Summary of characteristics of participants living in Dedza and Mangochi Districts.

Values are percentages of total enrolled population. Brackets show 95% confidence intervals. 1 Pearson's Chi-square test for categorical variables and Mann-Whitney U test for continuous variables. P values less than 0.05 are in bold. 2 Taking into account samples in which Plasmodium was detected by PCR but not by microscopy (i.e. present only at sub-microscopic levels), for which density was assumed to be 10 parasites per ��l of blood for each species detected. 3 People treated with anti-malarials during the study were those with high parasite densities or at greater risk of progression to severe malaria, as defined in Enrolment and sample collection section of Materials and Methods.