Reduction in the proportion of fevers associated with Plasmodium falciparum parasitaemia in Africa: a systematic review

Abstract Background Malaria is almost invariably ranked as the leading cause of morbidity and mortality in Africa. There is growing evidence of a decline in malaria transmission, morbidity and mortality over the last decades, especially so in East Africa. However, there is still doubt whether this d...

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Bibliographic Details
Published in:Malaria Journal
Main Authors: D'Acremont Valérie, Lengeler Christian, Genton Blaise
Format: Article in Journal/Newspaper
Language:English
Published: BMC 2010
Subjects:
Online Access:https://doi.org/10.1186/1475-2875-9-240
https://doaj.org/article/d760c7a9bfbe487788f6b46442714284
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Summary:Abstract Background Malaria is almost invariably ranked as the leading cause of morbidity and mortality in Africa. There is growing evidence of a decline in malaria transmission, morbidity and mortality over the last decades, especially so in East Africa. However, there is still doubt whether this decline is reflected in a reduction of the proportion of malaria among fevers. The objective of this systematic review was to estimate the change in the Proportion of Fevers associated with Plasmodium falciparum parasitaemia (PFPf) over the past 20 years in sub-Saharan Africa. Methods Search strategy . In December 2009, publications from the National Library of Medicine database were searched using the combination of 16 MeSH terms. Selection criteria . Inclusion criteria: studies 1) conducted in sub-Saharan Africa, 2) patients presenting with a syndrome of 'presumptive malaria', 3) numerators (number of parasitologically confirmed cases) and denominators (total number of presumptive malaria cases) available, 4) good quality microscopy. Data collection and analysis . The following variables were extracted: parasite presence/absence, total number of patients, age group, year, season, country and setting, clinical inclusion criteria. To assess the dynamic of PFPf over time, the median PFPf was compared between studies published in the years ≤2000 and > 2000. Results 39 studies conducted between 1986 and 2007 in 16 different African countries were included in the final analysis. When comparing data up to year 2000 (24 studies) with those afterwards (15 studies), there was a clear reduction in the median PFPf from 44% (IQR 31-58%; range 7-81%) to 22% (IQR 13-33%; range 2-77%). This dramatic decline is likely to reflect a true change since stratified analyses including explanatory variables were performed and median PFPfs were always lower after 2000 compared to before. Conclusions There was a considerable reduction of the proportion of malaria among fevers over time in Africa. This decline provides evidence for the ...