Onchocersiasis (river blindness)
Onchocerciasis is an insect-borne disease caused by a
parasite Onchocerca volvulus and transmitted by blackflies of the species
Simulium damnosum. Onchocerciasis is often called "river blindness"
because the blackfly which transmits the disease abounds in fertile riverside
areas, that frequently remain uninhabited for fear of infection. O. volvulus is
almost exclusively a parasite of man. Adult worms live in nodules in a human
body where the female worms produce high numbers of first-stage larvae known as
microfilariae. They migrate from the nodules to the sub-epidermal layer of the
skin where they can be ingested by blackflies. They further develop in the body
of the insect from which more people can be infected. Eye lesions in humans are
caused by microfilariae. They can be found in all internal tissues of the eye -
except the lens - where they cause eye inflammation, bleeding, and other
complications that ultimately lead to blindness.
In the early 1970s, seven West African countries beset
by drought and food shortages: Benin, Togo, Ghana, Burkina Faso, Mali, Niger
and the Cote d'lvoire, joined together to appeal for help. They approached a
number of organisations, one of the more important being the 
World Bank, whose president was
Robert McNamara. Flying over six West African countries, McNamara remarked to
one of his companions that there seemed to be large areas of presumably fertile
land beside the rivers which remained uncultivated. Couldn't this produce more
food? he asked. He was told that the riverine land had been abandoned: the
people had fled the scourge of river blindness. "The worst thing
about it - this sounds brutal is that it doesn't kill", said McNamara.
"Some commit suicide
as the bites are so irritating, and some go blind. I saw in these very
primitive African villages adults, male and female, being led around at the end
of a stick, because they weren't dead, they had to be fed, but they couldn't
contribute to life it was a horrible
situation."
At that time river blindness or onchocerciasis, to
give it its medical name affected over one million people in 
Entire regions had been abandoned,
with over 25 million hectares of farmland lying idle.
The Onchocerciasis Control Programme (OCP) was set up in 1974 with the
World Health Organisation as the executive authority. It spanned eleven affected
countries. The programme adopted a two-prong approach: while the search
continued for a cure for the disease, an operation of military precision was
mounted against the infected blackfly.
Link
Information on Onchocersiasis on the WHO website.
Stamp catalogue
Niger
last revised: