“So with browns (snakes), blacks, copper heads, everything bar basically the death adder and Taiwan, they can handle that.” (ABC Rural: Brown Herbert) “We are the only ones in Australia that produce a bivalent, like a tiger-brown snake combined,” Mr Curtis said.
(ABC Rural: Brown Herbert) Mr Curtis is carrying on the work of his father Dr Keith Curtis, a district vet who moved to the north coast to deal with the tuberculosis outbreak in cattle and first created a tick serum for dogs in 1957. “By the time you actually start producing antivenom it might take 18 months, so it's a very long, slow process in order to get to that point and that helps with how they will handle it,” he said.
Antivenom for people am also produced using horses, but requires another level of refinement to be safe for humans. The long hot days of summer bring an increased snakebite risk to all animals, including horses.
The major venomous snakes-the pit vipers-in the United States include several species of rattlesnakes, copperheads, and water moccasins. Risk of severe, fatal envenomation (poisoning from a venomous bite or sting) is highest with Diamondback rattlers, less with water moccasins, and lowest with copperheads.
Severe bites from more dangerous snake species or larger doses of venom can cause marked pain and swelling, coagulopathy (blood clotting defect) and hemorrhage, cardiac arrhythmias, shock, collapse, and in some cases acute death. Horses bitten on the nose can develop swelling of the nasal passages resulting in respiratory distress.
Seek veterinary care immediately if a horse is bitten by a venomous snake. No first-aid treatments performed by owners in the field have been shown to be particularly helpful for venomous snakebite.
Additionally, suction devices designed specifically for venom removal have not been shown to be beneficial (in pig models of snakebite). Antivenin can be especially helpful in cases of severe envenomation and can decrease the amount of tissue damage and hasten recovery times.
Even after horses have recovered from a snakebite’s more immediate effects, subsequent complications such as chronic heart failure, kidney damage, and hemolytic anemia (a disease in which the body’s immune system attacks and kills its own red blood cells) can sometimes occur. Cardiac failure can occur weeks to months after the bite incident and appears to be more common in horses than other species.
Horses that have recovered from snakebites should be evaluated every few months for cardiac health, and owners should be watchful for signs that might suggest cardiac problems (e.g., shortness of breath, slow recovery after exercise, an increased effort to breathe, and general weakness). Contact your veterinarian or a veterinary toxicologist to obtain more information on snakebite and available vaccinations.
In a patchy ten-acre tractor grass in Coronado, a hilly exurb northeast of the Costa Rican capital of San José, a weedy horse paddock and corrugated metal stable stand adjacent to a building of pristine laboratories and climate-controlled habitats. Through one door is a necropolis of dead snakes preserved in glass jars arranged helter-skelter on a counter, reminiscent of a macabre Victorian cabinet of curiosities.
A variety of snakes preserved at the Institute Clodomiro Picador, in Costa Rica, a world leader in venom antidote production. (Myles Karl)The Institute Clodomiro Picador, or ICP, named after the father of Costa Rican herpetology, is one of the world’s leading manufacturers of snake antivenoms, and the only one in Central America.
In these regions’ poorer corners, local capacities for antivenom production are limited or nonexistent; the ICP has stepped in to help fill the gaps. Beyond meeting its own country’s needs, the institute has supplied or developed lifesaving antivenom for victims on four continents, each treatment customized to protect against species that still pose lethal threats, from the West African carpet viper to the Japan Taiwan.
Corrals’ colleague Danilo Charon referred to the specimen as a bichon Grande, using an untranslatable term that falls somewhere between critter and beast. The snake exhibited the characteristic scale pattern of diamond and triangles in light and dark brown, and the trilateral head that inspires the common name fer-de-lance, or lance head.
The handlers bent down and picked up the groggy terciopelo, Charon grabbing the head, Corrals lifting the tail and midsection. Above, in the serpentarium at the Institute Clodomiro Picador, Danilo Charon and Grain Corrals handle a live terciopelo, Bottrop Jasper, after sedating it with carbon dioxide gas.
He injected serial doses into small mammals in order to force their bodies to recognize and gradually develop antibodies as an immune response to the toxins in the venom. The institute produces about 100,000 vials of antivenom annually, for treating people in Central and South America and sub- Saharan Africa.
(The Institute Clodomiro Picador)Today, the ICP produces antivenom in much the same way, but with more advanced processes allowing for a purer product. “Our antivenom are basically solutions of horse antibodies specific against particular venom,” said José María Gutiérrez, a former director of the ICP and a professor emeritus at the University of Costa Rica, which oversees the institute.
The ICP’s roughly 110 horses live mostly on a farm in the nearby cloud forest and are brought to the stables to take part in antivenom production periodically. The antivenom are sent to hospitals, clinics and primary health posts, where they are diluted with saline and administered intravenously into snakebite victims.
Top, Clodomiro Picador, who was reared in Costa Rica and studied in France, was a zoologist, botanist and author of a 1931 book, left, about venomous snakes. Far left, Albert Chalmette, c. 1920, a French physician celebrated for his contribution to the tuberculosis vaccine, produced the first snakebite antidote in 1895, having studied venomous snakes while stationed in Saigon for the Pasteur Institute.
The ICP maintains a diverse collection of live snakes, mostly caught and donated by Costa Rican farmers and landowners, some bred in captivity. He unscrewed the top of a plastic container the size of a spice jar, revealing contents that looked like yellow ground mustard powder.
*Estimated amount of venom, in micrograms, to kill 50 percent of laboratory mice in a sample, if each mouse weighed 30 grams. The ICP’s success in maintaining and breeding snakes that otherwise fare poorly in captivity has allowed for the collection to include workable quantities of exceedingly rare venom.
For example, an innovative technique involving a diet of tilapia files sustains about 80 coral snakes in the serpentarium, a rare quantity. There’s no question that historical factors like accessible health care, the migration from rural to urban areas, and even a decrease in barefootedness contributed to the decline of snakebite deaths in Costa Rica.
(Susanne Settling / MSF)“We want to expand the knowledge and expertise generated in Costa Rica to contribute to solving this problem in other regions and countries,” said Gutiérrez, who is also a member of the board of directors of the Global Snakebite Initiative, a nonprofit that advocates for greater recognition and understanding of snakebite mortality worldwide, especially in impoverished regions. Even the United States, with its advanced medical science and robust pharmaceutical industry, has experienced occasional antivenom shortages.
Clark’s coral snake, native to rainforests in parts of Costa Rica, Panama and Colombia, is nocturnal and doesn’t often trouble people. For a decade the institute has been distributing a newly developed antivenom to Nigeria, capable of protecting against the venom of the West African carpet viper, the puff adder and the black-necked spitting cobra.
Bites from these deadly snakes had been treated in the past mostly with a polyvalence antivenom manufactured by Sanofi-Pasteur, but the French pharmaceutical giant, citing a lack of profit, ceased production in 2014, leaving a dangerous gap in the market. Named for the unusual scales protruding from its head, the eyelash viper is a venomous tree snake found from southern Mexico to Venezuela.
“For this reason the serpent, together with poison and the dagger, are signs of treachery and treason.” Gutiérrez is more measured, pointing out that snakes have been both gods and demons in mythologies around the world: “They’re fascinating, yet they can kill you.” If you're unlucky enough to have a poisonous snake sink its fangs into you, your best hope is an antivenom, which has been made in the same way since Victorian times.
© Benjamin Gilbert/ Welcome Scientists at the Liverpool School of Tropical Medicine's Center of Snakebite Research and Interventions, extract a snake's venom It involves milking snake venom by hand and injecting it into horses or other animals in small doses to evoke an immune response. © DESHAKALYAN Chowder/AFP/Getty ImagesExperts have long called for better ways to treat snake bites, which kill some 200 people a day.
“They've really moved the game on,” said Nick Carmack, head of the snakebite team at UK medical research charity Welcome. Hans Clever, the principal investigator at the Utrecht Institute for Developmental Biology and Stem Cell Research in Utrecht, never expected to be using his lab to make snake venom.
A decade ago, he invented the technique to make human organics -- miniature organs made from the stem cells of individual patients. They've allowed doctors to test the specific effects of drugs safely outside the body, something that has revolutionized and personalized areas such as cancer treatment.
© Luck Purina/CTK/AP The scientists have reproduced the venom gland of the Cape Coral snake, seen here in the Olympic Zoo, Czech Republic, on May 11, 2018. Clever said it was essentially a whim of three PhD students working in his lab who'd grown bored with reproducing mouse and human kidneys, livers and guts.
After sourcing some fertilized snake eggs from a dealer, the researchers found they were able to take a tiny chunk of snake tissue, containing stem cells, and nurture it in a dish with the same growth factor they used for human organics -- albeit at a lower temperature -- to create the venom glands. And they found that these snake organics -- tiny balls just one millimeter wide -- produced the same toxins as the snake venom.
© Avian van Infield/Princess Maxima Center The snake venom gland organics as seen under a microscope./ “Open them up and you have a lot of venom. We've compared it directly to the venom from the same species of snake, and we find the exact same components,” said Clever, who was an author of the paper that published in the journal Cell last week.
The current antivenom available to us, produced in horses not humans, trigger relatively high rates of adverse reactions, which can be mild, like rash and itch, or more serious, like anaphylaxis. Even if the people who need it can afford it -- most snakebite victims live in rural Asia and Africa -- the world has less than half of the antivenom stock it needs, according to Welcome.
One challenge to making synthetic antivenom is the sheer complexity of how a snake disables its prey. Researchers in India have sequenced the genome of the Indian Cobra, in an attempt to decode the venom.
In tandem, both breakthroughs will also make it easier to discover whether some potent molecules contained in snake venom are themselves worth prospecting as drugs -- allowing snakes to make their mark on human health differently to how nature intended -- by saving lives.