The World Health Organisation (WHO) has congratulated Niger for having met the criteria for onchocerciasis elimination, making it the fifth country globally and the first country in Africa to be acknowledged by WHO for interrupting transmission of the parasite Onchocerca volvulus.
“Eliminating a disease is a significant achievement that requires tireless dedication,” stated Dr Tedros Adhanom Ghebreyesus, WHO Director-General. “I congratulate Niger for its commitment to liberating its population from this blinding, stigmatising illness that causes so much human suffering among the poorest. This success is yet another testament to the remarkable strides we have made against neglected tropical diseases and offers hope to other nations still battling onchocerciasis, demonstrating that elimination is possible.”
Onchocerciasis, commonly known as river blindness, is a parasitic disease and is the second leading infectious cause of blindness worldwide, after trachoma. It is transmitted to humans through the bites of infective black flies, primarily found in riverine areas. The disease primarily affects rural populations in sub-Saharan Africa and Yemen, with smaller endemic areas found in parts of Latin America.
Effective country-led efforts and partnerships
Between 1976 and 1989, under the umbrella of the WHO Onchocerciasis Control Programme in West Africa (OCP), Niger undertook vector control measures by spraying insecticides that significantly decreased levels of onchocerciasis transmission. Following the donation of ivermectin by Merck, Sharpe & Dohme (MSD), areas still affected by lymphatic filariasis (LF) underwent mass drug administration (MDA) with ivermectin and albendazole from 2008 to 2019, followed by surveillance. Since ivermectin is effective against both diseases, and areas targeted for LF MDA were also endemic for onchocerciasis, this intervention also contributed to interrupting the transmission of the Onchocerca volvulus parasite.
Niger started preliminary assessments on interruption of onchocerciasis transmission in 2014 after stopping LF MDA in most areas. This was followed by entomological and epidemiological surveys which revealed that the combination of medicine and vector control had successfully eliminated transmission of onchocerciasis, as evidenced by the reduction in prevalence from approximately 60% to 0.02%.
In addition to the vector control interventions and the medicines donated by MSD, a key factor contributing to Niger’s success is the partnership between the Nigerien government, WHO and nongovernmental organisations, which has helped mobilise resources and technical support. Continuous monitoring of the disease’s prevalence and its impact has enabled timely adjustments in strategies and ensured the effectiveness of interventions.
“Onchocerciasis has long caused immense human suffering. It has also impeded the economic development of affected communities, driving people away from rivers, which are often lifelines for livelihoods,” says Dr Matshidiso Moeti, WHO Regional Director for Africa. “Niger’s success ends this burden for its people. It also positions Niger as a model for the elimination of neglected tropical diseases in Africa. The country previously demonstrated its leadership in public health, by eliminating Guinea-worm disease in 2013. Today, it takes another historic step forward.”
Global progress
Globally, 54 countries have eliminated at least one neglected tropical disease.
Niger joins four other countries that have been verified by WHO for eliminating onchocerciasis, all in the Region of the Americas: Colombia (2013), Ecuador (2014), Guatemala (2016) and Mexico (2015).
In the WHO African Region, 21 countries have eliminated at least one neglected tropical disease. Onchocerciasis is the second neglected tropical disease eliminated in Niger: the country was certified free of dracunculiasis (Guinea-worm disease) transmission in 2013.
In a related development, the WHO has lauded Guinea for eliminating the gambiense form of human African trypanosomiasis as a public health problem. This form of human African trypanosomiasis, the only type transmitted in Guinea, is the first neglected tropical disease to be eliminated in the country. The news marks an important achievement in this public health field on the eve of the world Neglected Tropical Diseases Day, marked on January 30.
“Today’s announcement is both a testament to the global progress against neglected tropical diseases and a beacon of hope for nations still battling human African trypanosomiasis,” said Dr Ghebreyesus.
Human African trypanosomiasis (HAT), or sleeping sickness, is a vector-borne parasitic disease caused by infected tsetse flies. Symptoms include fever, headaches, joint pain and, in advanced stages, neurological symptoms like confusion, disrupted sleep patterns and behavioural changes.
Effective country investments and partnerships
In the 1990s, HAT resurged along Guinea’s coast due to increased human activity in mangroves, driven by Conakry’s economic and population growth. In response to the critical threat posed by HAT, Guinea’s Ministry of Health and Public Hygiene established the National Programme for the Control of HAT in 2002, with support from WHO and the Institut de Recherche pour le Développement (IRD), and later from partners such as the Drugs for Neglected Diseases initiative and the Institut Pasteur de Guinée. The programme began with mass medical screenings to diagnose and treat cases effectively, marking a crucial step in controlling the disease.
The programme introduced vector control interventions in 2012 aiming to interrupt contact between people and tsetse flies. Initially implemented in the Boffa-East area, this strategy expanded nationwide by 2016, with nearly 15,000 impregnated mini-screens (with insecticides to attract and kill the tsetse flies) deployed annually.
However, Guinea faced significant challenges in its HAT elimination efforts during the Ebola outbreak and COVID-19. From 2013 to 2015, the Ebola epidemic caused a suspension of medical activities, leading to a resurgence in HAT cases. In 2020, the COVID-19 pandemic posed further disruptions, but the programme adapted by implementing door-to-door HAT screening to maintain control efforts.
Collaboration with local communities played a critical role throughout these years, ensuring that interventions were culturally acceptable and widely supported. Advances in diagnostic techniques, treatment delivery, and consistent financial and technical backing from WHO and other partners bolstered the programme’s impact. As a result, Guinea successfully reduced the number of HAT cases to below the WHO threshold of 1 case per 10 000 inhabitants in all endemic areas, achieving a major milestone in its fight against this neglected tropical disease.
“The elimination of sleeping sickness is the result of many years of effort by the Guinean government, its partners and communities in the overall context of the national policy to combat all neglected tropical diseases,” said Dr Oumar Diouhé BAH, Guinea’s Minister of Health and Public Hygiene.
“The elimination of human African trypanosomiasis by Guinea is a significant public health achievement. Vulnerable families and communities can now live free of the threat posed by this potentially fatal disease,” said Dr Moeti. “I congratulate the government, health workers, partners and communities for this crucial milestone. WHO remains committed to supporting countries to eliminate human African trypanosomiasis and other neglected tropical diseases in Africa.”
With Guinea, seven other countries have been validated by WHO for eliminating the gambiense form of human African trypanosomiasis: Togo (2020), Benin (2021), Côte d’Ivoire (2021), Uganda (2022), Equatorial Guinea (2022), Ghana (2023) and Chad (2024). The rhodesiense form of the disease has been eliminated as a public health problem in one country, Rwanda, as validated by WHO in 2022.