School children in communities such as Daboase and Kyekyekrobo in the Western Region are forced to wear protective clothing to avoid being stung by the flies.
Onchocerciasis or River blindess is an eye and skin disease caused by a worm transmitted to humans through the bite of a blackfly .
These flies breed in fast-flowing streams and rivers, increasing the risk of blindness to individuals living nearby.
Within the human body, the adult female worm (macrofilaria) produces thousands of baby or larval worms (microfilariae) which migrate in the skin and the eye and which results in itchy eyes and eventually an irreversible blindness.
Assemblyman for Kyekyekrobo Solomon Owusu told Joy News the invasion is a perennial problem which the Health Ministry has been trying to contain.
“The ministry of Health has been giving us medications as and when the flies come around…It is something that happens every year”, he said.