Onchocerciasis

News: Niger becomes the first country in the African Region to eliminate onchocerciasis.

About Onchocerciasis

• Onchocerciasis, or river blindness, is a parasitic disease caused by Onchocerca volvulus.
• It is the second leading infectious cause of blindness worldwide after trachoma.
• Transmission: The disease is transmitted to humans through repeated bites from infected blackflies of the Simulium genus, which are commonly found near fast-flowing rivers.
• Region Affected: Most affected populations live in rural areas of sub-Saharan Africa and Yemen, with smaller endemic regions in Latin America.
• Mode of transmission: Blackflies acquire microfilariae when they bite an infected person. These microfilariae develop inside the fly into infectious larvae over time.
  • When the infected blackfly bites another human, the larvae exit the fly and penetrate the skin to begin a new infection.
  • Infected individuals may present with no symptoms or may develop itchy rashes, eye disease, or palpable nodules under the skin.
  • Blindness typically occurs only after long-standing, intense infection.
• Diagnosis: Microscopic examination of skin snips is the most reliable method for diagnosing onchocerciasis.
• Prevention: There are no vaccines or medications that prevent infection with O. volvulus.
  • Prevention relies on avoiding blackfly bites through personal protective measures.
  • Using insect repellent, wearing long-sleeved clothing, and limiting exposure to riverside habitats can reduce the risk of infection.