standardising antivenom produced by local manufacturers, which will have a bearing on importers like Kenya and other African countries. The department also supports the production of large volumes of an affordable single-dose pan-Asian antivenom using recombinant technology. In addition, it has released a diagnostic kit to quickly and reliably identify snake species when a bite victim is unable to do so.These initiatives are important because India not only accounts for half of all snakebite mortality worldwide, but also has public-sector laboratories capable of leading international research, as well as a massive pharmaceutical manufacturing capability. In short, the country has both the disease and the cure.

In developing viable partnerships, a leaf can be taken out of the success of the Global Alliance for Vaccines and Immunisations that has dramatically increased access to vaccines and medicines to the those in greatest need. Given that WHO’s list of essential medicines includes antivenoms, their production should be profitable enough for local manufacturers, especially when given government incentives and support.

Among the many legendary manifestations of the snake’s real-life impact is the rod of Asclepius. This ancient Greek symbol — a staff embraced by a snake — remains to this day the badge of apothecaries around the world. Historians believe that the snake represents the god Asclepius’s success at healing snakebites, as prevalent a problem in ancient history as they are today.

Efforts to find treatments for snakebites are as old as humanity itself. But with modern medicine, a new era is dawning. As countries pool resources, swap knowledge and raise awareness, maiming and death caused by the venomous serpent may soon itself become the stuff of legend.

This piece was produced by SciDev.Net’s Asia & Pacific desk.