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Plasmodium falciparum increased time in circulation underlies persistent asymptomatic infection in the dry season

ABSTRACT: The dry season is a major challenge for Plasmodium falciparum parasites in many malaria endemic regions, where water availability limits mosquitoes to only part of the year. How P. falciparum bridges two transmission seasons months apart, without being cleared by the host or compromising host survival is poorly understood. Here we show that low levels of P. falciparum parasites persist in the blood of asymptomatic Malian individuals during the 5- to 6-month dry season, rarely causing symptoms and minimally affecting the host immune response. Parasites isolated during the dry season are transcriptionally distinct from those of subjects with febrile malaria in the transmission season, reflecting longer circulation within each replicative cycle, of parasitized erythrocytes without adhering to the vascular endothelium. Low parasite levels during the dry season are not due to impaired replication, but rather increased splenic clearance of longer-circulating infected erythrocytes. We propose that P. falciparum virulence in areas of seasonal malaria transmission is regulated so that the parasite decreases its endothelial binding capacity, allowing increased splenic clearance and enabling several months of subclinical parasite persistence.

ORGANISM(S): Human Homo Sapiens

TISSUE(S): Blood

DISEASE(S): Malaria

SUBMITTER: Manuel Llinas

PROVIDER: ST001384 | MetabolomicsWorkbench | Mon May 25 00:00:00 BST 2020

REPOSITORIES: MetabolomicsWorkbench

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Plasmodium falciparum increased time in circulation underlies persistent asymptomatic infection in the dry season

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