The Noguchi Memorial Institute for Medical Research (NMIMR) hosted a seminar on “Progress towards onchocerciasis elimination in Ghana and associated challenges” on Tuesday, April 14, 2026, at the Institute Conference Hall. The seminar was delivered by Dr. Kwadwo Kyereme Frempong, Medical Entomologist and Research Fellow in the Department of Parasitology.

The presentation provided a comprehensive overview of Ghana’s progress towards eliminating onchocerciasis, while highlighting critical challenges that continue to threaten the attainment of the 2030 elimination target.

Onchocerciasis, commonly known as river blindness, remains one of the leading infectious causes of blindness globally and is transmitted through repeated bites of infected Simulium blackflies, particularly in communities located near fast-flowing rivers (breeding sites for vector). It was noted that disease prevalence is highest in communities closest to breeding sites, with transmission intensity declining with distance away from breeding site.

The seminar outlined the historical burden of the disease in Ghana and the sustained efforts under the national Neglected Tropical Diseases (NTD) Programme. Emphasis was placed on mass drug administration (MDA) with ivermectin, which has significantly reduced disease prevalence in endemic communities.

Providing historical context, Dr. Frempong indicated that Ghana was among the first countries to participate in early ivermectin trials between 1987 and 1991, following support from Merck & Co. He traced the evolution of control strategies from the mobile team approach of the early 1990s—characterised by high cost, limited coverage, and a top-down structure—to the current community-directed treatment with ivermectin model, which has improved access and treatment coverage.

He noted that ivermectin plays a critical role in controlling transmission by killing microfilariae in the skin and preventing their reproduction by the adult female worm, although it does not eliminate the adult worms. This, he noted, necessitates sustained treatment over several years to effectively interrupt transmission.

Significant progress has been made over the years, including a sharp decline in microfilariae prevalence from over 60 per cent in the pre-control period to less than one per cent in many endemic communities. In addition, over 100 million ivermectin tablets have been distributed, with treatment coverage consistently maintained above 80 per cent in recent years (data from the NTD programme). The number of endemic districts requiring treatment has also reduced considerably.

Despite these gains, the presentation highlighted a few persistent challenges. Human-related factors such as migration, cross-border transmission, hard-to-reach populations, and low community participation continue to affect programme implementation. The 2023 blackfly invasion in Accra, a previously non-endemic area, was also cited as a concern, potentially linked to environmental changes such as illegal mining activities which could affect vector distribution.

Operational challenges, including uncertainties in funding for subsequent rounds of MDA, delays in securing waivers for drug clearance, and high attrition among community drug distributors, particularly in urban areas, were also discussed.

Vector-related challenges remain significant, with blackflies capable of travelling considerable distances, thereby complicating control efforts and the ability to accurately identify transmission zones.

Concerns were also raised about possible genetic changes in the parasite as a result of prolonged treatment, underscoring the need for continuous monitoring and research to inform control strategies.

The seminar concluded with an interactive session, where participants raised questions on sustaining treatment gains and preventing resurgence. In response, Dr. Frempong emphasized the need for strengthened surveillance systems, improved community engagement, and enhanced cross-border collaboration. The importance of integrating innovative molecular and genetic tools to support monitoring and guide interventions was also highlighted.