The complex relationship of exposure to new <i>Plasmodium</i> infections and incidence of clinical malaria in Papua New Guinea.
prospective_cohort · Level II
Where this comes from
- Record sourced from PubMed, PMID 28862132.
- Also identified by DOI 10.7554/eLife.23708 and PMC identifier 5606846.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The molecular force of blood-stage infection (<sub>mol</sub>FOB) is a quantitative surrogate metric for malaria transmission at population level and for exposure at individual level. Relationships between <sub>mol</sub>FOB, parasite prevalence and clinical incidence were assessed in a treatment-to-reinfection cohort, where <i>P.vivax</i> (<i>Pv</i>) hypnozoites were eliminated in half the children by primaquine (PQ). Discounting relapses, children acquired equal numbers of new <i>P. falciparum</i> (<i>Pf</i>) and <i>Pv</i> blood-stage infections/year (<i>Pf-</i><sub>mol</sub>FOB = 0-18, <i>Pv-</i><sub>mol</sub>FOB = 0-23) resulting in comparable spatial and temporal patterns in incidence and prevalence of infections. Including relapses, <i>Pv-</i><sub>mol</sub>FOB increased >3 fold (relative to PQ-treated children) showing greater heterogeneity at individual (<i>Pv-</i><sub>mol</sub>FOB = 0-36) and village levels. <i>Pf-</i> and <i>Pv-</i><sub>mol</sub>FOB were strongly associated with clinical episode risk. Yearly <i>Pf</i> clinical incidence rate (IR = 0.28) was higher than for <i>Pv</i> (IR = 0.12) despite lower <i>Pf-</i><sub>mol</sub>FOB. These relationships between <sub>mol</sub>FOB, clinical incidence and parasite prevalence reveal a comparable decline in <i>Pf</i> and <i>Pv</i> transmission that is normally hidden by the high burden of <i>Pv</i> relapses. ClinicalTrials.gov NCT02143934.
Medical subject headings
- Environmental Exposure
- Malaria, Falciparum
- Malaria, Vivax