Onchocerciasis

Onchocerciasis is a chronic parasitic infection that primarily affects the skin and eyes, leading to severe itching, skin disfigurement, and potentially blindness, greatly impacting the quality of life and economic productivity in endemic areas.

Causative Agent and Transmission: Onchocerciasis is caused by the parasitic worm Onchocerca volvulus. It is transmitted to humans through the bite of infected blackflies (Simulium spp.), which breed in fast-flowing rivers and streams, primarily in Africa, as well as in some parts of Central and South America and the Middle East. The blackflies breed in fast-flowing rivers and streams, mostly in remote villages located near fertile land where people rely on agriculture.

Lifecycle and Infection: Once the larvae are transmitted to humans, they mature into adult worms within subcutaneous nodules in the body. These adults can live for up to 15 years. Female worms produce thousands of microscopic larvae (microfilariae) that migrate through the skin and eyes.

Skin Manifestations: The skin becomes heavily infested with the larvae, leading to severe itching, rashes, and skin discoloration. Over time, chronic skin changes such as thickening and loss of elasticity (often called "lizard skin") can occur.

Eye Disease and Blindness: One of the most severe effects of Onchocerciasis is eye disease, which can lead to visual impairment and ultimately blindness. The larvae migrate to the eyes, causing inflammation in different parts of the eye, leading to lesions on the cornea and, eventually, to irreversible blindness.

Nodules under the Skin: The presence of adult worms is often marked by palpable nodules under the skin, usually non-painful. These nodules can be surgically removed to reduce the number of circulating larvae.

Socio-Economic Impact: Like lymphatic filariasis, Onchocerciasis has significant social and economic impacts, especially in affected rural communities. The risk of blindness can hinder the ability to work and lead to increased dependency within communities.

Prevention and Control: Efforts to control Onchocerciasis focus on eliminating the blackfly vector through insecticide spraying and on mass drug administration, mainly with ivermectin, which kills the larvae, and prevents blindness.

Global Health Initiatives: There have been significant efforts by global health organizations to control and aim for the elimination of Onchocerciasis, especially in Africa. These programs have had considerable success in reducing the incidence of the disease and the associated blindness.

275 maps found/sites/default/files/upload/ESPEN_NTD_Data_Dictionary.xlsx
Regionsort descending Program stage Years Portrait PDFs Landscape PDFs Data
Western Africa MDA/PC coverage (Geographic coverage) 2016 Download map png Download map png
Western Africa MDA/PC rounds (Therapeutic coverage) 2013 - 2019 Download map png Download map png
Western Africa Mapping Surveys (Skin Biopsy) 2014 - 2015 Download map png
Western Africa MDA/PC rounds (Geographic coverage) 2013 - 2020 Download map png Download map png
Western Africa Endemicity 2020 Download map png Download map png
Western Africa MDA/PC coverage (Geographic coverage) 2019 Download map png Download map png
Western Africa Endemicity 2013 Download map png Download map png
Western Africa MDA/PC rounds (Geographic coverage) 2013 - 2015 Download map png Download map png
Western Africa MDA/PC coverage (Therapeutic coverage) 2016 Download map png Download map png
Western Africa MDA/PC coverage (Therapeutic coverage) 2020 Download map png Download map png
Western Africa MDA/PC coverage (Geographic coverage) 2018 Download map png Download map png
Western Africa MDA/PC rounds (Therapeutic coverage) 2013 - 2015 Download map png Download map png
Western Africa Mapping Surveys (Nodule Palpation) 1989 - 2014 Download map png
Western Africa MDA/PC rounds (Therapeutic coverage) 2013 - 2020 Download map png Download map png
Western Africa Endemicity 2018 Download map png Download map png
Western Africa Impact Assessment (Skin Biopsy) Download map png
Western Africa MDA/PC rounds (Geographic coverage) 2013 - 2019 Download map png Download map png
Western Africa MDA/PC coverage (Therapeutic coverage) 2018 Download map png Download map png
Western Africa Endemicity 2019 Download map png Download map png
Western Africa MDA/PC coverage (Geographic coverage) 2015 Download map png Download map png
Western Africa MDA/PC coverage (Therapeutic coverage) 2019 Download map png Download map png
Western Africa Endemicity 2016 Download map png Download map png
Western Africa MDA/PC coverage (Therapeutic coverage) 2014 Download map png Download map png
Western Africa MDA/PC rounds (Historical MDA) 2000 - 2022 Download map png Download map png
Western Africa MDA/PC coverage (Geographic coverage) 2017 Download map png Download map png
Western Africa MDA/PC rounds (Geographic coverage) 2013 - 2022 Download map png Download map png
Western Africa MDA/PC rounds (Therapeutic coverage) 2013 - 2022 Download map png Download map png
Western Africa MDA/PC coverage (Geographic coverage) 2022 Download map png Download map png
Western Africa Endemicity 2014 Download map png Download map png
Western Africa MDA/PC coverage (Therapeutic coverage) 2017 Download map png Download map png
Western Africa Endemicity 2022 Download map png Download map png
Western Africa MDA/PC coverage (Therapeutic coverage) 2022 Download map png Download map png
Western Africa MDA/PC coverage (Geographic coverage) 2013 Download map png Download map png
Western Africa MDA/PC coverage (Therapeutic coverage) 2021 Download map png Download map png
Western Africa Endemicity 2021 Download map png Download map png
Western Africa Endemicity 2015 Download map png Download map png
Western Africa MDA/PC rounds (Historical MDA) 2000 - 2021 Download map png Download map png
Western Africa MDA/PC coverage (Therapeutic coverage) 2015 Download map png Download map png
Western Africa MDA/PC coverage (Geographic coverage) 2020 Download map png Download map png
Western Africa MDA/PC coverage (Geographic coverage) 2014 Download map png Download map png
Western Africa MDA/PC rounds (Geographic coverage) 2013 - 2021 Download map png Download map png
Western Africa MDA/PC rounds (Therapeutic coverage) 2013 - 2021 Download map png Download map png
Western Africa MDA/PC coverage (Geographic coverage) 2021 Download map png Download map png
Western Africa Endemicity 2017 Download map png Download map png
Western Africa MDA/PC rounds (Historical MDA) 2000 - 2020 Download map png Download map png
Western Africa MDA/PC coverage (Therapeutic coverage) 2013 Download map png Download map png
Southern Africa Endemicity 2013 Download map png Download map png
Southern Africa MDA/PC rounds (Geographic coverage) 2013 - 2020 Download map png Download map png
Southern Africa MDA/PC coverage (Therapeutic coverage) 2013 Download map png Download map png
Southern Africa MDA/PC coverage (Therapeutic coverage) 2017 Download map png Download map png
Southern Africa MDA/PC coverage (Geographic coverage) 2021 Download map png Download map png
Southern Africa MDA/PC coverage (Geographic coverage) 2016 Download map png Download map png
Southern Africa MDA/PC rounds (Therapeutic coverage) 2013 - 2020 Download map png Download map png
Southern Africa Endemicity 2014 Download map png Download map png
Southern Africa MDA/PC coverage (Therapeutic coverage) 2016 Download map png Download map png
Southern Africa MDA/PC coverage (Geographic coverage) 2018 Download map png Download map png
Southern Africa MDA/PC rounds (Historical MDA) 2000 - 2022 Download map png Download map png
Southern Africa Endemicity 2015 Download map png Download map png
Southern Africa MDA/PC rounds (Geographic coverage) 2013 - 2022 Download map png Download map png
Southern Africa MDA/PC coverage (Therapeutic coverage) 2015 Download map png Download map png
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Southern Africa MDA/PC rounds (Therapeutic coverage) 2013 - 2022 Download map png Download map png
Southern Africa Endemicity 2022 Download map png Download map png
Southern Africa MDA/PC coverage (Therapeutic coverage) 2019 Download map png Download map png
Southern Africa Endemicity 2016 Download map png Download map png
Southern Africa MDA/PC coverage (Therapeutic coverage) 2018 Download map png Download map png
Southern Africa Endemicity 2019 Download map png Download map png
Southern Africa Endemicity 2021 Download map png Download map png
Southern Africa Impact Assessment (Skin Biopsy) Download map png
Southern Africa Endemicity 2020 Download map png Download map png
Southern Africa MDA/PC coverage (Geographic coverage) 2014 Download map png Download map png
Southern Africa Endemicity 2017 Download map png Download map png
Southern Africa MDA/PC rounds (Historical MDA) 2000 - 2021 Download map png Download map png
Southern Africa Mapping Surveys (Nodule Palpation) 1998 - 2007 Download map png
Southern Africa MDA/PC coverage (Therapeutic coverage) 2014 Download map png Download map png
Southern Africa MDA/PC rounds (Therapeutic coverage) 2013 - 2015 Download map png Download map png
Southern Africa MDA/PC rounds (Geographic coverage) 2013 - 2021 Download map png Download map png
Southern Africa MDA/PC coverage (Geographic coverage) 2019 Download map png Download map png
Southern Africa MDA/PC coverage (Geographic coverage) 2022 Download map png Download map png
Southern Africa MDA/PC rounds (Therapeutic coverage) 2013 - 2021 Download map png Download map png
Southern Africa MDA/PC coverage (Geographic coverage) 2013 Download map png Download map png
Southern Africa MDA/PC coverage (Therapeutic coverage) 2022 Download map png Download map png
Southern Africa MDA/PC rounds (Geographic coverage) 2013 - 2019 Download map png Download map png
Southern Africa MDA/PC rounds (Historical MDA) 2000 - 2020 Download map png Download map png
Southern Africa MDA/PC rounds (Therapeutic coverage) 2013 - 2019 Download map png Download map png
Southern Africa MDA/PC coverage (Therapeutic coverage) 2021 Download map png Download map png
Southern Africa Endemicity 2018 Download map png Download map png
Southern Africa MDA/PC coverage (Geographic coverage) 2020 Download map png Download map png
Southern Africa MDA/PC coverage (Geographic coverage) 2017 Download map png Download map png
Southern Africa MDA/PC rounds (Geographic coverage) 2013 - 2015 Download map png Download map png
Central Africa MDA/PC coverage (Geographic coverage) 2015 Download map png Download map png
Central Africa Endemicity 2021 Download map png Download map png
Central Africa MDA/PC coverage (Therapeutic coverage) 2013 Download map png Download map png
Central Africa MDA/PC rounds (Geographic coverage) 2013 - 2022 Download map png Download map png
Central Africa MDA/PC coverage (Therapeutic coverage) 2020 Download map png Download map png
Central Africa MDA/PC coverage (Therapeutic coverage) 2015 Download map png Download map png
Central Africa MDA/PC rounds (Therapeutic coverage) 2013 - 2015 Download map png Download map png
Central Africa Endemicity 2016 Download map png Download map png
Central Africa MDA/PC coverage (Geographic coverage) 2017 Download map png Download map png

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2205 maps found/sites/default/files/upload/ESPEN_NTD_Data_Dictionary.xlsx
Regionsort descending Location Program stage Years Portrait PDFs Landscape PDFs Data
Western Africa Niger MDA/PC coverage (Therapeutic coverage) 2020 Download map png Download map pdf Download map png Download map pdf
Western Africa Togo Endemicity 2018 Download map png Download map pdf Download map png Download map pdf
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Western Africa Nigeria MDA/PC rounds (Therapeutic coverage) 2013 - 2022 Download map png Download map pdf Download map png Download map pdf
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Western Africa Togo MDA/PC rounds (Geographic coverage) 2013 - 2018 Download map png Download map pdf Download map png Download map pdf
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Western Africa Cape Verde MDA/PC rounds (Therapeutic coverage) 2013 - 2022 Download map png Download map pdf Download map png Download map pdf
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Western Africa Nigeria Mapping Surveys (Nodule Palpation) 1989 - 2011 Download map png Download map pdf
Western Africa Senegal MDA/PC coverage (Geographic coverage) 2013 Download map png Download map pdf Download map png Download map pdf
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Western Africa Niger MDA/PC rounds (Therapeutic coverage) 2013 - 2021 Download map png Download map pdf Download map png Download map pdf
Western Africa Liberia MDA/PC rounds (Therapeutic coverage) 2013 - 2022 Download map png Download map pdf Download map png Download map pdf
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Western Africa Nigeria MDA/PC coverage (Geographic coverage) 2013 Download map png Download map pdf Download map png Download map pdf
Western Africa Benin MDA/PC rounds (Therapeutic coverage) 2013 - 2015 Download map png Download map pdf Download map png Download map pdf
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Western Africa Niger MDA/PC rounds (Geographic coverage) 2013 - 2020 Download map png Download map pdf Download map png Download map pdf
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Western Africa Guinea-Bissau MDA/PC coverage (Geographic coverage) 2019 Download map png Download map pdf Download map png Download map pdf
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Western Africa Cote d'Ivoire MDA/PC coverage (Therapeutic coverage) 2018 Download map png Download map pdf Download map png Download map pdf
Western Africa The Gambia MDA/PC coverage (Therapeutic coverage) 2017 Download map png Download map pdf Download map png Download map pdf
Western Africa Benin MDA/PC coverage (Geographic coverage) 2019 Download map png Download map pdf Download map png Download map pdf
Western Africa Mauritania MDA/PC coverage (Geographic coverage) 2013 Download map png Download map pdf Download map png Download map pdf
Western Africa Niger MDA/PC coverage (Geographic coverage) 2014 Download map png Download map pdf Download map png Download map pdf
Western Africa Mali MDA/PC coverage (Geographic coverage) 2015 Download map png Download map pdf Download map png Download map pdf
Western Africa Guinea-Bissau MDA/PC rounds (Geographic coverage) 2013 - 2019 Download map png Download map pdf Download map png Download map pdf
Western Africa Cape Verde MDA/PC rounds (Historical MDA) 2000 - 2020 Download map png Download map pdf Download map png Download map pdf
Western Africa Cape Verde Endemicity 2016 Download map png Download map pdf Download map png Download map pdf
Western Africa Togo Endemicity 2022 Download map png Download map pdf Download map png Download map pdf
Western Africa Cape Verde Endemicity 2014 Download map png Download map pdf Download map png Download map pdf
Western Africa Liberia MDA/PC coverage (Therapeutic coverage) 2015 Download map png Download map pdf Download map png Download map pdf

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