Date of Defense

Fall 12-5-2003


Biological Sciences

First Advisor

Leonard Beuving, Biology

Second Advisor

Rob Eversole, Biology

Third Advisor

John Stout, Biology




Onchocerca volvulus is a nematode that infects humans in tropical countries and causes Onchocerciasis. This disease presents a variety of problems for the infected individual, not only physical symptoms. In addition to physical effects such as blindness, weight loss, and skin deformities, Onchocerciasis patients also experience difficulty in their social and economic life. The commonly used treatment for Onchocerciasis is ivermectin, which is distributed at least once annually to infected persons with the help of the African Program for Onchocerciasis Control (APOC). Ivermectin has been shown by others to damage O. volvulus larvae, or microfilariae, but the goal of our study was to show that ivermectin also plays a role in the degeneration of the adult parasite. The authors examined the cellular immune response in parasite samples removed from ivermectin-treated patients from both Ecuador and Guatemala. Viable nodules were those that contained healthy worms, or degenerating worms that were still producing microfilariae. Non-viable nodules were those that contained dead worms. The viable samples consisted largely of a mixed reaction in an attempt to destroy the nematode. The non-viable nodules were infiltrated mostly with lymphocytes, acting to clean up and repair the damaged tissues. From this data, our study found that treatment with ivermectin effectively controls the adult parasite and aids in its degeneration and death.


Charles Mackenzie, Biology

Access Setting

Honors Thesis-Campus Only