Genetic diversity of Plasmodium falciparum isolates from uncomplicated malaria cases in Ghana over a decade

Abstract

BackgroundGenotyping malaria parasites to assess their diversity in different geographic settings have become necessary for the selection of antigenic epitopes for vaccine development and for antimalarial drug efficacy or resistance investigations. This study describes the genetic diversity of Plasmodium falciparum isolates from uncomplicated malaria cases over a ten year period (2003–2013) in Ghana using the polymorphic antigenic marker, merozoite surface protein 2 (msp2).MethodsArchived filter paper blood blots from children aged nine years and below with uncomplicated malaria collected from nine sites in Ghana were typed for the presence of the markers. A total of 880 samples were genotyped for msp2 for the two major allelic families, FC27 and 3D7, using nested polymerase chain reaction (PCR). The allele frequencies and the multiplicity of infection were determined for the nine sites for five time points over a period of ten years, 2003–2004, 2005–2006, 2007–2008, 2010 and 2012–2013 malaria transmission seasons.ResultsThe number of different alleles detected for the msp2 gene by resolving PCR products on agarose gels was 14. Both of the major allelic families, 3D7 and FC27 were common in all population samples. The highest multiplicity of infection (MOI) was observed in isolates from Begoro (forest zone, rural site): 3.31 for the time point 2007–2008. A significant variation was observed among the sites in the MOIs detected per infection (Fisher's exact test, P < 0.001) for the 2007 isolates and also at each of the three sites with data for three different years, Hohoe, P = 0.03; Navrongo, P < 0.001; Cape Coast, P < 0.001. Overall, there was no significant difference between the MOIs of the three ecological zones over the years (P = 0.37) and between the time points when data from all sites were pooled (P = 0.40).ConclusionsThe diversity and variation between isolates detected using the msp2 gene in Ghanaian isolates were observed to be profound; however, there was homogeneity throughout the three ecological zones studied. This is indicative of gene flow between the parasite populations across the country probably due to human population movements (HPM).Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1692-1) contains supplementary material, which is available to authorized users.

Impact of an Irrigation Dam on the Transmission and Diversity of Plasmodium falciparum in a Seasonal Malaria Transmission Area of Northern Ghana

“…MOI was also found to be significantly higher in the wet season compared with the dry season at the nondam site (p � 0.0002) but not at the dam site (Table 3). ese data agree with the report by Duah et al [33] who found similar MOI in the Savannah regions of Ghana. Although this study did not directly assess the levels of gametocytes and malaria transmission by the vector, there are published reports of a direct correlation between MOI and transmission intensity [35], and the higher dam site MOI could mean a higher extent of transmission at this site during the dry season compared with the nondam site.…”

“…e study showed a moderate-to-high P. falciparum allelic diversity with the 3D7 allelic family being the most predominant variant circulating in the study communities ( Figure 2). is is similar to data reported from other regions of Ghana and countries in sub-Saharan Africa with similar malaria transmission settings [29,[31][32][33]. A study conducted in the south of Benin however reported the FC27 family as the most predominant allelic family [34].…”

Plasmodium falciparum genotype and gametocyte prevalence in children with uncomplicated malaria in coastal Ghana

“…Fertilization between two distinct parasites provides the opportunity for chromosome recombination during meiosis, which enhances genetic diversity in the parasite population. Geometric mean MOIs for msp1 and msp2 of 1.90 and 1.88 were slightly lower than obtained in an earlier report from the middle belt of Ghana where MOI was 2.3 in July/August, [52] but similar to another report of MOI in southern Ghana which was 1.93 [24] and 1.3 in 2013 [53]. This discrepancy may be due to differences in ecological zones [54], malaria transmission intensity [36, 55] and/or the treatment-seeking behaviour of malaria patients within the various population [56, 57].…”

Natural antibody responses to Plasmodium falciparum MSP3 and GLURP(R0) antigens are associated with low parasite densities in malaria patients living in the Central Region of Ghana

“…However, this study identified the 3D7 allele of msp2 as the most prevalent (Fig. 2 ), which was contrary to our previous study [ 28 ] but similar to other studies conducted in Ghana [ 33 , 34 ].…”