Last turn of the Guinea worm?

A "fiery serpent" that plagued the Israelites in the Old Testament and that's been found in Egyptian mummies continues to afflict tens of thousands of people today. The ancient parasitic sickness, known as Guinea worm disease, can still be cured only with an ancient remedy. But experts say the disease is on the verge of becoming ancient history, despite its age-old persistence and the lack of advances in medical treatments.

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Just half a century ago, tens of millions of people were affected by the painful and debilitating Guinea worm infection. Europeans dubbed the worm \o7Dracunculus medinensis\f7, or "Medina vein," for the holy Middle Eastern city once plagued by the parasitic disease. The Arabic word for the disease translates as Pharaoh's worm, harking back to the malady's first documentation several thousand years ago in Egypt.

But despite being observed for millennia, Guinea worm disease has proved tricky to defeat. The problem was long a misunderstanding: The worm itself, which grows up to 3 feet inside the human body and emerges through a festering blister on the leg, was mistaken for a rotting vein.

When medieval doctors finally concluded that it was, in fact, a worm, they thought people got it from walking barefoot, wading in dirty water or being exposed to sick neighbors.

In the 1870s, Russian explorer and scientist Aleksej Fedchenko determined (to much scientific dissent) that ingesting a water flea was to blame. Guinea worm larvae, Fedchenko said, resided within microscopic, one-eyed water organisms called \o7 Cyclops\f7. People who unwittingly drank \o7Cyclops\f7, he posited, became infected.

Fedchenko struggled to validate his theory by feeding flea-ridden water to cats and dogs. The pets resisted infection, however, and Fedchenko died in an Alpine climbing accident before ever proving his point.

Picking up where Fedchenko left off, English scientist Robert Thomas Leiper successfully infected a monkey by feeding it \o7Cyclops\f7-tainted bananas. But when Indian scientist Dyneshvar Atmaran Turkhud attempted to replicate the experiment a few years later, he failed.

Turkhud succeeded, however, in infecting humans. He persuaded five "volunteers" to drink water containing Guinea-worm-infected \o7Cyclops\f7. One year later he observed blisters in one of them, his lab assistant, proving the parasite's transmission cycle.