Plasmodium vivax malaria in Mali: a study from three different regions

Abstract

Background: Plasmodium vivax has traditionally been considered virtually absent from Western and Central Africa, due to the absence of the Duffy blood group in most of the population living in these areas. Recent reports, however, suggest the circulation of P. vivax in sub-Saharan Africa.

Methods: Giemsa/Field-stained smears from febrile patients recruited in five different cities (Goundam, Tombouctou, Gao, Bourem and Kidal) pertaining to three regions from Northern Mali were examined. Nested-PCR and DNA sequence analyses of selected samples were performed to fully confirm the presence of P. vivax infections.

Results: Results demonstrated the presence of P. vivax infections in close to 30% of the cases as detected by Giemsa/Field-stained smears and nested-PCR and DNA-sequence analyses of selected samples unequivocally confirmed the presence of P. vivax.

Conclusions: The diagnostics of this human malaria parasite should be taken into account in the context of malaria control and elimination efforts, not only in Mali, but also in sub-Saharan Africa.

Figure 1

Vivax malaria in Mali. Geographical regions where this study was conducted are circled in red. Ménaka, the geographical area where P. vivax was also recently detected [10] is circled in blue. Adaptation from the map produced by NordNordWest [CC-BY-SA-3.0-de (http://creativecommons.org/licenses/by-sa/3.0/de/deed.en)], via Wikimedia Commons.

Figure 2

Plasmodium vivax infections in Northern Mali. A. Giemsa-stained images of samples from different regions. B. Amplified fragments from a nested-PCR assay using P. vivax-specific primers. Molecular weight in base pairs (bp) of predicted amplified size fragments (117 bp) corresponding to P. vivax (arrow) is shown to the left.

Figure 3

Bootstrapped phylogenetic rooted tree constructed by the parsimony method for the SSUr RNA sequences of Plasmodium vivax from Mali. Horizontal branch lengths between nodes correspond to the number of shared derived changes. Slide52-72_clone1-3 represent the slide from Mali were we obtained the gDNA and the number of clone that was sequenced. SlideBrazil, positive P. vivax control. 18S_PVX samples were obtained from PlasmoDB 8.2. Other Plasmodium spp. 18S sequences were obtained from GenBank. Accession Numbers for all of them are listed in Methods.