The magical substance that prevents snakes and spiders from killing you

There once was a time when the popular way to relieve snake and spider bites was cutting the wound and sucking out the venom. That didn't work. Now people use substances called antivenoms. Find out how antivenoms save people from the poison of spider bite, snake bite, or worse.

In the Beginning

In the old days, fueled by a proliferation of westerns and a can-do spirit, people believed that there were several ways of treating a snake bite. The first was to make an incision in the bite and try to suck out the venom. That removed very little venom from the bite, and what was removed ended up in the rescuer's face. It didn't help things. Other folk wisdom held that a tourniquet had to be applied around the affected limb. That rarely helped either, and often just ended up costing the person the limb through the venom or the restriction of blood flow. Later, people were told to put ice on the area. This also did more harm than good.

Now, the general consensus among medical professionals is, "The less done the better." People who have been bitten by snakes are told to wash the bite, but not flush it, with soap and water. They are to splint the area, so it doesn't move, and keep it lower than the heart. If medical help is not within 30 minutes, they can apply a loose bandage to mildly slow blood flow, and apply suction if they have a snake bite kit. But the best thing to do is to get to a hospital, where they have the proper tools to deal with venom.

The First Breakthrough

The first antivenom was made in 1895, at the then-Indochine branch of the Pasteur Institute. A scientists named Albert Calmette developed a basic antivenom to the bite of the Indian Cobra. Calmette took the cobra itself and extracted venom. The process, called milking, involves hooking the snake (or spider's) fangs over the edge of a jar and pressing on the animal's head or body to cause it to secrete the poison as a defense mechanism. The venom is collected in a jar. The scientist then takes the venom and injects a nonlethal dose into a mammal. The first antivenoms were developed in horses, but they've since branched out to sheep. Over time, the mammal is given larger doses of the venom, until it can walk off a higher-than-lethal dose.

Once the mammal has acquired in immunity to the venom, the researchers extract vials of its blood. The blood is put in a centrifuge, which separates out the white blood cells from the rest of the blood. These blood cells carry in them antibodies powerful enough to fight off a lethal dose of venom. They are sent to hospitals, and when a human victim comes in, they are given to the patient. Ideally, the antivenom will be injected less than five hours after the initial bite.

Widening the Field

As might be expected, there have been some updates in antivenom production over the last hundred years. Many more antivenoms have been developed. Some are monovalent, used for only one type of venom, while others are polyvalent. Some polyvalent antivenoms are just mixes of different antivenoms put together. They're usually combined to fight the venom of all the snakes or spiders in a particular geographic region. Bite victims often can't identify the creature that bit them, so once a mild reaction has been confirmed, the antivenom is injected to give the victim the best chance. Other antivenoms are polyvalent simply because they happen to work for two different types of venom. The Australian redback spider antivenom also works, to a certain degree, on black widow bites.

The animals used to build the antibodies have also changed over the years. Horses were the earliest animals used to make antivenom, but a number of people are allergic to them. They either had bad reactions to the antivenom or had to chance going without. Researchers moved to sheep, which aggravates fewer allergies. Recent antivenoms have been made by injecting minute quantities of venom into young chickens. As the chickens grow, and the doses of venom increase, they pass their antibodies to their offspring through proteins in their egg yolks. These can be harvested cheaply and may make antivenom more available to poor and rural areas.

There When We Need It?

But it's not an entirely rosey future for antivenom. It's expensive to manufacture, and demand, especially in developed countries, is low. Even in countries that have a lot of snake bites, hospitals have a hard time estimating the right amount of antivenom to stock. As manufacturers stop making the antivenom, the price goes up and demand gets even lower. And that's if there's any antivenom to be found at all. Wyeth was the only manufacturer of coral snake antivenom, and it recently stopped making the product at all.

Those who get bitten by a snake need not despair. Most injections of venom aren't fatal. Often, bites don't even deliver venom. Experts estimate that anywhere up to forty percent of venomous snake bites are 'dry bites'. The snake either has not made any venom since a previous bite or has miscalculated and sprayed its venom on the ground before or after the bite. So, if you are reading this while clutching your ankle; remain calm.

And go find some soap and water.

Top Image: Kamalnv

Via eHow, Survial Topics, Mayo Clinic, and, Tampa Poison Control Center, National Geographic.