The purpose of this study is to compare the gametocytocidal and transmission reducing activity of artesunate-amodiaquine (ASAQ) and artemether-lumefantrine-amodiaquine (ALAQ) with and without a single dose of 0.25mg/kg primaquine (PQ). Outcome measures will include infectivity to mosquitoes at 2, 7 and 14 days after treatment, gametocyte density throughout follow-up, and safety measures including haemoglobin density and the frequency of adverse events.

Full protocol available on request

Inclusion Criteria:

• Age ≥ 10 years and ≤ 50 years
• Absence of symptomatic falciparum malaria, defined by fever on enrolment
• Presence of P. falciparum gametocytes on thick blood film at a density >16 gametocytes/µL (i.e. ≥ gametocytes recorded in the thick film against 500 white blood cells)
• Absence of other non-P. falciparum species on blood film
• Haemoglobin ≥ 10 g/dL
• Individuals weighing < = 80 kg
• No evidence of acute severe or chronic disease
• Written, informed consent

Exclusion Criteria:

• Women who are pregnant or lactating (tested at baseline). Urine and/or serum pregnancy testing (β-hCG) will be used.
• Detection of a non-P. falciparum species by microscopy
• Previous reaction to study drugs / known allergy to study drugs, such as sudden high fevers, shaking or severe sore throat or ulcers in the mouth during treatment with Amodiaquine
• Current eye disease with retinal damage
• Signs of severe malaria, including hyperparasitaemia (defined as asexual parasitaemia > 100,000 parasites / µL)
• Signs of acute or chronic illness, including hepatitis
• The use of other medication (except for paracetamol and/or aspirin), including antacids, other medicines used to treat malaria, abnormal heart rhythm, depression or mental illness or HIV/AIDS, and medicines that have antibiotic/antifungal properties
• Use of antimalarial drugs over the past 7 days (as reported by the participant)
• Clinically significant illness (intercurrent illness e.g., pneumonia, pre-existing condition e.g., renal disease or HIV/AIDS, malignancy or conditions that may affect absorption of study medication e.g., severe diarrhoea or any signs of malnutrition as defined clinically)
• Signs of hepatic injury (such as nausea and/or abdominal pain associated with jaundice) or known severe liver disease (i.e., decompensated cirrhosis, Child Pugh stage B or C)
• Signs, symptoms or known renal impairment
• Clinically significant abnormal laboratory values as determined by history, physical examination, or routine blood chemistries and haematology values (laboratory guideline values for exclusion are haemoglobin < 10 g/dL, platelets < 50,000/μl, White Blood Cell count (WBC) < 2000/μl, serum creatinine >2.0mg/dL, or ALT more than 3 times the upper limit of normal for age.
• Blood transfusion in the last 90 days.
• Known Electrocardiogram (ECG) corrected QT interval of more than 450 ms
• Documented or self-reported history of cardiac conduction problems
• Documented or self-reported history of epileptic seizures

Anonymised individual participant data may be shared on a digital repository or upon reasonable request.

This is a single blind randomised controlled trial. The treating physician and staff involved with assessing all laboratory outcomes of the study are blinded, but no placebo will be used. The study pharmacist will be unblinded and responsible for randomisation and treatment administration.