Modeling targeted ivermectin treatment for controlling river blindness.

There is considerable host heterogeneity in exposure to onchocerciasis. We incorporate this heterogeneity into a model of onchocerciasis transmission that we use to evaluate intervention strategies targeting specific portions of the human population for treatment with ivermectin. Our model predicts that targeted allocation of ivermectin in a highly heterogeneous population will reduce the public health burden of onchocerciasis using 20-25% of the doses of untargeted allocation. Targeted allocation therefore poses significantly lower risk of adverse effects, while potentially delaying the emergence and spread of ivermectin resistance, relative to untargeted allocation.