ArticlePLoS neglected tropical diseases2021
How does onchocerciasis-related skin and eye disease in Africa depend on cumulative exposure to infection and mass treatment?
Article in PLoS neglected tropical diseases, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 11 papers.
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Who cites it
11 citing papers in PubMed, 13 citations in OpenAlex.
- Molecular characterization of filarial infections and their associated risk factors in rural community of Southeastern Gabon.Parasite epidemiology and control · 2026Article
- Modelling the impact of mass drug administration with ivermectin or moxidectin on human onchocerciasis when there is sub-optimal response of parasites to treatment.Research square · 2026Article
- Public health impact of nuisance biting blackfly (Simulium damnosum s.l.) along the Asejire dam in Southwest, Nigeria.BMC public health · 2026Article
- A GIS and field-based assessment of the ecological consequences of illegal mining (galamsey) on blackfly breeding sites in Ghana: implications for the sustainable development goals.Tropical medicine and health · 2026Article
- Modelling of onchocerciasis-associated skin and ocular disease and the impact of ivermectin treatment.Communications medicine · 2026Article
- Onchocerciasis and non-communicable diseases in the Bafut Health District, Cameroon: Knowledge, attitudes, and practices towards community-directed treatment with ivermectin.PLoS neglected tropical diseases · 2026Article
- Performance of novel onchocerciasis rapid diagnostic tests in a field setting in South Sudan.PLoS neglected tropical diseases · 2025Article
- Community's knowledge, perceptions and preventive practices on Onchocerciasis in Jimma zone, Ethiopia, formative mixed study.PLoS neglected tropical diseases · 2024Article
- Modelling morbidity for neglected tropical diseases: the long and winding road from cumulative exposure to long-term pathology.Philosophical transactions of the Royal Society of London. Series B, Biological sciences · 2023Review
- Onchocerciasis-associated epilepsy in Maridi, South Sudan: Modelling and exploring the impact of control measures against river blindness.PLoS neglected tropical diseases · 2023Article
- The burden of skin disease and eye disease due to onchocerciasis in countries formerly under the African Programme for Onchocerciasis Control mandate for 1990, 2020, and 2030.PLoS neglected tropical diseases · 2021Article
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Authors and funding
8 authors at 3 institutions in 3 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundOnchocerciasis (river-blindness) in Africa is targeted for elimination through mass drug administration (MDA) with ivermectin. Onchocerciasis may cause various types of skin and eye disease. Predicting the impact of MDA on onchocercal morbidity is useful for future policy development. Here, we introduce a new disease module within the established ONCHOSIM model to predict trends over time in prevalence of onchocercal morbidity.
methodsWe developed novel generic model concepts for development of symptoms due to cumulative exposure to dead microfilariae, accommodating both reversible (acute) and irreversible (chronic) symptoms. The model was calibrated to reproduce pre-control age patterns and associations between prevalences of infection, eye disease, and various types of skin disease as observed in a large set of population-based studies. We then used the new disease module to predict the impact of MDA on morbidity prevalence over a 30-year time frame for various scenarios.
resultsONCHOSIM reproduced observed age-patterns in disease and community-level associations between infection and disease reasonably well. For highly endemic settings with 30 years of annual MDA at 60% coverage, the model predicted a 70% to 89% reduction in prevalence of chronic morbidity. This relative decline was similar with higher MDA coverage and only somewhat higher for settings with lower pre-control endemicity. The decline in prevalence was lowest for mild depigmentation and visual impairment. The prevalence of acute clinical manifestations (severe itch, reactive skin disease) declined by 95% to 100% after 30 years of annual MDA, regardless of pre-control endemicity.
conclusionWe present generic model concepts for predicting trends in acute and chronic symptoms due to history of exposure to parasitic worm infections, and apply this to onchocerciasis. Our predictions suggest that onchocercal morbidity, in particular chronic manifestations, will remain a public health concern in many epidemiological settings in Africa, even after 30 years of MDA.
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