Inclusion criteria  Children ages 6 months - 15 years Has a laboratory diagnosis of Sickle Cell Anaemia (HbSS) on haemoglobin electrophoresis, High-Performance Liquid Chromatography or Iso-electric focusing; Weighs ≥5kg; The parent has provided written consent.  Exclusion Criteria:  Known chronic disease e.g. congenital heart disease; Known red cell disorder e.g. thalassaemia, glucose-6-phosphate dehydrogenase deficiency; Known allergy to DP or SP; Receiving daily cotrimoxazole prophylaxis; Unlikely to comply with the follow-up schedule; Participating in another trial