Thick and thin smears will be prepared on the same slide and stained in 10% Giemsa solution (pH 7.2) for 10-15 minutes. All smears must be read to 100 fields before they can be declared negative. Species will be confirmed on the thin smear. Quantification of P. falciparum asexual parasitaemia on the thick smear will be performed according to the WHO protocol26. Parasites will be counted against at least 200 white blood cells/leucocytes (WBC), and the parasite density (expressed in parasites per µL of blood) will be calculated assuming a normal level of 8000 WBC/µL: