First malaria infections in a cohort of infants in Benin: biological, environmental and genetic determinants. Description of the study site, population methods and preliminary results
- Agnès Le Port1,2,
- Gilles Cottrell2,3,
- Yves Martin-Prevel4,
- Florence Migot-Nabias1,2,
- Michel Cot1,2,
- André Garcia1,2
- 1Institut de Recherche pour le Développement (IRD), UMR216, Mère et Enfant Face aux Infections Tropicales, Paris, France
- 2Faculté de Pharmacie, Université Paris Descartes, Paris, France
- 3Institut de Recherche pour le Développement (IRD), UMR216, Mère et Enfant Face aux Infections Tropicales, Cotonou, Benin
- 4IRD, UMR204 IRD/Montpellier1/Montpellier2/SupAgro, Prévention des Malnutritions et des Pathologies Associées (NUTRIPASS), Montpellier, France
- Correspondence to Agnès Le Port;
- Received 24 August 2011
- Accepted 6 February 2012
- Published 8 March 2012
Objectives Malaria infection of the placenta during pregnancy was found to be associated with infant susceptibility to malaria. Other factors such as the intensity of malaria transmission and the nutritional status of the child might also play a role, which has not been adequately taken into account in previous studies. The aim of this study was to assess precisely the parts played by environmental, nutritional and biological determinants in first malaria infections, with a special interest in the role of placental infection. The objective of this paper is not to present final results but to outline the rationale of the study, to describe the methods used and to report baseline data.
Design A cohort of infants followed with a parasitological (symptomatic and asymptomatic parasitaemia) and nutritional follow-up from birth to 18 months. Ecological, entomological and behavioural data were collected along the duration of the study.
Setting A rural area in Benin with two seasonal peaks in malaria transmission.
Participants 656 infants of women willing to participate in the study, giving birth in one of the three maternity clinics and living in one of the nine villages of the study area.
Primary Outcome Measures The time and frequency of first malaria parasitaemias in infants, according to Plasmodium falciparum infection of the placenta.
Results 11% of mothers had a malaria-infected placenta at delivery. Mosquito catches made every 6 weeks in the area showed an average annual P falciparum entomological inoculation rate of 15.5, with important time and space variations depending on villages. Similarly, the distribution of rainfalls, maximal during the two rainy seasons, was heterogeneous over the area.
Conclusions Considering the multidisciplinary approach of all factors potentially influencing the malaria status of newborn babies, this study should bring evidence on the implication of placental malaria in the occurrence of first malaria infections in infants.
To cite: Le Port A, Cottrell G, Martin-Prevel Y, et al. First malaria infections in a cohort of infants in Benin: biological, environmental and genetic determinants. Description of the study site, population, methods and preliminary results. BMJ Open 2012;2:e000342. doi:10.1136/bmjopen-2011-000342
Contributors ALP and GC supervised the study in the field. AG and MC planned the study and AG was the coordinator of the study. YMP supervised nutritional data collection, FMN supervised biological data collection. ALP, YMP, GC, FMN, AG and MC participated in the interpretation of findings and wrote the paper.
Funding Funding for this study was received from Agence Nationale de la Recherche (ANR); Ministère de la Recherche et des Technologies, France; Fondation de France; Fondation Mérieux.
Competing interests None.
Ethics approval The protocol was approved by both the Ethical Committee of the Faculté des Sciences de la Santé (FSS) in Benin and the IRD Consultative Committee on Professional Conduct and Ethics (CCDE).
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement Environmental data presented in the article will be available by request to Dr André Garcia ( ).
This is an open-access article distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited, the use is non commercial and is otherwise in compliance with the license. See: http://creativecommons.org/licenses/by-nc/2.0/ and http://creativecommons.org/licenses/by-nc/2.0/legalcode.