A public health problem nearing a solution A child guides their
blind parent / Credit : Sightsavers In many regions of tropical
Africa, it is children who have to guide the steps of the blind.
Some years ago, people used to find "cursed villages" near
rivers where almost all adults had become blind. Children were
forced to leave school, if schools even existed at all, to take
care of their parents... while they wiated to become blind
themselves. There was no curse on any of these villages. They
were simply situated near running water that the villagers used
to drink and irrigate their fields... but also allowed small
black flies, known as simulium flies, to develop. These flies
are the carriers of the parasite that causes onchocerciasis,
also known as "River Blindness". _ Black fly breeding site (WHO
photo) When a black simulium fly bites a human, the worm larvae
are transmitted under the skin of the host where they develop
into adults and form nodules under the skin. When they breed,
millions of larvae are p