The end of river blindness

Twenty years ago Benin was among the countries in West Africa most affected by endemic river blindness. Today the disease, which causes blindness and chronic skin irritation and is blamed for stunting economic growth of the populations it affects, has been almost completely eradicated.

“We have massively decreased the incidence of the epidemic,” Laurent Assogba, a director at the Benin ministry of health said.

Health workers are holding the country up as an example of what can be achieved with sustained funding and political will.

The World Health Organization (WHO) describes Benin, and other West African countries where river blindness has been eradicated, as an “ongoing success story” and an example of the “value of synergy” that is necessary for good disease control programmes.

When, in 1994, international agencies and the government first conducted a survey in Benin for river blindness, also known by the medical term onchocerciasis, between 25 percent and 98 percent of people were found to have it.

Some 51 communities of the 77 in the country were living in a 81,000 sq km area deemed “endemic” by the survey.

Today, the highest rate of infection anywhere in the country is 3 percent and in most areas it is 1 percent or less, according to the ministry of health.

Onchocerciasis is an insect-borne disease caused by the parasite onchocerca volvulus which is transmitted by various species of blackflies of the Simulium genus. It is often called river blindness because blackflies abound in fertile riverside areas.

But onchocerciasis is still a major cause of blindness in many other African countries with the result that communities become unproductive.

The disease can be controlled either by eradicating the blackfly or with regular doses of the drug ivermectine which also relieves severe skin itching, though it cannot reverse blindness.

Albert Sinatoko, coordinator of the national programme against transmissible diseases in Benin, said it was only after the introduction of the drug ivermectine in 1988 that the number of people infected started going down.

“We found that the oral dose of ivermectine taken one or two times a year reduced the amount of the infection in people’s blood by 99 percent,” he said.

Since 1996, community-based ivermectine treatment programmes have been conducted by the African Programme for Onchocerciasis Control (APOC) in many other African countries, mainly in West and Central Africa.

Drugs are distributed by members of the communities, trained and supported by international agencies, governments and donors.

The World Bank estimates that eradicating river blindness has already prevented 600,000 cases of blindness plus it has made 25 million hectares of land habitable where once the disease was endemic.

But according to the non-governmental organisation (NGO) SightSavers International, 300,000 people in the world will remain blind because of the disease and 18 million are still affected. Of those, 99 percent live in Africa.

A further 125 million are “at risk” of infection, the NGO said.

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