A High Force of Plasmodium vivax Blood-Stage Infection Drives the Rapid Acquisition of Immunity in Papua New Guinean Children

Koepfli, C; Colborn, KL; Kiniboro, B; Lin, E; Speed, TP; Siba, PM; Felger, I; Mueller, I

Author(s): Koepfli, C; Colborn, KL; Kiniboro, B; Lin, E; Speed, TP; Siba, PM; Felger, I; Mueller, I;
Details: Publication Year 2013-09,Volume 7,Issue #9,Page e2403
Journal Title: PLOS NEGLECTED TROPICAL DISEASES
Publication Type: Journal Article
Abstract: Background: When both parasite species are co-endemic, Plasmodium vivax incidence peaks in younger children compared to P. falciparum. To identify differences in the number of blood stage infections of these species and its potential link to acquisition of immunity, we have estimated the molecular force of blood-stage infection of P. vivax (molFOB, i.e. the number of genetically distinct blood-stage infections over time), and compared it to previously reported values for P. falciparum. Methods: P. vivax molFOB was estimated by high resolution genotyping parasites in samples collected over 16 months in a cohort of 264 Papua New Guinean children living in an area highly endemic for P. falciparum and P. vivax. In this cohort, P. vivax episodes decreased three-fold over the age range of 1-4.5 years. Results: On average, children acquired 14.0 new P. vivax blood-stage clones/child/year-at-risk. While the incidence of clinical P. vivax illness was strongly associated with molFOB (incidence rate ratio (IRR) = 1.99, 95% confidence interval (CI95) [1.80, 2.19]), molFOB did not change with age. The incidence of P. vivax showed a faster decrease with age in children with high (IRR = 0.49, CI95 [0.38, 0.64] p < 0.001) compared to those with low exposure (IRR = 0.63, CI95[0.43, 0.93] p = 0.02). Conclusion: P. vivax molFOB is considerably higher than P. falciparum molFOB (5.5 clones/child/year-at-risk). The high number of P. vivax clones that infect children in early childhood contribute to the rapid acquisition of immunity against clinical P. vivax malaria.
Publisher: PUBLIC LIBRARY SCIENCE
Keywords: DUFFY BINDING-PROTEIN; ANTIBODY-RESPONSES; FALCIPARUM-MALARIA; ACQUIRED-IMMUNITY; P. VIVAX; PATTERNS; PROTECTION; DISEASE; ANTIGEN; TRANSMISSION
Research Division(s): Bioinformatics; Infection And Immunity
Publisher's Version: https://doi.org/10.1371/journal.pntd.0002403
Open Access at Publisher's Site: http://www.plosntds.org/article/info%3Adoi%2F10.1371%2Fjournal.pntd.0002403
Terms of Use/Rights Notice: Copyright: © 2013 Koepfli et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Documents: journal.pntd.0002403.pdf - (0.56MB, application/pdf)

Creation Date: 2013-09-01 12:00:00