In News:

The World Health Organization (WHO) officially verified Niger as the first country in the African Region and the fifth globally to eliminate onchocerciasis (river blindness) by interrupting the transmission of the parasite Onchocerca volvulus.

What is Onchocerciasis (River Blindness)?

• A parasitic disease caused by the worm Onchocerca volvulus.
• Transmitted by infective blackflies, primarily found in riverine areas.
• Causes severe itching, disfiguring skin conditions, and irreversible blindness.
• It is the second leading infectious cause of blindness globally (after trachoma).
• Predominantly affects rural populations in sub-Saharan Africa, Yemen, and parts of Latin America.

Niger’s Elimination Strategy and Achievements:

Historical Background:

• 1976–1989: Under the WHO Onchocerciasis Control Programme (OCP), Niger used vector control via insecticide spraying, reducing disease transmission.
• 2008–2019: Mass Drug Administration (MDA) with ivermectin and albendazole was carried out, primarily for lymphatic filariasis (LF), but also effectively interrupted onchocerciasis transmission in co-endemic areas.

Assessment and Surveillance:

• 2014: Niger began preliminary assessments following the end of LF MDA.
• Entomological and epidemiological surveys confirmed disease elimination:
  • Prevalence dropped from 60% to 0.02%.
  • No ongoing transmission of O. volvulus.

Key Contributors to Success:

• Partnerships: Collaborative efforts between the Government of Niger, WHO, Merck Sharpe & Dohme (MSD), and various NGOs.
• Medicine Donation: MSD’s donation of ivermectin.
• Surveillance & Flexibility: Continuous monitoring allowed strategic adaptation.
• Previous Success: Niger was certified free of Guinea-worm disease in 2013.

Global and Regional Significance:

• Niger becomes the fifth country globally to eliminate onchocerciasis:
  • Other four countries:
    • Colombia (2013)
    • Ecuador (2014)
    • Mexico (2015)
    • Guatemala (2016) (All from the WHO Region of the Americas)
• WHO African Region:
  • 21 countries have eliminated at least one Neglected Tropical Disease (NTD).
  • Onchocerciasis is the second NTD eliminated in Niger after Guinea-worm.