W. Africa Gains Hope of Ending River Blindness

From the time he was a toddler, Moriba Katmara fought off the black flies. To be bitten 200 times a day while working in the fields was not unusual, and the tiny drop of blood left by each bite would have turned into a thick stream by nightfall.

Katmara and half the men in his village are blind now because of those flies. Small children lead him from place to place. His life’s work consists of making rope and shelling peanuts. He has given up hope he’ll ever marry.

Katmara is only 28 years old.

“My future depends on my young brothers,” he said recently, sitting on a grass mat in this small African village. “If they do not become blind, they can help me through life.”

Untreatable Disease

Thousands of rural villages in West Africa have been plagued since recorded history by those small flies and the untreatable parasitic disease they transmit--onchocerciasis, better known as river blindness because it afflicts villages located near streams where the black flies breed.

The villagers call it mara --enslavement.

Today, however, there is hope for Sakarabunda and other of Africa’s so-called “blind villages,” where more than 1 million people are infected with the disease and at least 100,000 are blind.

The people here recently began taking a new drug, developed by an American firm, that interrupts the reproductive cycle of the parasite. And this year Sakarabunda will become part of the World Health Organization’s pesticide-spraying program, which already has halted the transmission of river blindness in an area of Africa about one-fourth the size of the United States.

“We know we are ill, and there is nothing we can do about it,” said Fassoro Kaita, the 60-year-old chief of Sakarabunda, who has been blind for 10 years. “But we can still help the young people and keep our village alive.”

In the mildest cases, mara causes violent itching that can persist for a lifetime. In the worst cases, which primarily affect adult men because they farm near the rivers, it causes eye disorders and, eventually, permanent blindness.

On a continent where large, expensive battles against diseases such as malaria and AIDS have so often failed, the effort to control river blindness is an exception. In the past 10 years, 4 million children have been born into areas now free of the parasite.

The WHO program, supported by 21 countries including the United States, was launched in seven West African countries in 1974. It was designed to eradicate the black fly for 20 years--long enough, scientists believe, to snuff out the disease.

Cycle Starts With Female Fly

The cycle of river blindness begins with the female fly, which is smaller than an ordinary house fly. When it bites a person, the fly deposits the larvae of a parasitic worm in the human skin. The worm grows to adulthood and annually produces as many as 1 million microfilaria, smaller worms that move throughout the body in the skin, causing itching, depigmentation and lesions on the eyes.

Some of those microscopic worms are eventually ingested by biting flies, transformed into the larvae of the parasite and again deposited when the fly bites another human, thus restarting the cycle.

WHO intends to break that cycle by keeping the flies away until all the adult parasites in the skin, which have a life span of about 12 years, have died. Because the black fly breeds in fast-flowing water, WHO has 11 helicopters and three airplanes that search and, when necessary, spray 11,000 miles of rivers every week to kill the fly larvae.

Now the WHO program has added new territory west of Mali’s capital, Bamako, expanding its main area of operations by nearly 25%. The WHO staff in Bamako, about 35 miles east of Sakarabunda, will swell to 400 from 155 as the battle against black flies begins in these previously unprotected areas.

Drug Must Be Taken Yearly

The inhabitants of several villages in the area, including Sakarabunda, already have begun taking ivermectin, a new drug that kills the small worms responsible for causing blindness. Because it does not kill the adult parasites, however, ivermectin tablets must be taken every year until the adult worms die.

Merck & Co., a Rahway, N.J.-based company, sells the drug to combat parasites in livestock. But it has promised to donate all of the ivermectin needed to wipe out river blindness in humans.

Many scientists believe that the drug and the pesticide-spraying program will both be necessary to control the disease.

River blindness has been a social as well as medical problem for this region. Viewed as a curse from the gods, it touched off massive dislocation over the years.

Some People Fled Homes

Sensing the rivers were to blame, villages abandoned fertile fields near them and tried to farm the rockier hillsides. Some people simply fled their homes and moved to the large cities to escape the scourge.

Sakarabunda itself has been moved twice in the past century--once up to the top of a hill and then back down again. A collection of grass huts arranged in tidy circles, it sits today amid a productive part of southern Mali. The people grow millet and rice in fields alongside the narrow Koba River less than a mile away.

Mara has been a fact of life here as long as memory.

“Before we discovered the cause, we thought it was the water,” said Chief Kaita. “If you drank the water in this village, we thought, you became blind after 50 years or so. Of course, there were many insects biting us--tsetse flies, black flies--but we didn’t relate them to blindness.”

Remains Ostracized

To this day, Sakarabunda remains ostracized by its neighbors.

A young man here recently was about to marry a woman from a nearby village until her parents discovered that Sakarabunda had many cases of mara . Young women born in Sakarabunda find they also have trouble marrying men who live farther from the river.

“We are isolated. Other villages will not work with us. They think if their sons or daughters come here, they will also get the disease,” Kaita said. “But our biggest problem is the young men who become blind before marriage. No one will ever marry them.”

Once, Sakarabunda had 800 residents. But as the blindness spread, the size of the village dwindled. Now about 100 people live in Sakarabunda. Nearly all have some symptoms of the disease and 15, most of them men, are blind.

Ignominious Existence

Blindness usually occurs after 10 or 20 years of being bitten daily by hundreds of flies. The blind men can no longer work in the fields, and they usually end up helping the women with the garden or, as Moriba Katmara does, weaving rope. It is an ignominious existence in a society where males are seen as the providers.

“If you are blind, you are like a dead person,” said Katmara, who has been blind six years. “You can walk. You can speak. But you are dead.

“When I began having trouble seeing six years ago, I thought different things. I thought I was ill because I was mean to other people. Other times, I thought I was blind because I could not afford witch doctors like rich people. But now I think it is God.”

Katmara and others who have taken the drug ivermectin say they feel their health has improved, although the eye damage generally is irreversible. Medical tests indicate the level of microfilaria dropped precipitously after the medicine was administered last summer but is now increasing again. The villagers will receive a second dose of the medicine in a few months.

Patriarch Has Difficult Job

Kaita, a gaunt, stooped man with a white beard, is the gentle patriarch of all he cannot see. He carefully plans the planting of the fields, making sure the village has enough to eat. But he says his job is difficult because children must lead him around by his cane.

“I cannot get anything for myself. Always people have to say to me, ‘Take this’ and ‘Take this.’ ” he said. “But we are not animals. We have children and relatives to take care of us.”

The medication and WHO’s plans to fight the black flies here make the chief hopeful for his village.

“If the treatments continue and the disease decreases, more people will want to come here and settle near us,” he said. “We are, after all, near the river. And we can farm all seasons.”

But when it comes to mara , the people of Sakarabunda are reluctant optimists.

“I am still worried,” said the chief’s 12-year-old son, Fabien. “Look at my father. I don’t know what will happen to me.”