Onchocerciasis: River Blindness, Causes and Prevention

Category: Science, Health and Diseases

UPSC Notes

Onchocerciasis, commonly called river blindness, is a parasitic disease caused by the filarial worm Onchocerca volvulus.

Transmission

  • Spread through repeated bites of infected blackflies belonging to the genus Simulium.

  • The blackflies commonly breed near fast-flowing rivers and streams.

  • The disease primarily affects rural communities in parts of sub-Saharan Africa, with smaller endemic areas elsewhere.

Symptoms

  • Severe itching.

  • Skin changes and subcutaneous nodules.

  • Eye inflammation and lesions.

  • Visual impairment, potentially progressing to permanent blindness.

Control and elimination

  • Community-wide administration of ivermectin in endemic areas.

  • Surveillance and monitoring of transmission.

  • Vector-control measures where appropriate.

  • Continued public-health interventions to interrupt transmission.

Key Pointers for UPSC

  • Causative organism: Onchocerca volvulus.

  • Vector: Blackfly (Simulium).

  • Disease type: Parasitic infection.

  • Drug used in control programmes: Ivermectin.

  • It is associated with rivers because of the breeding habitat of its vector, not because it is transmitted by drinking river water.