Low prevalence of epilepsy and onchocerciasis after more than 20 years of ivermectin treatment in the Imo River Basin in Nigeria oleh Joseph N. F. Siewe, Chinyere N. Ukaga, Ernest O. Nwazor, Murphy O. Nwoke, Modebelu C. Nwokeji, Blessing C. Onuoha, Simon O. Nwanjor, Joel Okeke, Kate Osahor, Lilian Chimechefulam, Ann I. Ogomaka, Augustine A. Amaechi, Chika I. Ezenwa, Monika N. Ezike, Chidimma Ikpeama, Ogechi Nwachukwu, Austine I. Eriama-Joseph, Berthram E. B. Nwoke, Robert Colebunders