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

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 policy change from presumptive anti-malarial treatment of all children with fever to laboratory diagnosis and treatment upon result. This should insure appropriate care of non-malaria fevers and rationale use of anti-malarials

Quantifying Biomass Of Secondary Forest After Slash-And-Burn Cultivation In Central Menabe, Madagascar

RAHARIMALALA O, BUTTLER A, SCHLAEPFER R & GOBAT J-M. 2012. Quantifying biomass of secondary forest after slash-and-burn cultivation in Central Menabe, Madagascar. Biomass is the principal input of nutrients in slash-and-burn cultivation of tropical dry deciduous forest. In this paper, we report the aboveground biomass of ligneous and herbaceous vegetation as a function of the age of abandonment after cultivation in order to analyse the potential amount of nutrients released into the soil. To estimate the biomass of trees, we used dendrometric classes based on height and circumference at breast height of all individual plants inventoried in the plots in four growth types. For biomass measures, we harvested representative trees in each defined class. The quantity of total biomass increased with age of abandonment, reaching 72 t ha(-1) after 40 years of abandonment. The species that contributed most to biomass were Fernandoa madagascariensis, Diospyros perrieri, Dalbergia sp., Poupartia silvatica, Tarenna sericea, Xeromphis sp., Phylloctenium decaryanum, Stereospermum euphorioides and Croton greveanum. Diospyros increased regularly already after 10 years of abandonment. The biomass of Dalbergia also increased with the age of abandonment, but after 30 years, this quantity decreased because of selective harvest by farmers. Fernandoa increased after 30 years, as did Poupartia, but the latter became a key player as it was, comparatively, the species with the highest biomass shortly after 30 years of abandonment