Loiasis is a filarial disease caused by Loa loa in Central and West Africa. This parasite is less pathogenic than Lymphatic Filariasis (LF) or Onchocerciasis (Oncho). However, it represents a serious barrier to LF and Oncho elimination and control programs in Africa. This is because medications such as Ivermectin and Diethylcarbamazine used in MDA programs can cause serious adverse events (SAEs) such as coma and death in persons with heavy L. loa infections. Oncho- and LF-endemic areas overlap extensively with forested regions in Africa that are highly endemic for loiasis (see map).
The risk of SAE’s related to MDA in persons with loiasis has prevented implementation of MDA programs for LF and Oncho in many areas in sub-Saharan Africa. Research is urgently needed to identify ways to address this problem.