Dramatic declines in seropositivity as determined with crude extracts of Plasmodium falciparum schizonts between 2000 and 2010 in Dielmo and Ndiop, Senegal

Malaria Journal

Research

Michel Matar Faye¹  Adama Tall¹  Vincent Richard¹  Aissatou Toure Balde¹  Babacar Diouf¹  Fode Diop²  Gora Diop²  Cheikh Sokhna³  Nafissatou Diagne³  Jean-François Trape³ 

[1] Institut Pasteur de Dakar, Avenue Pasteur, Dakar, Senegal;Institut Pasteur de Dakar, Avenue Pasteur, Dakar, Senegal;Université Cheikh Anta Diop de Dakar, Fann, Dakar, Senegal;Institut de Recherche et de Développement, Dakar, Sénégal;

关键词: Malaria;    Plasmodium falciparum;    Seroepidemiology;    IgG;    Schizont crude extract;    Senegal;    Dielmo;    Ndiop;   

DOI  :  10.1186/1475-2875-13-83

 received in 2013-11-08, accepted in 2014-02-26,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundProgrammes of pre-elimination of malaria have been implemented in Senegal since 2010, and the burden of malaria has decreased substantially. These changes in the epidemiology should be monitored with effective tools that allow changes in patterns of transmission to be estimated. In Dielmo and Ndiop, two villages of Senegal with different malaria endemicity, infections have been followed longitudinally for 20 years, during which time there have been several control interventions leading to substantial decreases of transmission. This study aimed to compare malaria antibody responses of the inhabitants of these two villages, between 2000 and 2010, using schizont crude extracts of a local strain of P. falciparum (Pf Sch 07/03).MethodsSera collected from inhabitants of the two villages (141 from Dielmo and 79 from Ndiop in 2000; 143 from Dielmo and 79 from Ndiop in 2010) were used to assess the prevalence of antibodies against crude schizont extracts of Pf Sch 07/03. Three ages groups were defined: [5-9] yrs, [10-14] yrs and [15-19] yrs. Statistical comparisons were performed. Seroprevalence and the magnitude of antibody responses were compared between age groups, villages and periods.ResultsOverall seroprevalence to P.fSch07/03 decreased between 2000 and 2010 in both villages: from 94.4% to 44.4% in Dielmo and from 74.4% to 34.6% in Ndiop. The difference between Dielmo and Ndiop was highly significant in 2000 (p < 0.001) but not in 2010 (p >0.20). The decrease in seroprevalence was larger in younger (more than 40%) than older (less than 19%) inhabitants. Longitudinal monitoring of the younger group showed that seroprevalence decreased between 2000 and 2010 in Dielmo from 98.7 to 79.3, but not in Ndiop from 67.6 to 66.7. The magnitude of antibody responses in seropositive individuals was significantly higher in 2000 than 2010 for both villages.ConclusionsCrude extracts of P. falciparum are appropriate tools for evaluating malaria prevalence at different periods, and in both low and high endemic area. Using crude extracts from local strains to assess transmission may allow efficient evaluation of the consequences of control programs on malaria transmission.

【 授权许可】

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© Diop et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.