Washington
23 January 2008
Three antiparasitic drugs may soon be dispensed simultaneously to people living in areas in Africa that are endemic for parasitic worms. The results of a large study from Zanzibar show administering three drugs at the same time causes minimal side effects. Experts say the regimen, if adopted, would result in significant cost savings. VOA's Jessica Berman reports.
Experts say many people in Zanzibar and other parasite-endemic regions are usually infected with more than one type of worm.
Antiparasitic drugs are given each year to manage the worm infections. The drugs are not usually dispensed at the same time for all of the diseases. Public health officials say time and resources could be saved if all three drugs could be doled out simultaneously.
The study in Zanzibar, part of Tanzania, involved a three-drug regimen of Ivermectin, albendazole and praziquantel. The drugs are active against worms that cause elephantiasis and schistosomiasis and soil-worms or helminths.
An estimated 200 million people worldwide are infected with the worm responsible for schistosomiasis, which is caused by bathing in river water contaminated with human waste.
The parasites burrow into the skin, eventually finding their way to vital organs including the liver, lungs and intestines, where they reproduce, wreaking havoc on their human host.
More than one billion people in 80 countries are at risk of contracting lymphatic filariasis, known as Elephantiasis, which is transmitted by mosquitos infected with parasitic filarial worms. The worms lodge in the lymphatic system, causing accumulations of lymph fluid that lead to massive swellings of limbs, usually the feet.
The first phase of the study involved more than 5,000 children. After finding no severe side effects to the triple therapy, investigators from Zanzibar and Tanzania - as well as from the School of Tropical Medicine in Liverpool, England - expanded the trial to treat Zanzibar's entire eligible population of 700,000 people.
Again, investigators found the side effects were minimal when the drugs were given together.
David Molyneux is with the Lymphatic Filariasis Center at the School of Tropical Medicine in Liverpool. He says that drug companies are donating two of the antiworm drugs, Ivermectin and albendazole.
Molyneux adds that a dose of the third drug, praziquantel, to treat schistosomiasis, costs 20 cents.
"Basically what we are saying is that for 50 cents - which would be 20 for the praziquantel, 30 cents for the delivery and the social mobilization - you could really make pretty big cost savings in delivery and treat the targeted populations across a much wider area of Africa," he said.
Molyneux is co-author of the study on the triple drug regimen, which is published in an online journal of the Public Library of Science.
Molyneux says further studies will be done to confirm the safety of the three-drug regimen, which could then be submitted to the World Health Organization for approval.