Onchocerciasis (River blindness)

Onchocerciasis – or “river blindness” – is a parasitic disease transmitted by repeated bites of infected blackflies.

Causes

Filarial nematode Onchocerca volvulus (the vector is a blackfly which breeds along fast-flowing rivers and streams)

Signs and symptoms

Pruritis is the most common early symptom – (can be mild to severe and intermittent to unremitting)
Lymphadenopathy in inguinal and femoral regions
Subcutaneous nodules over bony prominences
Visual changes can range from mild to frank blindness
Weight loss may occur
Dermatitis – acute or chronic popular dermatitis
Depigmentation in advanced cases

Investigations

Blood should be drawn at night and viewed under the microscope for the microfilaria

Pharmacological treatment

Ivermectin oral

Adults and children 5-17 years

150 microgram/kg as a single dose

Repeat

Intervals of 6-12months depending on symptoms until adult worms die out

Eye involvement

Prednisolone oral

1 mg/kg

Note: Start several days before treatment with Ivermectin

Surgical intervention