Onchocerciasis

Onchocerciasis: Onchocerca volvulus in skin/eye; ocular damage can cause blindness → river blindness.

Common Symptoms

Pruritus; nodule; corneal opacity; itching

Causes and Pathogenesis

Adult white filiform; female 33.5-50 × 0.27-0.40 mm; male 19-42 × 0.13-0.21 mm. Microfilariae unsheathed, two sizes; 285-368 × 6-9 µm / 150-287 × 5-7 µm; not in peripheral blood, in skin lymphatics near adult; survive ~30 months. Simulium blackfly vector; L3 develops 6-7 d in thorax; infective in labium; human infective; adult maturation ~1 year; lifespan up to 18 years (usually 8-10). Pathogenesis: adult nodules in skin lymphatics; chronic inflammation → elastic fiber loss/atrophy/fibrosis; granuloma with eosinophils/giant cells/PL; microfilariae cause punctate keratitis/corneal opacity/iridocyclitis/chorioretinitis/optic atrophy → blindness.

Treatment

Drug therapy, supportive therapy

Preventive Measures

Avoid endemic areas; blackfly control.

Department to Visit

It is recommended to visit the Infectious Diseases department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.