The purpose of this study is to determine the efficacy of sulfadoxine-pyrimethamine plus artesunate versus sulfadoxine-pyrimethamine alone in the treatment of uncomplicated malaria.

Resistance of Plasmodium falciparum to anti-malarial drugs is a serious impediment to the control of malaria. In order to facilitate formulation of effective regional drug policies and to provide a database for decision-making on the implementation of combination therapy (CAT), it is essential that the in vivo response to CAT be investigated. In the South East African Combination Anti-malarial Therapy (SEACAT) evaluation, there is a comprehensive evaluation of the phased introduction of combination anti-malarial therapy in Mozambique. As a component of this evaluation, in selected Mozambique sites where intensity of malaria transmission is high, a direct parallel group comparison of monotherapy (SP) with CAT (artesunate plus SP) will be conducted according to this protocol.

Inclusion Criteria:

• Male or female, older than 12 months.
• Weight > 10 kg.
• Diagnoses of pure uncomplicated acute P. falciparum malaria parasitaemia of up to 500 000 asexual parasite/mcl blood with axillary temperature of greater than or equal to 37.5°C or history of fever (defined as within the previous 24 hours).
• Documented informed consent.
• Lives close enough to the study site for reliable follow up.

Exclusion Criteria:

• Has received anti-malarial treatment in the past 7 days.
• Is infected with other malarial species (such subjects may be excluded retrospectively from the analysis).
• Severely ill (based on WHO Criteria for severe malaria ) or if patient is considered, in the opinion of the investigator or designee, to have moderately severe malaria (e.g. prostrate, repeated vomiting, dehydrated) or other danger signs.
• Has received cotrimoxazole, trimethoprim, chloramphenicol, folate or tetracyclines (including doxycycline) in the past 7 days or is likely to require these during the study period.
• History of G6PD deficiency.
• Is pregnant or breastfeeding.
• Has a history of allergy to any of the study drugs (including other sulphonamides e.g. cotrimoxazole, other artemisinin derivatives e.g. co-artemether).
• Serious underlying disease that in the opinion of the clinic team and/or Principal Investigator would make the patient unsuitable for the study in terms of their safety or study analysis.