2.3. Recurrent parasitaemia In case of recurrent falciparum malaria blood will be taken for cryopreserving parasites, antimalarial drug levels, for assessment of genotyping and gene expression (22mL). The maximum volume taken from children < 10yrs is 10mL. In case of recurrent parasitaemia, more than 3 days after the initiation of treatment, DNA will be isolated from from blood samples. Paired samples from every patient, taken at initial enrolment and at time of recurrence, will then be genotyped on the basis of polymorphisms in the genes for the merozoite surface proteins MSP-2 and MSP-1 and GLURP.