Study Evaluating Orally Administered Moxidectin In Subjects With Onchocerca Volvulus Infection

Inclusion Criteria: 1. Written, signed (or thumb-printed), and dated informed consent 2. Aged 18 to 60 years, inclusive 3. Body weight ≥ 40 kg for women and ≥ 45 kg for men 4. Nonpregnant, nonbreastfeeding women. Women of child bearing potential must agree to use birth control during the first 150 days after treatment. 5. Healthy, as determined by a physician on the basis of a physical examination, ECG, and a thorough review of the medical history and clinical laboratory results 6. Adequate hematologic, renal, and hepatic function 7. Skin microfilarial density within the required range for the cohort Exclusion Criteria: 1. Participation in any studies other than purely observational ones, within 4 weeks before test article administration. 2. Any vaccination within 4 weeks before test article administration 3. Acute infection requiring therapy within the last 10 days before test article administration 4. Administration of any medication (with the exception of medication required to treat any reactions during the screening fluorescein angiography (chlorpheniramine) or paracetamol) or herbal preparation within 10 days prior to test article administration or any condition currently requiring regular medication 5. Clinically significant ECG abnormalities or history of cardiac abnormality 6. Past or current history of neurological or neuropsychiatric disease or epilepsy 7. Subjects with orthostatic hypotension at the screening evaluation 8. History of drug or alcohol abuse or regular use of ≥ 3 cigarettes per day 9. Use of alcohol or other drugs of abuse within 72 hours before test article administration 10. Any condition, in the investigator's opinion, that places the subject at undue risk 11. Subjects who have donated blood within 8 weeks before study entry 12. Subjects with ocular onchocerciasis in cohorts intended to enroll subjects with mild infection. Ocular onchocerciasis is defined by the presence of live or dead microfilariae, onchocercal punctate opacities, onchocercal lesions of the posterior segment or lesions that mimic those seen in onchocerciasis. 13. Subjects with hyperreactive onchodermatitis 14. Antifilarial therapy within the previous 5 years 15. Coincidental infection with Loa Loa 16. Female subjects of childbearing potential with a contraindication to DMPA if not on Norplant 17. Any other condition which the investigator feels would exclude the subject from the study