Plasmodium vivax and Plasmodium falciparum infection dynamics: re-infections, recrudescences and relapses
Plasmodium vivax and Plasmodium falciparum infection dynamics: re-infections, recrudescences and relapses
Blog Article
Abstract Background In malaria endemic populations, complex patterns of Plasmodium vivax and Plasmodium falciparum blood-stage infection dynamics may be observed.Genotyping samples from longitudinal cohort studies for merozoite surface protein (msp) variants increases the information available in the data, allowing multiple infecting parasite clones in a single individual to be identified.msp genotyped samples from two longitudinal cohorts in Papua New Guinea (PNG) and Thailand were analysed using a statistical model where the times of acquisition and clearance of each clone in every individual were estimated using a process of data augmentation.
Results For the populations analysed, the duration of blood-stage P.falciparum infection was estimated as 36 (95% Credible Interval (CrI): 29, 44) days in PNG, and 135 (95% CrI 94, 191) days in Thailand.Experiments on simulated data indicated that it strikketøy oppbevaring was not possible to accurately estimate the duration of redken shades eq 07m driftwood blood-stage P.
vivax infections due to the lack of identifiability between a single blood-stage infection and multiple, sequential blood-stage infections caused by relapses.Despite this limitation, the method and data point towards short duration of blood-stage P.vivax infection with a lower bound of 24 days in PNG, and 29 days in Thailand.
On an individual level, P.vivax recurrences cannot be definitively classified into re-infections, recrudescences or relapses, but a probabilistic relapse phenotype can be assigned to each P.vivax sample, allowing investigation of the association between epidemiological covariates and the incidence of relapses.
Conclusion The statistical model developed here provides a useful new tool for in-depth analysis of malaria data from longitudinal cohort studies, and future application to data sets with multi-locus genotyping will allow more detailed investigation of infection dynamics.