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We here analyze data from the first year of an ongoing nationwide program of genetic surveillance of Plasmodium falciparum parasites in Senegal. The analysis is based on 1097 samples collected at health facilities during passive malaria case detection in 2019; it provides a baseline for analyzing parasite genetic metrics as they vary over time and geographic space. The study's goal was to identify genetic metrics that were informative about transmission intensity and other aspects of transmission dynamics, focusing on measures of genetic relatedness between parasites. We found the best genetic proxy for local malaria incidence to be the proportion of polygenomic infections (those with multiple genetically distinct parasites), although this relationship broke down at low incidence. The proportion of related parasites was less correlated with incidence while local genetic diversity was uninformative. The type of relatedness could discriminate local transmission patterns: two nearby areas had similarly high fractions of relatives, but one was dominated by clones and the other by outcrossed relatives. Throughout Senegal, 58% of related parasites belonged to a single network of relatives, within which parasites were enriched for shared haplotypes at known and suspected drug resistance loci and at one novel locus, reflective of ongoing selection pressure. Senegal has initiated a national sentinel surveillance program for malaria parasite genetics. Here, the authors report data from the first year of the program and use it to investigate local malaria incidence, patterns of transmission, and genetic loci under selection. [ABSTRACT FROM AUTHOR]

In 2006, Senegal adopted artemisinin-based combination therapy (ACT) as first-line treatment in the management of uncomplicated malaria. This study aimed to update the status of antimalarial efficacy more than ten years after their first introduction. This was a randomized, three-arm, open-label study to evaluate the efficacy and safety of artemether-lumefantrine (AL), artesunate-amodiaquine (ASAQ) and dihydroartemisinin-piperaquine (DP) in Senegal. Malaria suspected patients were screened, enrolled, treated, and followed for 28 days for AL and ASAQ arms or 42 days for DP arm. Clinical and parasitological responses were assessed following antimalarial treatment. Genotyping (msp1, msp2 and 24 SNP-based barcode) were done to differentiate recrudescence from re-infection; in case of PCR-confirmed treatment failure, Pfk13 propeller and Pfcoronin genes were sequenced. Data was entered and analyzed using the WHO Excel-based application. A total of 496 patients were enrolled. In Diourbel, PCR non-corrected/corrected adequate clinical and parasitological responses (ACPR) was 100.0% in both the AL and ASAQ arms. In Kedougou, PCR corrected ACPR values were 98.8%, 100% and 97.6% in AL, ASAQ and DP arms respectively. No Pfk13 or Pfcoronin mutations associated with artemisinin resistance were found. This study showed that AL, ASAQ and DP remain efficacious and well-tolerated in the treatment of uncomplicated P. falciparum malaria in Senegal. [ABSTRACT FROM AUTHOR]

Isothermal nucleic acid amplification assays such as the loop mediated isothermal amplification (LAMP), are well suited for field use as they do not require thermal cyclers to amplify the DNA. To further facilitate the use of LAMP assays in remote settings, simpler sample preparation methods and lyophilized reagents are required. The performance of a commercial malaria LAMP assay (Illumigene Malaria LAMP) was evaluated using two sample preparation workflows (simple filtration prep (SFP)) and gravity-driven filtration prep (GFP)) and pre-dispensed lyophilized reagents. Laboratory and clinical samples were tested in a field laboratory in Senegal and the results independently confirmed in a reference laboratory in the U.S.A. The Illumigene Malaria LAMP assay was easily implemented in the clinical laboratory and gave similar results to a real-time PCR reference test with limits of detection of ≤2.0 parasites/μl depending on the sample preparation method used. This assay reliably detected Plasmodium sp. parasites in a simple low-tech format, providing a much needed alternative to the more complex molecular tests for malaria diagnosis. [ABSTRACT FROM AUTHOR]