Force of infection is key to understanding the epidemiology of Plasmodium falciparum malaria in Papua New Guinean children
- Author(s)
- Mueller, I; Schoepflin, S; Smith, TA; Benton, KL; Bretscher, MT; Lin, E; Kiniboro, B; Zimmerman, PA; Speed, TP; Siba, P; Felger, I;
- Details
- Publication Year 2012-06-19,Volume 109,Issue #25,Page 10030-10035
- Journal Title
- PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
- Publication Type
- Journal Article
- Abstract
- Genotyping Plasmodium falciparum parasites in longitudinal studies provides a robust approach to estimating force of infection (FOI) in the presence of superinfections. The molecular parameter molFOI, defined as the number of new P. falciparum clones acquired over time, describes basic malaria epidemiology and is suitable for measuring outcomes of interventions. This study was designed to test whether molFOI influenced the risk of clinical malaria episodes and how far molFOI reflected environmental determinants of transmission, such as seasonality and small-scale geographical variation or effects of insecticide-treated nets (ITNs). Two hundred sixty-four children 1-3 y of age from Papua New Guinea were followed over 16 mo. Individual parasite clones were tracked longitudinally by genotyping. On average, children acquired 5.9 (SD 9.6) new P. falciparum infections per child per y. molFOI showed a pronounced seasonality, was strongly reduced in children using ITNs (incidence rate ratio, 0.49; 95% confidence interval, [0.38, 0.61]), increased with age, and significantly varied within villages (P = 0.001). The acquisition of new parasite clones was the major factor determining the risk of clinical illness (incidence rate ratio, 2.12; 95% confidence interval, [1.93, 2.31]). Adjusting for individual differences in molFOI completely explained spatial variation, age trends, and the effect of ITN use. This study highlights the suitability of molFOI as a measure of individual exposure and its central role in malaria epidemiology. It has substantial advantages over entomological measures in studies of transmission patterns, and could be used in analyses of host variation in susceptibility, in field efficacy trials of novel interventions or vaccines, and for evaluating intervention effects.
- Publisher
- NATL ACAD SCIENCES
- Keywords
- ENTOMOLOGIC INOCULATION RATES; TANZANIAN CHILDREN; PARASITE POPULATIONS; AFRICAN CHILDREN; WESTERN KENYA; ENDEMIC AREA; TRANSMISSION; DETECTABILITY; VACCINE; TRIAL
- Research Division(s)
- Infection And Immunity; Bioinformatics
- Link To PubMed Central Version
- http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3382533/
- Publisher's Version
- https://doi.org/10.1073/pnas.1200841109
- Terms of Use/Rights Notice
- Copyright © 2013 National Academy of Sciences.
Creation Date: 2012-06-19 12:00:00