This study is a phase 2b, placebo controlled, randomized, blinded study of the efficacy of WR 238605, a new primaquine analog, compared to placebo as chemosuppression of P. falciparum malaria in Nyanza Province, western Kenya.

Inclusion Criteria:

1. Healthy subjects (male or female)
2. Age of 18-55 years
3. Residing in one of the study villages of the Nyanza Province for the entire study

Exclusion Criteria:

1. Any cardiovascular, liver, neurologic, or renal functional abnormality which in the opinion of the clinical investigators would place the subject at increased risk of an adverse event or confuse the result.
2. Female subjects who were pregnant (Positive serum / plasma -HCG as tested within 48 hours of first drug administration).
3. Use of antimalarial drugs not prescribed by study physicians within 2 weeks of study drug initiation.
4. Clinically significant abnormalities (including but not limited to abnormal hepatic or renal function) as determined by history, physical and routine blood chemistries and complete blood count.
5. Known hypersensitivity to any study drug.
6. Unwilling to remain in area and report for drug administration and blood drawing during the duration of the study.
7. Glucose 6 Phosphate Dehydrogenase (G6PD) deficiency.