This is the VOA Special English DEVELOPMENT REPORT.
Doctors in Cameroon have found that giving the drug that fights river blindness more often can reduce the organisms that cause the disease.
Eighteen-million people suffer from river blindness. Almost all of them are in southern Africa. A smaller number of people in Latin America also have the disease. The medical name for the disease is onchocerciasis (on-ko-sir-KYE-uh-sis).
It is caused by a parasitic worm organism that lives for as many as fourteen years in humans. Each adult female worm grows to be one-half meter in length.
The females produce millions of tiny baby worms that move through the body. The movement of these baby worms can cause skin and eye problems, including blindness. Black fly insects pass the parasite to humans.
Doctors usually give patients the drug ivermectin (eye-ver-MEK-tin) one or two times a year to kill the baby worms. However, this treatment does not kill the adult female worms, which keep reproducing.
Because of this, doctors have to keep treating patients until the adult worms die of old age. This can take a long time. And it is difficult to reach patients in some villages in parts of Africa and Latin America.
However, a recent study in Cameroon has found that more treatments of ivermectin can reduce the number of adult worms in patients. Brian Duke of the River Blindness Foundation in Lancaster, England led the research.
The scientists studied about seven-hundred patients with the disease for three years. Some of the patients were given ivermectin every three months. Some of them got the medicine once a year.
The results showed that about one-third more adult worms died in the patients who were treated with the drug every three months. Details of the study were reported in The Lancet.
Scientists say the results of the study are important. However, they believe more research is needed to test if ivermectin reduces the spread of river blindness. If it does, health experts believe the disease could be ended in Latin America. That area has only one percent of the world's river blindness cases. Doctors believe they may be able to reduce the number of cases in Africa.
Health officials say that giving ivermectin more often would not cost more money. Currently, the American drug company Merck provides the medicine at no cost.
This VOA Special English DEVELOPMENT REPORT was written by Jill Moss.