This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow E-mail this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ASM journals
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Bejon, P.
Right arrow Articles by Marsh, K.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bejon, P.
Right arrow Articles by Marsh, K.

 Previous Article  |  Next Article 

Infection and Immunity, May 2009, p. 1917-1923, Vol. 77, No. 5
0019-9567/09/$08.00+0     doi:10.1128/IAI.01358-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.

Analysis of Immunity to Febrile Malaria in Children That Distinguishes Immunity from Lack of Exposure{triangledown} ,{dagger}

Philip Bejon,1,2* George Warimwe,1 Claire L. Mackintosh,1 Margaret J. Mackinnon,1 Sam M. Kinyanjui,1 Jennifer N. Musyoki,1 Peter C. Bull,1 and Kevin Marsh1,2

Kenyan Medical Research Institute (KEMRI), Centre for Geographic Medicine Research (Coast), P.O. Box 230, Kilifi 80108, Kenya,1 Nuffield Department of Medicine, Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford, Churchill Hospital, Oxford, United Kingdom2

Received 6 November 2008/ Accepted 6 February 2009

In studies of immunity to malaria, the absence of febrile malaria is commonly considered evidence of "protection." However, apparent "protection" may be due to a lack of exposure to infective mosquito bites or due to immunity. We studied a cohort that was given curative antimalarials before monitoring began and documented newly acquired asymptomatic parasitemia and febrile malaria episodes during 3 months of surveillance. With increasing age, there was a shift away from febrile malaria to acquiring asymptomatic parasitemia, with no change in the overall incidence of infection. Antibodies to the infected red cell surface were associated with acquiring asymptomatic infection rather than febrile malaria or remaining uninfected. Bed net use was associated with remaining uninfected rather than acquiring asymptomatic infection or febrile malaria. These observations suggest that most uninfected children were unexposed rather than "immune." Had they been immune, we would have expected the proportion of uninfected children to rise with age and that the uninfected children would have been distinguished from children with febrile malaria by the protective antibody response. We show that removing the less exposed children from conventional analyses clarifies the effects of immunity, transmission intensity, bed nets, and age. Observational studies and vaccine trials will have increased power if they differentiate between unexposed and immune children.

* Corresponding author. Mailing address: Wellcome Trust/KEMRI Collaborative Programme, P.O. Box 230, Kilife 80108, Kenya. Phone: 254-41-522-063. Fax: 254-41-522-390. E-mail: pbejon{at}kilifi.kemri-wellcome.org

{triangledown} Published ahead of print on 17 February 2009.

{dagger} This paper is published with the permission of the director of KEMRI.

Editor: W. A. Petri, Jr.

Infection and Immunity, May 2009, p. 1917-1923, Vol. 77, No. 5
0019-9567/09/$08.00+0     doi:10.1128/IAI.01358-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Warimwe, G. M., Keane, T. M., Fegan, G., Musyoki, J. N., Newton, C. R. J. C., Pain, A., Berriman, M., Marsh, K., Bull, P. C. (2009). Plasmodium falciparum var gene expression is modified by host immunity. Proc. Natl. Acad. Sci. USA 106: 21801-21806 [Abstract] [Full Text]  


Copyright © 2010 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»