Research
Extensive dynamics of Plasmodium falciparum densities, stages and genotyping profiles
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* Corresponding author: Anna Färnert anna.farnert@ki.se
1 Unit of Infectious Diseases, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, S-17176 Stockholm, Sweden
2 Department of Parasitology, Mycology and Environmental Microbiology, Swedish Institute for Infectious Disease Control, Solna, Sweden
3 Nyamisati Malaria Research, National Institute of Medical Research, Dar es Salaam, Tanzania
Malaria Journal 2008, 7:241 doi:10.1186/1475-2875-7-241
Published: 21 November 2008Abstract
Background
Individuals living in areas of high malaria transmission often have different Plasmodium falciparum clones detected in the peripheral blood over time. The aim of this study was to assess the dynamics of asymptomatic P. falciparum infections in a few hours intervals.
Methods
Capillary blood samples were collected 6-hourly during five days from asymptomatic children in a highly endemic area in Tanzania. Parasite densities and maturation stages were investigated by light microscopy. Types and number of clones were analysed by PCR based genotyping of the polymorphic merozoite surface proteins 1 and 2 genes. Results: Parasite densities and maturation stages fluctuated 48-hourly with a gradual shift into more mature forms. Various genotyping patterns were observed in repeated samples over five days with only few samples with identical profiles. Up to six alleles differed in samples collected six hours apart in the same individual.
Conclusion
This detailed assessment highlights the extensive within-host dynamics of P. falciparum populations and the limitations of single blood samples to determine parasite densities, stages and genotyping profiles in a malaria infected individual.