PIP: Onchocerciasis is an endemic disease in 37 countries (in Africa, in the Americas, and in Yemen). It infects at least 17.7 million people and causes visual impairment in 500,000 and blindness in another 270,000. It is transmitted by black flies that breed in rapidly flowing rivers and streams. As response to an endemic disease, programs have focused on the control of onchocerciasis transmission. In Africa, the African Programme for Onchocerciasis Control is based on an ivermectin-distribution strategy designed to control the skin and eye disorders that result from heavy infections. By contrast, the strategy of the African Onchocerciasis Control Program is a vector control to completely interrupt the transmission cycle of the parasite by applying larvicide to riverine breeding sites. In the Americas, another strategy being implemented is to use ivermectin more than once a year, not only to stop progression of disease, but also to interrupt transmission. Moreover, the global lymphatic-filariasis initiative aims to halt transmission of lymphatic filariasis in endemic African communities by annual mass administration of single-dose combination therapy with albendazole and Mectizan.