Abstract:
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Prompt and accurate diagnosis of malaria is part of an effective disease management (1)
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because if not treated malaria can quickly become life-threatening, whereas false
positives increase treatment costs and drug-induced resistance, giving a wrong idea of
therapeutic efficacy. Since the symptoms of malaria are nonspecific, the observation of
clinical features alone might not be enough and should be confirmed with a
parasitological analysis. Microscopic examination of Giemsa-stained thin and/or thick
blood smears remains the conventional approach for diagnosis (2). The sensitivity of this
relatively inexpensive method is excellent, allowing the detection of as few as 5
parasites per µL of blood, and permitting also the determination of the infecting species
and of the developmental stage of circulating parasites. In addition, smears provide a
permanent record for quality assessment of the diagnosis. However, microscopy
requires considerable expertise learned through extended training, the procedure is
labor-intensive and time-consuming, and the variability in stains and in techniques used
to collect and process blood affects slide interpretation (3). Finally, routine clinical
microscopy cannot reliably detect very low parasitemias (<5 parasites/µL) or
sequestered parasites, and mixed infections are often missed, especially when
Plasmodium malariae and Plasmodium ovale are present, as their densities are often
low relative to Plasmodium falciparum ( |