Status of Onchocerciasis transmission after more than a decade of mass drug administration for onchocerciasis and lymphatic filariasis elimination in central Nigeria: challenges in coordinating the stop MDA decision.

Background: This study was undertaken in five onchocerciasis/lymphatic filariasis (LF) co-endemic local government areas (LGAs) in Plateau and Nasarawa, Nigeria. Annual MDA with ivermectin had been given for 17 years, 8 of which were in combination with albendazole. In 2008, assessments indicated that LF transmission was interrupted, but that the MDA had to continue due to the uncertain status of onchocerciasis transmission.