The Mpamba-Nkusi focus is located in the northern part of the Kibale district in Uganda. It covers an area of about 300 km2. There is a dry and a wet season, and the zone is characterized by high vegetation (elephant grass), and forest galleries along the watercourses.
There are several perennial rivers (Mpamba, Nkusi, Ntengo, Mutunguru, Nyabwegyereka, Rwabutuju and Murungu) and a few tributaries running through the Mpamba-Nkusi focus. Simulium neavei is the vector of onchocerciasis in this focus.
Large-scale ground larviciding started in 2003 and ended in 2004. Since 2007, Simulium naevei has virtually disappeared in Mpamba-Nkusi.
Ivermectin has been distributed since 1992 by Sight Savers International. Community-directed treatment with ivermectin was adopted in 1999. Reinforcement of community-directed treatment with ivermectin is expected to lead to rapid elimination of onchocerciasis.