Higher gametocyte production and mosquito infectivity in chronic compared to incident Plasmodium falciparum infections

Plasmodium falciparum gametocyte kinetics and infectivity may differ between chronic and incident infections. Children aged 5-10 years were recruited from an area of high malaria transmission in Burkina Faso into two cohorts: an incident cohort in which new infections were followed after parasite clearance (n=48), and a chronic cohort in which asymptomatic infections were identified and followed (n=60). Parasite kinetics were assessed daily with repeated mosquito feeding assays to quantify transmission potential. All participants were treated upon detection of symptoms; 92% (44/48) of the incident cohort developed symptoms within 35 days, compared to 23% (14/60) of the chronic cohort. All individuals with chronic infection became gametocytaemic during follow-up, whereas only 35% (17/48) in the incident cohort produced gametocytes before becoming symptomatic. Parasite multiplication rate (PMR) and the relative abundance of ap2-g and gexp-5 transcripts were positively associated with game...