scholarly journals Analysis of false-negative rapid diagnostic tests for symptomatic malaria in the Democratic Republic of the Congo

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jonathan B. Parr ◽  
Eddy Kieto ◽  
Fernandine Phanzu ◽  
Paul Mansiangi ◽  
Kashamuka Mwandagalirwa ◽  
...  
Keyword(s):  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Diagnostic Tests ◽  
Democratic Republic ◽  
False Negative ◽  
Rapid Diagnostic Tests ◽  
Whole Genome ◽  
Symptomatic Malaria ◽  
Asymptomatic Children ◽  
Republic Of The Congo

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

scholarly journals Causes of false-negative rapid diagnostic tests for symptomatic malaria in the DRC

2020 ◽  
Author(s):  
Jonathan B Parr ◽  
Eddy Kieto ◽  
Fernandine Phanzu ◽  
Paul Masiangi ◽  
Kashamuka Mwandagalirwa ◽  
...  
Keyword(s):  
Whole Genome Sequencing ◽  
Falciparum Malaria ◽  
Genome Sequencing ◽  
Diagnostic Tests ◽  
False Negative ◽  
Rapid Diagnostic Tests ◽  
Whole Genome ◽  
Cross Sectional ◽  
Symptomatic Malaria ◽  
Asymptomatic Children

Background The majority of Plasmodium falciparum malaria diagnoses in Africa are made using rapid diagnostic tests (RDTs) that detect histidine-rich protein 2. Increasing reports of false-negative RDT results due to parasites with deletions of the pfhrp2 and/or pfhrp3 genes (pfhrp2/3) raise concern about existing malaria diagnostic strategies. We previously identified pfhrp2-negative parasites among asymptomatic children in the Democratic Republic of the Congo (DRC), but their impact on diagnosis of symptomatic malaria is unknown. Methods We performed a cross-sectional study of false-negative RDTs in symptomatic subjects in 2017. Parasites were characterized by microscopy; RDT; pfhrp2/3 genotyping and species-specific PCR assays; a multiplex bead-based immunoassay; and/or whole-genome sequencing. Results Among 3,627 symptomatic subjects, we identified 427 (11.8%) RDT-/microscopy+ cases. Parasites from eight (0.2%) samples were initially classified as putative pfhrp2/3 deletions by PCR, but antigen testing and whole-genome sequencing confirmed the presence of intact genes. Malaria prevalence was high (57%) and non-falciparum co-infection common (15%). HRP2-based RDT performance was satisfactory and superior to microscopy. Conclusions Symptomatic malaria due to pfhrp2/3-deleted P. falciparum was not observed in the DRC. Ongoing HRP2-based RDT use is appropriate for the detection of falciparum malaria in the DRC.

scholarly journals Prevalence of Plasmodium falciparum isolates lacking the histidine rich protein 2 gene among symptomatic malaria patients in Kwilu Province of the Democratic Republic of Congo

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Yannick Bazitama Munyeku ◽  
Alain Abera Musaka ◽  
Medard Ernest ◽  
Chris Smith ◽  
Paul Mankadi Mansiangi ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Diagnostic Tests ◽  
Gene Deletion ◽  
Democratic Republic ◽  
Democratic Republic Of Congo ◽  
False Negative ◽  
Rapid Diagnostic Tests ◽  
Republic Of Congo ◽  
Gene Deletions ◽  
Symptomatic Malaria

Abstract Background Malaria rapid diagnostic tests have become a primary and critical tool for malaria diagnosis in malaria-endemic countries where Plasmodium falciparum Histidine Rich Protein 2-based rapid diagnostic tests (PfHRP2-based RDTs) are widely used. However, in the last decade, the accuracy of PfHRP2-based RDTs has been challenged by the emergence of P. falciparum strains harbouring deletions of the P. falciparum histidine rich protein 2 (pfhrp2) gene, resulting in false-negative results. In the Democratic Republic of Congo (D.R. Congo), little is known about the prevalence of the pfhrp2 gene deletion among P. falciparum isolates infecting symptomatic patients, especially in low to moderate transmission areas where pfhrp2 deletion parasites are assumed to emerge and spread. Here we determine the local prevalence and factors associated with pfhrp2 gene deletions among symptomatic malaria patients in the Kwilu Province of the D.R. Congo. Methods We used secondary data from a prospective health facility-based cross-sectional study conducted in 2018. Blood was collected for microscopy, PfHRP2-RDT, and spotted onto Whatman filter paper for downstream genetic analysis. Genomic DNA was extracted and used to perform PCR assays for the detection and confirmation of pfhrp2 gene deletions. Fischer’s exact and the Kruskal–Wallis tests were applied to look for associations between potential explanatory variables and the pfhrp2 gene deletion with a level of statistical significance set at P < 0.05. Results Of the 684 enrolled symptomatic patients, 391 (57.7%) were female. The majority (87.7%) reported the presence of mosquito breeding sites within the household’s compound, and fever was the most reported symptom (81.6%). The overall prevalence of the pfhrp2 gene deletion was 9.2% (95% CI: 6.7%–12.1%). The deletion of the pfhrp2 gene was associated with health zone of origin (P = 0.012) and age (P = 0.019). Among false-negative PfHRP2-RDT results, only 9.9% were due to pfhrp2 gene deletion. Conclusions P. falciparum isolates with pfhrp2 gene deletions are relatively common among symptomatic patients in Kwilu province. Further investigations are needed to provide enough evidence for policy change. Meanwhile, the use of RDTs targeting PfHRP2 and parasite lactate dehydrogenase (pLDH) antigens could limit the spread of deleted isolates. Graphic Abstract

scholarly journals 531. Practical and Evidence-Based Considerations for Implementation of Bacterial Whole-Genome Sequencing Within Longitudinal Infection Control Practice

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S255-S255
Author(s):  
Donald S Chen ◽  
Moira Quinn ◽  
Rita M Sussner ◽  
Guiqing Wang ◽  
John T Fallon ◽  
...  
Keyword(s):  
Infection Control ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Tertiary Care ◽  
False Negative ◽  
Lessons Learned ◽  
Evidence Based ◽  
Guidance Document ◽  
Whole Genome ◽  
Care Hospital

Abstract Background Whole-genome sequencing (WGS) of bacteria is becoming a routine tool within microbiology, yet its utility to help guide infection control (IC) practice longitudinally is underexplored. As with any technology adopted in the hospital, the integration of WGS into IC practice must be carefully managed and considered. We qualitatively report an evidence-based implementation workflow that considers WGS to help proactively guide IC professionals during investigation of infectious outbreaks. Methods We built upon lessons learned in an ongoing surveillance effort at a tertiary care hospital—utilizing retrospective WGS data within the Philips IntelliSpace Epidemiology system—to understand facilitators and barriers to the use of bacterial WGS longitudinally to inform IC workflow. Our team established a 9-month workgroup to study the practical aspects of implementing WGS in routine IC practice. From expert opinion collected via the workgroup, in addition to evidence from the literature, a workflow guidance document and checklist were codified. New ideas included incorporating education to promote the establishment of an IC triage process. Results Facilitators to implementation included ability to display genomic relatedness alongside relevant patient data to enable clinical actionability, ability to pivot time and resources rapidly when infections are a pseudo outbreak (false positive) or missed outbreak (false negative), opportunities for nuanced staff education, and willingness to be a first-of-kind adopter. Barriers were communication of genomic concepts to IC professionals and relevant institutional stakeholders, maintaining sharable notes of active investigations to promote data-sharing practices, and timing and review of relevant interventions into the facility workflow. Strategies to address these issues are considered. Conclusion This study provides a novel framework for adaptation of existing IC workflow strategies to leverage the utility of bacterial WGS, and it presents a schema to effectively engage relevant stakeholders, based on an analysis of the unique challenges inherent within IC practice. It also offers an innovative model for the development and implementation of IC workflows to account for, and adapt to, site-specific conditions. Disclosures All authors: No reported disclosures.

scholarly journals Clinical Evaluation of QuickNaviTM-Ebola in the 2018 Outbreak of Ebola Virus Disease in the Democratic Republic of the Congo

Viruses ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 589 ◽  
Author(s):  
Sheila Makiala ◽  
Daniel Mukadi ◽  
Anja De Weggheleire ◽  
Shino Muramatsu ◽  
Daisuke Kato ◽  
...  
Keyword(s):  
West Africa ◽  
Diagnostic Tests ◽  
Ebola Virus ◽  
Democratic Republic ◽  
Virus Disease ◽  
Point Of Care ◽  
Rapid Diagnostic Tests ◽  
Ebola Virus Disease ◽  
Blood Samples ◽  
Republic Of The Congo

The recent large outbreaks of Ebola virus disease (EVD) in West Africa and the Democratic Republic of the Congo (DRC) have highlighted the need for rapid diagnostic tests to control this disease. In this study, we clinically evaluated a previously developed immunochromatography-based kit, QuickNaviTM-Ebola. During the 2018 outbreaks in DRC, 928 blood samples from EVD-suspected cases were tested with QuickNaviTM-Ebola and the WHO-approved GeneXpert. The sensitivity and specificity of QuickNaviTM-Ebola, estimated by comparing it to GeneXpert-confirmed cases, were 85% (68/80) and 99.8% (846/848), respectively. These results indicate the practical reliability of QuickNaviTM-Ebola for point-of-care diagnosis of EVD.

OzFoodNet into the future: the rapid evolution of foodborne disease surveillance in Australia

2017 ◽  
Vol 38 (4) ◽  
pp. 179
Author(s):  
Ben Polkinghorne ◽  
Anthony Draper ◽  
Michelle Harlock ◽  
Robyn Leader
Keyword(s):  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Diagnostic Tests ◽  
Disease Surveillance ◽  
Rapid Evolution ◽  
Enteric Pathogens ◽  
Whole Genome ◽  
Foodborne Disease ◽  
Surveillance Network ◽  
Culture Independent

OzFoodNet is Australia's national enhanced foodborne disease surveillance network. OzFoodNet is currently evolving in order to meet the most significant challenges faced since it commenced in 2000: the transition to culture independent diagnostic tests and the introduction of whole genome sequencing for typing of enteric pathogens. This has changed the nature of foodborne disease surveillance and outbreak investigation in Australia.

scholarly journals Field accuracy of HIV rapid diagnostic tests for blood donors screening, Bukavu, Eastern Democratic Republic of the Congo

2018 ◽  
Vol 12 (06) ◽  
pp. 471-476
Author(s):  
Théophile Mitima Kashosi ◽  
Céléstin Bisangamo Kyambikwa ◽  
Philémon Mbarabara Mulongo ◽  
Jean Bisimwa Nachega
Keyword(s):  
Diagnostic Tests ◽  
Blood Donors ◽  
Democratic Republic ◽  
Point Of Care ◽  
Kappa Statistic ◽  
Rapid Diagnostic Tests ◽  
Cohen’S Kappa ◽  
Cohen's Kappa ◽  
Republic Of The Congo ◽  
Hiv 1

Introduction: Rapid diagnostic tests (RDTs) are widely used for point-of-care. point-of-care diagnosis of HIV infection in resource-limited settings. However, there are no data about their field diagnostic performance in Eastern Democratic Republic of the Congo (DRC), especially in the context of blood banks screening for transfusion safety purpose. Methodology: Blood specimens were collected from blood donors in Bukavu, Eastern DRC, from May the 1st to June the 30th, 2015, to evaluate the accuracy of Alere Determine HIV-1/2, Trinity Biotech Uni‑Gold HIV, and DoubleCheckGold Ultra HIV 1& 2 compared to the laboratory-based 4th generation ELISA apDia HIV Ag/Ab assay. Sensitivity, specificity, positive and negative predictive values, and related 95% confidence intervals were calculated using MedCalc statistical software version 15.1. Reliability was evaluated using Cohen’s Kappa Statistic, κ. Results: Among 312 participants who provided blood bags, 96/312 (30.7%) were female and the mean age (SD) was 31.7 years (± 8.1years). Sensitivity for the three tests was 57.1% (95% CI: 18.4-90.1). The specificity was 99.7% (95% CI: 18.4-90.1) for Alere Determine HIV 1/2, 100% (95% CI: 98.8-100.0) for Uni-Gold HIV, and (100% (95% CI: 98.8-100.0) for DoubleCheckGold Ultra HIV 1&2. Cohen’s Kappa Statistic showed moderate agreement between the 4th generation ELISA apDia HIV Ag/Ab and RDTs Alere Determine HIV 1/2 and Uni-Gold HIV (κ = 0.66; 95% CI: 0.55- 0.76) but good agreement for DoubleCheckGold Ultra HIV1&2 (κ = 0.72; 95% CI: 0.61 – 0.82). Conclusions: Compared to the laboratory-based ELISA apDia HIV Ag/Ab assay, the currently used 3rd generation HIV RDTs showed poor field accuracy results in a context of blood donors screening. These data support the need for 4th generation Ag-Ab RDTs in transfusion blood qualification.

Clinical utility of whole genome sequencing in hematological neoplasms.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 7028-7028
Author(s):  
Jesus Gutierrez-Abril ◽  
Daniel Leongamornlert ◽  
Yangyu Zhou ◽  
SooWah Lee ◽  
Max Levine ◽  
...  
Keyword(s):  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Clinical Utility ◽  
Lymphoblastic Leukemia ◽  
False Negative ◽  
Control Sample ◽  
Leukemic Cells ◽  
Training Dataset ◽  
Whole Genome ◽  
Hematological Neoplasms

7028 Background: Hematological neoplasms are often characterized by acute onset and rapid disease progression. Cytogenetics, FISH, SNP arrays, targeted DNA and RNA sequencing are performed to inform diagnosis, risk stratification and guide treatment decisions. Whole genome sequencing (WGS) offers the opportunity to comprehensively characterize all putative biomarkers in a single assay. However, a limitation in current WGS implementation is the requirement for a germline sample, as sources of control tissue are frequently contaminated with leukemic cells resulting in false negative calls. Methods: To evaluate the clinical utility and feasibility of WGS in the diagnostic work up of leukemias, we analyzed 57 B-cell acute lymphoblastic leukemia (B-ALL) from the UKALL14 trial (NCT01085617) with no informative biomarkers at diagnosis. WGS analysis was performed on the leukemic sample and a matching control sample (with minimal residual disease level of <1%). Using this dataset, we trained the development of an unmatched (uWGS) analytical workflow (Isabl) for a tumor only WGS study. This workflow was validated across 20 hematologic neoplasms (12 B-ALL, 6 AML and 2 T-ALL). Results: Among the 57 cases, 5 failed QC owing to low tumor content (<25%). Of the remaining 52, putative biomarkers of clinical relevance were identified by WGS in 69% (36/52). These included delineation of aberrant karyotypes where conventional chromosome banding failed (4/52), the detection of newly described fusion genes (such as IGH-DUX4 and EP300-ZNF384 in 21/52) and recurrent gene mutations (i.e. PAX5 P80R, ZEB2 H1038R in 11/52). uWGS workflow in our training dataset captured 86% of biomarkers identified in the matched analysis (3/3 ploidy, 21/22 fusion and 7/11 coding). Concordance between the matched and uWGS workflow for arm-level and focal copy number alterations (CNAs), structural variants (SVs) and annotated hotspot mutations were 94%, 84%, 83% and 100% respectively. Independent validation of the uWGS workflow across 20 myeloid and lymphoid neoplasms, recapitulated all clinically reported biomarkers (14/15 CNAs, 16/16 SVs) as well as captured two novel findings not previously detected in two B-ALL patients, to include a focal deletion in BTG1 and the fusion gene P2RY8-CRLF2, as well as a NOTCH1 translocation in T-ALL. Conclusions: Our findings demonstrate that comprehensive WGS allows for the detection of the same biomarkers as a range of clinical assays using a single test, as well as the opportunity to discover novel clinical and research findings to support future correlative research and biomarker development. Additionally, we developed and validated an uWGS workflow that allows WGS analysis of hematopoietic neoplasms at diagnosis, enabling detection and reporting of clinically relevant biomarkers.

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