Distribution of Plasmodium falciparum gametocytes and malaria-attributable fraction of fever episodes along an altitudinal transect in Western Cameroon

Malaria Journal

Research

Laura Guidone¹  Christophe Antonio-Nkondjio²  Herman-Parfait Awono-Ambene²  Frédéric Simard³  Mbida Mpoame⁴  Bridget Nyih-Kong⁴  François Fopa⁵  Timoléon Tchuinkam⁶ 

[1] Hôpital Saint Vincent De Paul, Mission Catholique Sacré Cœur, BP 011, Dschang, Cameroon;Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), BP 288, Yaoundé, Cameroun;Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), BP 288, Yaoundé, Cameroun;MIVEGEC, UMR IRD224-CNRS5290-UM, Institut de Recherche pour le Développement, BP 64501, 911 Avenue Agropolis, Montpellier, France;Malaria Research Unit of the Laboratory of Applied Biology and Ecology (MRU-LABEA), Department of Animal Biology, Faculty of Sciences of the University of Dschang, P. O. Box 067, Dschang, Cameroon;Malaria Research Unit of the Laboratory of Applied Biology and Ecology (MRU-LABEA), Department of Animal Biology, Faculty of Sciences of the University of Dschang, P. O. Box 067, Dschang, Cameroon;Hôpital Saint Vincent De Paul, Mission Catholique Sacré Cœur, BP 011, Dschang, Cameroon;Malaria Research Unit of the Laboratory of Applied Biology and Ecology (MRU-LABEA), Department of Animal Biology, Faculty of Sciences of the University of Dschang, P. O. Box 067, Dschang, Cameroon;Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), BP 288, Yaoundé, Cameroun;

关键词: Highland malaria;    Infectious reservoir;    Fever episode;    Malaria early warning system;    Epidemic;   

DOI  :  10.1186/s12936-015-0594-6

 received in 2014-04-10, accepted in 2015-01-07,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundHighland areas are hypoendemic zones of malaria and are therefore prone to epidemics, due to lack of protective immunity. So far, Cameroon has not succeeded in implementing a convenient and effective method to detect, prevent and forecast malaria epidemic in these peculiar zones. This monitoring and evaluation study aims to assess the operational feasibility of using the human malaria infectious reservoir (HMIR) and the malaria-attributable fraction of fever episodes (MAFE) as indicators, in designing a malaria epidemic early warning system (MEWS).MethodsLongitudinal parasitological surveys were conducted in sentinel health centres installed in three localities, located along an altitudinal transect in Western Cameroon: Santchou (750 m), Dschang (1,400 m) and Djuttitsa (1,965 m). The syndromes of outpatients with malaria-like complaints were recorded and their blood samples examined. The HMIR and the MAFE were estimated and their spatial-temporal variations described.ResultsThe prevalence of asexual Plasmodium infection in outpatients decreased with increasing altitude; meanwhile the HMIR remained fairly constant, indicating that scarcity of malaria disease in highlands is likely due to absence of vectors and not parasites. In lowland, children carried the heaviest malaria burden in the form of febrile episodes, and asexual parasites decreased with age, after an initial peak in the 0-5 year’s age group; however, they were similar for all age groups in highland. The HMIR did not show any variation with age in the plain; but some discrepancies were observed in the highland with extreme age groups, and migration of populations between lowland and highland was suspected to be the cause. Plasmodium infection was perennial in the lowland and seasonal uphill, with malaria disease occurring here mostly during the short dry season. The MAFE was high and did not change with altitude.ConclusionIt is obvious that a malaria outbreak will cause the sudden rise of HMIR and MAFE in highland, prior to the malaria season; the discrepancy with lowland would then help detecting an incipient malaria epidemic. It is recommended that in designing the MEWS, the National Malaria Control Programme should include these parameters and put special emphasis on: altitude, age groups and seasons.

【 授权许可】

CC BY   
© Tchuinkam et al.; licensee BioMed Central. 2015