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 gametocyte production. Antibody responses were
higher and PMR lower in chronic infections. The presence of symptoms and
sexual stage immune responses were associated with reductions in
gametocyte infectivity to mosquitoes. We observed that most incident
infections required treatment before the density of mature gametocytes was
sufficient to infect mosquitoes. In contrast, chronic, asymptomatic
infections represented a significant source of mosquito infections. Our
observations support the notion that malaria transmission reduction may be
expedited by enhanced case management, involving both symptom-screening
and infection detection. Clean datasets with molecular data, mosquito feeding assays and
serology data. Data are provided as xls with in second tab the variable
labels