GS-5734 to Assess the Antiviral Activity, Longer-Term Clearance of Ebola Virus, and Safety in Male Ebola Survivors With Evidence of Ebola Virus Persistence in Semen

Background: Some people have Ebola virus in their body for months after they recover from Ebola virus disease. Some may have health problems from the virus while others are fine. These people may be able to pass the virus to others. There are currently no drugs for people who have survived Ebola virus disease but still have the virus in their body. A new drug, GS-5734, might help get rid of Ebola virus in semen. Objective: To test if GS-5734 helps get rid of Ebola virus in semen and is safe for humans. Eligibility: Men who participated in the Ebola survivor study (PREVAIL III) and have evidence of the Ebola virus in their semen Design: Participants will be screened with: Questions Physical exam Eye exam Blood tests 2 semen samples if they have not had it tested recently Participants must live near the study site in Liberia for 6 months. Participants will be put into 1 of 2 study groups. They will have an infusion of either GS-5734 or a placebo every day for 5 days. A plastic tube is put into an arm vein. The infusion lasts 1 hour. Participants will be observed for 1 hour after. They will provide a semen sample on infusion day 4. After the infusions, participants will have 5 visits in the first month, then 1 per month for 5 more months. These include giving a blood and semen sample. Blood tests are performed before and after each infusion and the last visit (5 month visit) will also include an eye exam. When the study is over, if the study drug works and is safe, participants who got the placebo can get the study drug.