Urban Malaria in Dakar, Senegal: Chemosusceptibility and Genetic Diversity of Plasmodium Falciparum Isolates

Abstract

The chemosusceptibility and genetic polymorphism of Plasmodium falciparum populations from 48 patients hospitalized for malaria at the Hospital Principal in Dakar, Senegal were investigated during the 2002 malaria transmission season. Sixty-two percent of the isolates collected were from patients with severe malaria and 38% were from patients with mild malaria. In vitro activities of chloroquine, quinine, cycloguanil, atovaquone, mefloquine, halofantrine, and artesunate were evaluated. The prevalence of mutations in the Plasmodium falciparum dihydrofolate reductase (dhfr) and dihyropteroate synthetase (dhps) genes and the P. falciparum chloroquine resistance transporter (Pfcrt) gene associated with cycloguanil, pyrimethamine, sulfadoxine, and chloroquine resistance were estimated. The genetic polymorphism of the parasite populations was evaluated by analysis of the highly polymorphic regions of merozoite surface protein 1 (msp1) block 2 and msp2. Seventy percent of the isolates were assessed by an in vitro assay. Fifty-two percent of the isolates were chloroquine resistant, 45% were cycloguanil resistant, and 24% were atovaquone resistant. Four percent had low susceptibility to quinine. The Pfcrt and dhfr mutations were associated with in vitro chloroquine- and antimetabolic drug-resistant isolates, respectively. Approximately 70% of the isolates contained two or more clones. Genetic diversity of P. falciparum was high. The prevalence of allelic family K1 of msp1 was 68%. Isolates of P. falciparum were highly resistant to chloroquine, cycloguanil and atovaquone. The transmission rate of malaria in Dakar is low but a high degree of genetic polymorphism can increase severe malaria, as shown by persons coming to Dakar from areas highly endemic for malaria. Areas with urban malaria should use vector control measures and efficient chemoprophylaxis for non-immune populations.

Genetic Diversity of Plasmodium falciparum Strains in Children under Five Years of Age in Southeastern Tanzania~!2009-10-12~!2010-01-12~!2010-05-05~!

“…This may have an implication on treatment of malaria among children living in endemic areas where immunity is stable and drug resistance issues are to be considered. These findings corroborate with those from Dakar, Senegal [20] and Mlimba, Tanzania [21], which reported 3D7 alleles to be more prevalent than FC27 in those infected with single, double and triple infections. Nevertheless, different proportions of the two allelic families in Ulanga observed in this study corroborate with the findings obtained in Dielmo, Senegal [22,23] and Sao Tome [24].…”

Platinum(II) and palladium(II) complexes with (N,N′) and (C,N,N′)− ligands derived from pyrazole as anticancer and antimalarial agents: Synthesis, characterization and in vitro activities

“…All strains were synchronized twice with sorbitol before use. Clonality was verified using PCR genotyping of polymorphic genetic markers, msp1, msp2 and microsatellite loci [55,56].…”

Immunomodulatory effects of recombinant BCG expressing MSP-1C ofPlasmodium falciparumon LPS- or LPS+IFN-γ-stimulated J774A.1 cells

“…1,2 Various intervention and eradication programs have been implemented by the World Health Organization (WHO) and non-governmental organizations (NGOs), but the prevalence of malaria is increasing, especially in young children. This problem might be due to various possible contributing factors such as genetic diversity, 3,4 the emergence of multidrug-resistant strains 2,[5][6][7] and environmental factors, including climate change. 8,9 Knowledge regarding the mechanisms by which malaria parasites are eliminated by the host immune system is still not fully understand and sometimes controversial.…”