Malaria, Cerebral

The goal of this clinical trial is to evaluate the safety of a single intravenous dose of DON in healthy adults, adults with uncomplicated malaria, and children 12 months-14 years old with clinically defined Cerebral Malaria. The main objectives are: * Evaluate the safety of a single intravenous dose of DON in healthy adults and adults with uncomplicated malaria ( Part 1) * Determine the safety of a single dose of DON in children 12 months-14 years old with World Health Organization (WHO) clinically defined CM (Part 2 :Cohort 1-4) * Determine the pharmacokinetic (PK) profile of a single dose of DON in healthy adults, adults with uncomplicated malaria and children with CM (Part 1, and Cohorts 1-4 of Part 2) * Determine if administration of a single intravenous dose of DON as an adjunctive therapy in children with CM is associated with improved intracerebral blood flow dynamics on transcranial doppler (TCD) (Part 2 :Cohort 1-4) * Determine if administration of a single intravenous dose of DON as an adjunctive therapy in children with CM is associated with a reduction in brain volume score on magnetic resonance imaging (MRI) (Part 2 :Cohort 1-4) * Determine if administration of a single intravenous dose of DON as an adjunctive therapy in children with cerebral malaria is associated with changes in electroencephalogram (EEG) pattern (Part 2 :Cohort 1-4) * Exploratory: Explore the metabolic mechanisms of action of adjunctive DON in children with CM Healthy adult participants will receive: * anti-emetic ondansetron * one dose of DON Adults with uncomplicated malaria will receive: * anti-emetic ondansetron * one dose of DON * artemisinin-combination therapies per Malawi Ministry of Health guidelines Pediatric participants will receive: * one dose of DON * anti-emetic ondansetron and per Malawi Ministry of Health guidelines: * enteral lumefantrine-artemether therapy, and * artesunate therapy