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Updated: May 9, 2026
Protocol for Plasmodium falciparum Infections in Mosquitoes and Infection Phenotype Determination
Published on: July 3, 2007
Plasmodium falciparum genotype population dynamics in asymptomatic children from Senegal
Sayeh Jafari-Guemouri1, Christian Boudin, Nadine Fievet
1UR 010, Mother and Child Health in the Tropics, Institut de Recherche pour le Développement (IRD), Faculté de Pharmacie, 4, Avenue de l'Observatoire, Paris, France.
Insights
Asymptomatic children in malaria-endemic areas harbor diverse Plasmodium falciparum genotypes. Frequent blood sampling reveals significant daily fluctuations in parasite density and complex, mixed infections, highlighting the need for repeated sampling to understand malaria dynamics.
Area of Science:
- Malariology
- Genetics
- Parasitology
Background:
- Malaria endemic regions often see individuals with mixed Plasmodium falciparum parasite populations.
- Understanding the dynamics of these mixed infections is crucial for effective malaria control.
Purpose of the Study:
- To investigate temporal variations in blood parasite densities and circulating genotypes in asymptomatic Senegalese children.
- To assess the complexity of Plasmodium falciparum infections over short time intervals.
Main Methods:
- Studied 21 asymptomatic Senegalese children with Plasmodium falciparum infections.
- Collected samples eight times over three days, with 4-12 hour intervals.
- Quantified parasite densities using thick blood smears and genotypes via fragment analysis.
Main Results:
- Observed dramatic fluctuations in parasite densities (up to 1:1,000 ratio) with daily peaks.
- Detected polyclonal infections in all children, with 5.2-6.8 genotypes per child.
- Identified distinct behaviors among genotypes, with some fluctuating significantly while others remained stable.
Conclusions:
- A single blood sample does not capture the full complexity of Plasmodium falciparum parasite populations.
- Repeated sampling is essential for a comprehensive understanding of parasite population dynamics and infection complexity.
- Findings emphasize the dynamic nature of asymptomatic malaria infections.
Abstract:
In areas where malaria is endemic, infected individuals generally harbor a mixture of genetically distinct Plasmodium falciparum parasite populations. For the first time, we studied temporal variations of blood parasite densities and circulating genotypes in asymptomatic Senegalese children, at time intervals as short as 4-12 h. Twenty-one Senegalese children, presenting with an asymptomatic P. falciparum infection, were sampled eight times within three days. Parasite density was assessed by thick blood smears, and all infecting genotypes were quantified by the fragment-analysis method. Parasite densities showed dramatic fluctuations up to a 1 to 1,000 ratio, with at least one peak of parasite density. Polyclonal infections were detected in all children, with a multiplicity of infection of 5.2-6.8 genotypes per child. A single sample never reflected the full complexity of the parasite populations hosted by a given individual. Genotypes with different behaviors were detected in all children, some genotypes undergoing major fluctuations, while others were highly stable during the follow-up. A single peripheral blood sampling does not reflect the total parasite load. Repeated sampling is needed to have a more detailed scheme of parasite population dynamics and a better knowledge of the true complexity of an infection.
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