A dreaded tropical disease marked by grossly swollen limbs may someday become a historical footnote. Pharmaceutical giant SmithKline Beecham and the World Health Organization (WHO) today announced a joint $1 billion project to eliminate the often-debilitating scourge--called lymphatic filariasis, or elephantiasis--from people by the year 2020.
Some 120 million people in 73 countries are infected with lymphatic filariasis, caused mainly by the parasitic worms Wuchereria bancrofti and Brugia malayi, according to WHO. The adult worms lodge themselves in the lymph vessels, damaging them and the kidneys and often producing elephantiasis, a swelling of arms, legs, and genitalia. The worms produce larvae in the bloodstream that are ingested by mosquitoes, which then transmit the larvae to other people.
Experts say the most promising strategy for wiping out the disease is to destroy the larvae. Toward that end, SmithKline Beecham is donating to WHO 5 billion doses of the drug albendazole, worth about $500 million. Participating countries will pay for staff to distribute albendazole as well as locally produced or generic versions of two other drugs--diethlycarbamazine and ivermectin--effective against the parasites.
Eradicating the disease is "a fantastically exciting prospect," says Juliet Fuhrman, a filariasis expert at Tufts University in Medford, Massachusetts. But the task won't be easy. It takes up to 5 years of treatments to purge worms from an individual's lymphatic system--a daunting challenge considering that many prospective patients live far from clinics. "The question is," says Fuhrman, "Can you treat people long enough to abolish further transmission?" The answer may come at least 20 years from now, after countries start disbursing the drugs later this year.