Introduction | Lifecycle | Distribution / Map* | Treatment | Loiasis

Distribution of Onchocerciasis Worldwide

Onchocerciasis is endemic in 28 African countries, one country in the Middle East, and six countries in Latin America. More than 99% of all cases of onchocerciasis and onchocerciasis-related blindness in the world are found on the African continent.¹ The distribution of onchocerciasis in the Middle East and Latin America is focal. In these two regions, the burden of disease represents less than 1% of the global problem; however onchocerciasis remains a significant cause of morbidity. 



The 26 countries in Africa where mass treatment with Mectizan is indicated and ongoing for onchocerciasis, as of the end of 2005. Countries are color coded according to their inclusion in the former OCP (green) or APOC (yellow) regions. As of the end  of 2005, there were mass treatment programs with Mectizan for onchocerciasis in all 26 African countries where such intervention is epidemiologically justified. These 26 countries, plus Niger and Mozambique, are eligible for Mectizan combined with albendazole for national programs to eliminate Lymphatic Filariasis. This map is reproduced with permission of the Annals of Tropical Medicine and Parasitology, 2006, Volume 100, pages 733-46.




Foci in Latin America (OEPA region) where onchocerciasis is endemic and where mass treatment with Mectizan is indicated and ongoing, as of the end of 2005. In Latin America (OEPA region), as of the end of 2005, all onchocerciasis endemic foci were indicated for twice-yearly mass treatment with Mectizan, regardless of endemicity, as a strategy for the elimination of onchocercal morbidity and transmission of infection. This map is reproduced with permission of the Annals of Tropical Medicine and Parasitology, 2006, Volume 100, pages 733–46.

Distribution of Onchocerciasis and Lymphatic Filariasis in Africa

In Africa, 40 countries are believed to be endemic for lymphatic filariasis.² The extent of overlap between LF and onchocerciasis within these African countries is currently unknown.

References

1. World Health Organization. Onchocerciasis and its control, report of a WHO Expert Committee on Onchocerciasis Control. Geneva: World Health Organization; 1995. Technical Report Series No.: 852.

2. World Health Organization. Lymphatic filariasis. Wkly Epidemiol Rec 2001;76(20): 149-154.