What is River Blindness?

River blindness, also known as onchocerciasis, is a parasitic disease. The word river is associated with onchocerciasis for the simple reason that the black flies which cause this diseases multiply quickly in river areas. This is the place where humidity is high and the speed of the water is fast.

Signs and Symptoms

Visibility of signs and symptoms occurs very late. It may from take three months to more than one year to show the symptoms. The changes in the skin due to onchocerciasis are described as lizard skin, elephant skin or leopard skin.

The changes are observed to be characteristic of the geographical area where the infection may have taken place. For example, a thickened earlobe is characteristic to Central America, formation of nodules below the waist is seen in Africa. The same nodule formation is seen above the waist in South America.

Development of nodules takes place according to the feeding pattern of the black flies. These nodules carry adult live worms which may be multiplying within, producing younger worms. Hanging groin is common in Africa. Tissues containing infected nodes hang like sacs from the groin in this condition.

Inflammation of the lymph nodes occurs. Patches of depigmented skin may appear, resembling that of the leopard. The skin may become wrinkles and darkened. Skin rashes, accompanied by itching are common. The skin feels hot and appears swollen.

Worst is the condition when the nodules containing live worms develop on the scalp.

Treatment

There is no sure cure for river blindness but drugs like ivermectin are effective against microfilariae which are contained in the nodules. But repeated, well monitored doses must be given to show a significant effect.

The microfilariae occurring often cause blindness. In these cases, the drugs may be able to treat the infection but can not reverse the blindness. Also, the skin damage and the hanging groin can not be replaced with the drugs. Cultures of Onchocerca volvulus show that they can used to treat river blindness.

River blindness is said to be originated in Africa. But the infection has spread to other parts of the world including Columbia, Yemen, Saudi Arabia, Venezuela and Mexico.