In this study, two groups of volunteers will be exposed to malaria through the bites of infected mosquitoes. In one group, volunteers will be randomly assigned to one of 5 arms. Each of these arms will receive a different dose of Malarone®, a drug known to prevent malaria when taken daily. Each of these doses will be lower than the maximum approved dose of this medicine. The other group will not be treated with any drug that could prevent symptoms or infection.~After exposure, both groups will be monitored for a period of approximately 3 months to see if they develop symptoms of malaria. Any subjects who do so will be treated with appropriate medications. Subjects in both groups will have their blood checked regularly during this period for the presence of malaria parasites. At the completion of the study, results will be analyzed to determine whether any of the doses of Malarone might effectively prevent malaria if taken weekly rather than daily.
The purpose of this study is to determine whether Malarone ®, which is a drug approved to prevent malaria when taken daily, will still effectively prevent malaria if taken weekly.