Oral Tafenoquine Plus Standard of Care Versus Placebo Plus Standard of Care for Babesiosis

Inclusion Criteria: * Male or female, aged ≥ 18 years. * Laboratory confirmed infection with Babesia. * Exhibiting at least one self-reported clinical symptoms of babesiosis. * Able and willing to give written informed consent. * Expected to be hospitalized at the time of or following informed consent and still hospitalized on the day of randomization and start of investigational products. * Willing to complete the study activities and assessments. * Must agree not to enroll in another study of an investigational agent prior to completion of the study. * Able to take oral medications. * If female of reproductive age, must agree to use an acceptable method of birth control. * Adequate venous access. * Blood hemoglobin ≥ 7 g/dL. Exclusion Criteria: * Have any contraindications to TQ. * Have any contraindication for azithromycin or atovaquone. * Any concomitant significant illness unrelated to babesiosis. * Receipt of any experimental treatment for babesiosis. * Taking any excluded concomitant medication. * Current or planned treatment with quinine while participating in the study. * Positive pregnancy test. * If A/A was initiated more than 48h prior to randomization and parasitemia is not \>1%. * Azithromycin or atovaquone administered in the last 12 months to treat babesiosis, and, in the opinion of the investigator, high likelihood that current infection represents a relapse or continuation of disease.