Science / Medicine : Spraying Saves Millions From River Blindness

The old man lifted his head to the cloudless sky, his eyes turned upward in the sightless stare of onchocerciasis--the crippling river-blindness disease that maims some 30 million people worldwide.

“It started here,” he said, stroking his chest with his huge, callused hands, “but then it went through my whole body and started eating my eyes.”

River blindness, known to some tribesmen in West Africa as “lion’s eyes” because of the glassy look its victims acquire, is one of the world’s major parasitic diseases. By 1974, the fly-borne disease had reached major proportions along the banks of the mighty Volta River, afflicting 1 million people out of a population of 10 million.

But a costly international program to fight the scourge that plagued the Volta River Basin is scoring spectacular successes, having virtually broken the transmission chain of the disease in seven West African countries.

“This is a great success story,” said Ebrahim Samba, director of the World Health Organization’s Onchocerciasis Control Program in Ouagadougou.

“One cannot stress its importance enough, because when you are blind in Africa, you are finished,” he said.

In much of the region, blindness was long considered an almost certain destiny. Many of the blind old men, clutching the end of a stick to be led by small children, attribute their plight to the dreaded evil spirits that West Africans tend to blame for nearly every kind of misfortune.

Affliction of Jungle

Some 45 miles from the capital, in the small village of Weyem, Boukari Sigiyan, 75, pointed to his lifeless eyes and said it was “the affliction of the jungle.”

He did not know that the disease was transmitted by the black fly that breeds along the river and whose repeated itchy bites caused him to move away from the banks of the Volta.

But he did know that the blindness, and before that the excruciating pain, were somehow related to the river.

“When you go to the river to fetch water at night, the wind carries bad spirits from old trees that spoil your eyes,” he said.

The Volta River was once a major breeding ground of the black fly--known to scientists as Simulium damnosum because of the damnable itch its bite provokes.

When the female black fly bites an infected person, it sucks in with the blood a few tiny worms known as microfiliarae, which develop into infectious larvae within a week.

The larvae are transferred to another human by the fly’s subsequent bite, and they develop into mature worms under the skin, producing nodules that can reach the size of golf balls.

The female worm produces millions of embryos, which invade the whole body, causing rashes, depigmentation, painful swellings and, in heavily infected people, blindness.

For villagers who spent their lives near the rivers, infection was until recently a virtual certainty. In some areas, as many as 1,500 bites a day--more than 100 an hour--were recorded before the control program started in 1975.

The banks of the White Volta--renamed Nakanba in Burkina Faso--used to be the epicenter of the disease. Today, none of the children playing in the river at Kongri, near Weyem, can remember being bitten.

“We sprayed pesticide here from 1976 to 1977 and have had no black flies since. We have broken the cycle of transmission,” said Emile Senghor, information officer for the control program.

“The children here are now safe and will never suffer from ‘oncho,’ ” he said.

“People abandoned their land near the river to settle in the arid regions on the edge of the Sahara. Now that they know it is safe here, they have returned to till and graze their cattle on the well-irrigated soil and to fish in the river,” he said.

Heard the Planes

Boukari Ouedraougou, 45, used to fish in the Nakanba “many years ago. But I caught the illness of the jungle, the one that comes from the flies and eats the eyes. I was very sick, it was very painful, I thought I would die,” he said.

Pointing to the sky he could not see, he said he heard the planes of the oncho control program flying overhead “some time ago.”

“There was a lot of talk, so I know they were treating the river. Now, there are no flies and no bites. It is because of the treatment they have done. It was a very good thing,” he said, smiling.

Sponsored by several United Nations agencies and the World Bank, the control program initially covered an area of 299,900 square miles in the West African states of Benin, Burkina Faso, Ghana, Ivory Coast, Mali, Niger and Togo.

Recent reports showed transmission was halted among 16 million people and was “under control” in 90% of the original area, opening up new land for development. The program, which is implemented by World Health, was recently extended to cover an additional 501,800 square miles in Guinea, Guinea-Bissau, Senegal and Sierra Leone.

Financed by several international donors, including the United States, Saudi Arabia, Japan and European nations, the program cost $160 million in its first 10 years, and expenses forecast for 1986 to 1991 are for $135 million.

“We are spending $25 million a year and serving a population of 26 million--that’s about $1 per person per year, which is really quite good,” Samba said.