The complex relationship of exposure to new Plasmodium infections and incidence of clinical malaria in Papua New Guinea

Abstract
Data availability
Article and author information
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Abstract

The molecular force of blood-stage infection (_molFOB) is a quantitative surrogate metric for malaria transmission at population level and for exposure at individual level. Relationships between _molFOB, parasite prevalence and clinical incidence were assessed in a treatment-to-reinfection cohort, where P.vivax (Pv) hypnozoites were eliminated in half the children by primaquine (PQ). Discounting relapses, children acquired equal numbers of new P. falciparum (Pf) and Pv blood-stage infections/year (Pf-_molFOB=0-18, Pv-_molFOB=0-23) resulting in comparable spatial and temporal patterns in incidence and prevalence of infections. Including relapses, Pv-_molFOB increased >3-fold (relative to PQ-treated children) showing greater heterogeneity at individual (Pv-_molFOB=0-36) and village levels. Pf- and Pv-_molFOB were strongly associated with clinical episode risk. Yearly Pf clinical incidence rate (IR=0.28) was higher than for Pv (IR=0.12) despite lower Pf-_molFOB. These relationships between _molFOB, clinical incidence and parasite prevalence reveal a comparable decline in Pf and Pv transmission that is normally hidden by the high burden of Pv relapses.

Data availability

The following data sets were generated

1. Robinson et al.
(2017) Data from: The complex relationship of exposure to new Plasmodium infections and incidence of clinical malaria in Papua New Guinea
Available at Dryad Digital Repository under a CC0 Public Domain Dedication.

https://doi.org/10.5061/dryad.f9154

The following previously published data sets were used

1. Robinson LJ
2. Wampfler R
3. Betuela I
4. Karl S
5. White MT
6. Li Wai Suen CSN
7. Hofmann NE
8. Kiniboro B
9. Waltmann A
10. Brewster J
11. Lorry L
12. Tarongka N
13. Samol L
14. Silkey M
15. Bassat Q
16. Siba PM
17. Schofield L
18. Felger I
19. Mueller I
(2015) Data from: Strategies for understanding and reducing the Plasmodium vivax and Plasmodium ovale hypnozoite reservoir in Papua New Guinean children: a randomised placebo-controlled trial and mathematical model
Available at Dryad Digital Repositary.

http://datadryad.org/resource/doi:10.5061/dryad.m1n03

Article and author information

Author details

Natalie E Hofmann

Swiss Tropical and Public Health Institute, Basel, Switzerland

Competing interests
The authors declare that no competing interests exist.
Stephan Karl

Walter and Eliza Hall Institute of Medical Research, Parkville, Australia

Competing interests
The authors declare that no competing interests exist.
Rahel Wampfler

Swiss Tropical and Public Health Institute, Basel, Switzerland

Competing interests
The authors declare that no competing interests exist.
Benson Kiniboro

Papua New Guinea Institute of Medical Research, Madang and Maprik, Papua New Guinea

Competing interests
The authors declare that no competing interests exist.
Albina Teliki

Papua New Guinea Institute of Medical Research, Madang and Maprik, Papua New Guinea

Competing interests
The authors declare that no competing interests exist.
Jonah Iga

Papua New Guinea Institute of Medical Research, Madang and Maprik, Papua New Guinea

Competing interests
The authors declare that no competing interests exist.
Andreea Waltmann

Walter and Eliza Hall Institute of Medical Research, Parkville, Australia

Competing interests
The authors declare that no competing interests exist.
Inoni Betuela

Papua New Guinea Institute of Medical Research, Madang and Maprik, Papua New Guinea

Competing interests
The authors declare that no competing interests exist.
Ingrid Felger

Swiss Tropical and Public Health Institute, Basel, Switzerland

Competing interests
The authors declare that no competing interests exist.
Leanne J Robinson

Walter and Eliza Hall Institute of Medical Research, Parkville, Australia

For correspondence
robinson@wehi.edu.au

Competing interests
The authors declare that no competing interests exist.

"This ORCID iD identifies the author of this article:" 0000-0001-9903-1023
Ivo Mueller

Walter and Eliza Hall Institute of Medical Research, Parkville, Australia

For correspondence
ivomueller@fastmail.fm

Competing interests
The authors declare that no competing interests exist.

Funding

Swiss National Science Foundation (310030-134889 310030-159580)

Ingrid Felger
Ivo Mueller

National Institute of Allergy and Infectious Diseases (South West Pacific International Centers of Excellence in malaria research U19 AI089686)

Inoni Betuela
Ingrid Felger
Leanne J Robinson
Ivo Mueller

Bill and Melinda Gates Foundation

Inoni Betuela
Ingrid Felger
Leanne J Robinson
Ivo Mueller

National Health and Medical Research Council (Project Grant #1021544)

Inoni Betuela
Ingrid Felger
Leanne J Robinson
Ivo Mueller

Cellex Foundation

Inoni Betuela
Ivo Mueller

National Health and Medical Research Council (Early Career Fellowship #1016443)

Leanne J Robinson

National Health and Medical Research Council (Early Career Fellowship #1052760)

Stephan Karl

National Health and Medical Research Council (Senior Research Fellowship #1043345)

Ivo Mueller

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Ethics

Human subjects: The study received ethical clearance from the PNG IMR Institutional Review Board (0908), the PNG Medical Advisory Committee (09.11), the Ethics Committee of Basel 237/11 and was conducted in full concordance with the Declaration of Helsinki. Written informed consent was obtained from the parents/guardians of all children enrolled in the study.

Copyright

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.