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Scientists Unlock Genetic Code of Debilitating Elephantiasis Parasite


An international team of scientists has broken the genetic code of a parasite that is responsible for one of the world's most debilitating illnesses, a condition called elephantiasis. As VOA's Jessica Berman reports, the breakthrough holds promise for the treatment of the disease that affects millions of people around the world.

According to the World Health Organization, more than 150 million people around the globe are infected with the parasite that causes elephantiasis.

Elodie Ghedin, a researcher at the University of Pittsburgh, led the DNA study leading to the genetic blueprint of the thread-like microscopic worm, known as Brugia Malayi.

Ghedin says Brugia causes debilitating symptoms in about 40 million people who are infected.

"The result are these huge limbs, usually the lower limbs, and it looks like elephant skin," said Elodie Ghedin. "And they are huge legs."

Ghedin say the parasite, which is carried by spiders and mosquitoes, threatens one billion people who live in countries where the disease is endemic.

Ghedin says elephantiasis is an disorder that targets the immune system. She says many people can be bitten by infected insects and never develop the condition while others develop a massive allergic reaction.

Experts say the only available treatment is not very effective and when it kills the parasite the worms release toxic molecules that can trigger a massive immune system reaction.

An infectious disease specialist at the U.S. National Institutes of Health in Maryland, Phillip Coyne, says elephantiasis can destroy lives.

"People that exhibit those manifestations are social outcasts," said Phillip Coyne. "They cannot marry. They cannot farm because they are debilitated because of the swelling of their limbs. So, it is estimated to be one of the leading causes of disability among the tropical infectious diseases."

Coyne says the Brugia parasite is itself infected with a bacteria it needs to survive.

In their work on the worm's genetic sequence, Ghedin and her colleagues from the United States, Australia, and Britain identified genes in the bacteria that are critical for the parasite's survival.

Ghedin says instead of making drugs directly attacking the parasite, one strategy might be to make compounds that target bacterial proteins the parasite depends on.

She says the work has given her an interesting list of genes that hopefully will shed light on the nature of Brugia. For example, Ghedin says she is interested in finding out how the microscopic worm invades and survives in the human immune system.

"And this is the type of thing I want to focus on right now is taking all those unknown genes that we know are unique to this parasite and try to test and see how they modulate the immune system - and which ones have the strongest effect on the immune system - this may help us find new therapies," she said.