Analysis of false-negative rapid diagnostic tests for symptomatic malaria in the Democratic Republic of the Congo DOI Creative Commons
Jonathan B. Parr,

Eddy Kieto,

Fernandine Phanzu

et al.

Scientific Reports, Journal Year: 2021, Volume and Issue: 11(1)

Published: March 22, 2021

The majority of Plasmodium falciparum malaria diagnoses in Africa are made using rapid diagnostic tests (RDTs) that detect histidine-rich protein 2. Increasing reports false-negative RDT results due to parasites with deletions the pfhrp2 and/or pfhrp3 genes (pfhrp2/3) raise concern about existing strategies. We previously identified pfhrp2-negative among asymptomatic children Democratic Republic Congo (DRC), but their impact on diagnosis symptomatic is unknown. performed a cross-sectional study RDTs subjects 2017. Parasites were characterized by microscopy; RDT; pfhrp2/3 genotyping and species-specific PCR assays; bead-based immunoassay for antigens; whole-genome sequencing. Among 3627 subjects, 427 (11.8%) had RDT-/microscopy + results. from eight (0.2%) samples initially classified as putative PCR, antigen testing sequencing confirmed presence intact genes. 56.8% PCR-confirmed malaria. Non-falciparum co-infection P. was common (13.2%). Agreement between HRP2-based satisfactory (Cohen's kappa = 0.66) superior microscopy (0.33). Symptomatic pfhrp2/3-deleted not observed. Ongoing use appropriate detection DRC.

Language: Английский

Temporal and spatial analysis of Plasmodium falciparum genomics reveals patterns of parasite connectivity in a low-transmission district in Southern Province, Zambia DOI Creative Commons
Abebe A. Fola, Kara A. Moser, Özkan Aydemir

et al.

Malaria Journal, Journal Year: 2023, Volume and Issue: 22(1)

Published: July 7, 2023

Abstract Background Understanding temporal and spatial dynamics of malaria transmission will help to inform effective interventions strategies in regions approaching elimination. Parasite genomics are increasingly used monitor epidemiologic trends, including assessing residual across seasons importation into these regions. Methods In a low seasonal setting southern Zambia, total 441 Plasmodium falciparum samples collected from 8 neighbouring health centres between 2012 2018 were genotyped using molecular inversion probes (MIPs n = 1793) targeting 1832 neutral geographically informative SNPs distributed the parasite genome. After filtering for quality missingness, 302 1410 retained downstream population genomic analyses. Results The analyses revealed most (67%, 202) infections harboured one clone (monogenomic) with some variation at local level suggesting low, but heterogenous transmission. Relatedness identity-by-descent (IBD) analysis variable distribution IBD segments genome 6% pairs highly-related (IBD ≥ 0.25). Some populations persisted multiple seasons, that persistence this low-transmission region is fueled by parasites “seeding” dry season. For recent years, clusters clonal identified dissimilar general population, fragmented small scales due intensified control efforts. Clustering PCA t-SNE showed lack substantial structure. Conclusion Leveraging both epidemiological data provided comprehensive picture fluctuations pre-elimination Zambia over 7 years.

Language: Английский

Citations

16
Comparison of molecular surveillance methods to assess changes in the population genetics of Plasmodium falciparum in high transmission DOI Creative Commons
Anita Ghansah, Kathryn E. Tiedje, Dionne C. Argyropoulos

et al.

Frontiers in Parasitology, Journal Year: 2023, Volume and Issue: 2

Published: April 3, 2023

A major motivation for developing molecular methods malaria surveillance is to measure the impact of control interventions on population genetics Plasmodium falciparum as a potential marker progress towards elimination. Here we assess three established (i) single nucleotide polymorphism (SNP) barcoding (panel 24-biallelic loci), (ii) microsatellite genotyping 12-multiallelic and (iii) varcoding (fingerprinting var gene diversity, akin microhaplotyping) identify changes in parasite response short-term indoor residual spraying (IRS) intervention. Typical high seasonal transmission Africa, multiclonal infections were found 82.3% (median 3; range 1-18) 57.8% 2; 1-12) asymptomatic individuals pre- post-IRS, respectively, Bongo District, Ghana. Since directly phasing multilocus haplotypes genetic analysis not possible biallelic SNPs microsatellites, chose ~200 low-complexity biased double clone analysis. Each method presented different pattern change diversity structure consequence variability usable data relative markers (i.e., < microsatellites var). Varcoding showed overall failure IRS intervention significantly from pre-IRS characteristics many diverse genomes low similarity). The 24-SNP barcode provided limited information analysis, largely due nature leading proportion double-allele calls view more isolate relatedness compared varcoding. Relative performance, suitability, cost-effectiveness relevant sample size local elimination high-transmission endemic areas are discussed.

Language: Английский

Citations

14
Population genomic evidence of structured and connected Plasmodium vivax populations under host selection in Latin America DOI Creative Commons
Johanna Helena Kattenberg, Pieter Monsieurs, Julie De Meyer

et al.

Ecology and Evolution, Journal Year: 2024, Volume and Issue: 14(3)

Published: March 1, 2024

Abstract Pathogen genomic epidemiology has the potential to provide a deep understanding of population dynamics, facilitating strategic planning interventions, monitoring their impact, and enabling timely responses, thereby supporting control elimination efforts parasitic tropical diseases. Plasmodium vivax , responsible for most malaria cases outside Africa, shows high genetic diversity at level, driven by factors like sub‐patent infections, hidden reservoir hypnozoites, early transmission mosquitoes. While Latin America made significant progress in controlling falciparum it faces challenges with residual P. . To characterize structure we have analyzed largest collection genomes date, including 1474 high‐quality from 31 countries across Asia, Oceania, America. globally, American isolates form distinctive population, which is further divided into sub‐populations occasional clonal pockets. Genetic within continent was associated intensity transmission. Population differentiation exists between Central North Coast South America, vs. Amazon Basin, gene flow but limited connectivity Northwest Basin. Shared regions these parasite populations indicate adaptive evolution, particularly genes related DNA replication, RNA processing, invasion, motility – crucial parasite's survival diverse environments. Understanding population‐level adaptations effective efforts, offering insights mechanisms behind drug resistance, immune evasion, dynamics.

Language: Английский

Citations

6
Two decades of molecular surveillance in Senegal reveal rapid changes in known drug resistance mutations over time DOI Creative Commons
Yaye Dié Ndiaye, Wesley Wong, Julie Thwing

et al.

Malaria Journal, Journal Year: 2024, Volume and Issue: 23(1)

Published: July 9, 2024

Abstract Background Drug resistance in Plasmodium falciparum is a major threat to malaria control efforts. Pathogen genomic surveillance could be invaluable for monitoring current and emerging parasite drug resistance. Methods Data from two decades (2000–2020) of continuous molecular P. parasites Senegal were retrospectively examined assess historical changes mutations. Several known markers their surrounding haplotypes profiled using combination single nucleotide polymorphism (SNP) whole genome sequence based population genomics. Results This dataset was used track temporal whose timing correspond historically significant events such as the withdrawal chloroquine (CQ) introduction sulfadoxine-pyrimethamine (SP) 2003. Changes mutation frequency at Pfcrt K76T Pfdhps A437G coinciding with 2014 seasonal chemoprevention (SMC) observed. In 2014, increased while declined. Haplotype-based analyses showed that this rapid increase due recent selective sweep started after 2014. Discussion (Conclusion) The troubling sign amodiaquine (AQ) Senegal. Emerging AQ may threaten future clinical efficacy artesunate-amodiaquine (ASAQ) AQ-dependent SMC chemoprevention. These results highlight potential detecting populations stress need monitor effectiveness partner artemisinin-based therapy (ACT)

Language: Английский

Citations

5
Analysis of false-negative rapid diagnostic tests for symptomatic malaria in the Democratic Republic of the Congo DOI Creative Commons
Jonathan B. Parr,

Eddy Kieto,

Fernandine Phanzu

et al.

Scientific Reports, Journal Year: 2021, Volume and Issue: 11(1)

Published: March 22, 2021

The majority of Plasmodium falciparum malaria diagnoses in Africa are made using rapid diagnostic tests (RDTs) that detect histidine-rich protein 2. Increasing reports false-negative RDT results due to parasites with deletions the pfhrp2 and/or pfhrp3 genes (pfhrp2/3) raise concern about existing strategies. We previously identified pfhrp2-negative among asymptomatic children Democratic Republic Congo (DRC), but their impact on diagnosis symptomatic is unknown. performed a cross-sectional study RDTs subjects 2017. Parasites were characterized by microscopy; RDT; pfhrp2/3 genotyping and species-specific PCR assays; bead-based immunoassay for antigens; whole-genome sequencing. Among 3627 subjects, 427 (11.8%) had RDT-/microscopy + results. from eight (0.2%) samples initially classified as putative PCR, antigen testing sequencing confirmed presence intact genes. 56.8% PCR-confirmed malaria. Non-falciparum co-infection P. was common (13.2%). Agreement between HRP2-based satisfactory (Cohen's kappa = 0.66) superior microscopy (0.33). Symptomatic pfhrp2/3-deleted not observed. Ongoing use appropriate detection DRC.

Language: Английский

Citations

32