Five million people worldwide, mostly in rural Asia and Africa, get bitten by snakes each year. Hundreds of thousands die or suffer permanent disability. A shortage of antivenin treatment in poor countries endangers countless farmers, young adults and children.

Larry Bulanadi is known in the Philippines as the Cobra King, because of his skill in hunting the feared spitting cobra - a highly venomous snake that spits toxin at its prey.

Farmers have asked him to rid their farms of cobras. 

On one day recently, Bulanadi was called by a farmer who found two snakes in his field. If he gets bitten by a cobra, he could die quickly. Hospitals are far away and often they do not even have antivenin.

"There is a good chance to find snakes here because the field has been cleared of places they could hide," Bulanadi said. "Farm owners ask us to clear the field of snakes because it is a risk to their lives."

The World Health Organization (WHO) says about five million people around the world are bitten by snakes each year. As many as 200,000 die, and about 400,000 lose limbs. Most victims are in developing countries in Africa and Asia.

The WHO says victims in developing countries, many of them children, die because they are far from medical help and because there is a global scarcity of antivenin.

Dr. Visith Sitprija runs the WHO Collaborating Center for Venomous Snake Toxicology and Research in Bangkok. He says the high cost of producing antivenin means poorer countries such as Cambodia and Burma cannot get adequate supplies.

"It's our commitment and in the terms of reference with WHO that we have to provide antivenin. They order from us from time to time," Dr. Visith says, "but still we are not serving entirely the whole country, their country."

Unlike other medicines that can be mass produced, Dr. Visith says antivenin is often tailor-made for snakes from specific locations. "Although they may share the common toxin component, the biological effect varies, you know depending on the environment, genetics and the food they eat," Dr. Visith said.

That means antivenin for a spitting cobra in the Philippines may not work on someone bitten by a similar snake in West Africa.

In one snake farm in Bangkok, children are introduced to a variety of snakes. They learn that most snakes bite people only by accident, and they learn ways to avoid bites - such as wearing rubber boots.

For now, experts say the best ways to reduce the death and injury toll from snake bites are prevention and education.