scholarly journals Molecular malaria surveillance using a novel protocol for extraction and analysis of nucleic acids retained on used rapid diagnostic tests

2020 ◽  
Author(s):  
Etienne A. Guirou ◽  
Tobias Schindler ◽  
Salome Hosch ◽  
Olivier Tresor Donfack ◽  
Charlene Aya Yoboue ◽  
...  
Keyword(s):  
Nucleic Acids ◽  
Diagnostic Tests ◽  
Large Scale ◽  
Rapid Diagnostic Tests ◽  
Nucleic Acid Amplification ◽  
Nucleotide Polymorphisms ◽  
Sample Collection ◽  
Malaria Surveillance ◽  
Bioko Island ◽  
Asymptomatic Patients

AbstractThe use of malaria rapid diagnostic tests (RDTs) as a source for nucleic acids that can be analyzed via nucleic acid amplification techniques has several advantages, including minimal amounts of blood, sample collection, simplified storage and shipping conditions at room temperature. We have systematically developed and extensively evaluated a procedure to extract total nucleic acids from used malaria RDTs. The co-extraction of DNA and RNA molecules from small volumes of dried blood retained on the RDTs allows detection and quantification of P. falciparum parasites from asymptomatic patients with parasite densities as low as 1 Pf/µL blood using reverse transcription quantitative PCR. Based on the extraction protocol we have developed the ENAR (Extraction of Nucleic Acids from RDTs) approach; a complete workflow for large-scale molecular malaria surveillance. Using RDTs collected during a malaria indicator survey we demonstrated that ENAR provides a powerful tool to analyze nucleic acids from thousands of RDTs in a standardized and high-throughput manner. We found several, known and new, non-synonymous single nucleotide polymorphisms in the propeller region of the kelch 13 gene among isolates circulating on Bioko Island, Equatorial Guinea.

scholarly journals Analysis of nucleic acids extracted from rapid diagnostic tests reveals a significant proportion of false positive test results associated with recent malaria treatment

2021 ◽  
Author(s):  
Salome Hosch ◽  
Charlene Aya Yoboue ◽  
Olivier Tresor Donfack ◽  
Etienne A Guirou ◽  
Jean-Pierre Dangy ◽  
...  
Keyword(s):  
Quality Control ◽  
Nucleic Acids ◽  
False Positive ◽  
Diagnostic Tests ◽  
False Negative ◽  
Rapid Diagnostic Tests ◽  
Malaria Treatment ◽  
Malaria Surveillance ◽  
Bioko Island ◽  
Surveillance Programs

Surveillance programs often use malaria rapid diagnostic tests (RDTs) to determine the proportion of the population carrying parasites in their peripheral blood to assess the malaria transmission intensity. Despite an increasing number of reports on false-negative and false-positive RDT results, there is a lack of systematic quality control activities for RDTs deployed in malaria surveillance programs. Our study provides a larger scale comparative evaluation of RDTs used in the 2018 Malaria Indicator Survey (MIS) conducted on Bioko Island, Equatorial Guinea. We conducted a molecular analysis by extraction of nucleic acids from 1,800 negative and 1,065 positive RDTs followed by qPCR analysis. These results were combined with a dataset collected in a comprehensive questionnaire from each MIS participant. Of the 2,865 RDTs that were collected in 2018 on Bioko Island and analysed in our study, 4.7% had a false-negative result. These false-negative RDT results were associated with low parasite density infections. In a substantial proportion of samples, we identified masked pfhrp2 and pfhrp3 gene deletions in which at least one P. falciparum strain carried a gene deletion. Among all positive RDTs analysed, 28.4% were tested negative by qPCR and therefore considered to be false-positive. Analysing the questionnaire data collected from the participants, this high proportion of false-positive RDT results could be explained by PfHRP2 antigen persistence after recent malaria treatment. We conclude that malaria surveillance depending solely on RDTs needs well-integrated quality control procedures assessing the extend and impact of reduced sensitivity and specificity of RDTs on malaria control programs.

scholarly journals Plasmodium falciparum Allelic Diversity: A Comparison of DNA Extraction from Isolates Collected on Rapid Diagnostic Tests (Rdts) and Filter Paper

2021 ◽  
Author(s):  
Denise Patricia Mawili-Mboumba ◽  
Marie Louise Tshibola Mbuyi ◽  
Noe Patrick M’bondoukwe ◽  
Marielle Karine Bouyou-Akotet
Keyword(s):  
Plasmodium Falciparum ◽  
Nucleic Acids ◽  
Filter Paper ◽  
Diagnostic Tests ◽  
Allelic Diversity ◽  
Storage Conditions ◽  
Rapid Diagnostic Tests ◽  
Sample Collection ◽  
Filter Papers

Background: To perform molecular epidemiologic studies based on large cohorts, material such as RDTs or filter papers are useful for biological sample collection and extraction of RNA or DNA of good quality. Thus, we aimed to assess the quality of DNA extracted from malaria rapid diagnostic tests (RDTs) stored at various temperatures for the analysis of Plasmodium falciparum genetic diversity. Methods: Febrile patients benefitted from free malaria diagnosis using microscopy in a malaria sentinel site, at the Regional Hospital Estuaire-Melen, in Gabon, in 2015. P. falciparum isolates were collected onto one filter paper and 2 similar RDTs devices (Acon®) per patient. Nucleic acids were extracted with QiAmp Qiagen kit from paper and RDTs and the quality of the DNA was analyzed by msp1 gene amplification. Results: Msp1gene amplification was achieved in nucleic acids extracted from all filter papers and RDTs devices (n = 45, 100%). K1 alleles were detected in 93.3% (n = 42/45) of the samples and Mad20 alleles in 73.3% (n = 33/45). The number and the intensity of K1 and/or Mad20 fragments were comparable according to the sample collection material and the storage conditions (room temperature vs -20°C) of the samples. The size of the fragments indicating allelic diversity was comparable in 80% (n=36) of the samples. Conclusion: These data show that RDTs are a valuable source of DNA for malaria parasite genetic polymorphism analysis. Storage conditions of the devices did not influence the quality of DNA extracted from RDTs device, although some alleles may be missed.

scholarly journals Molecular malaria surveillance using a novel protocol for extraction and analysis of nucleic acids retained on used rapid diagnostic tests

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Etienne A. Guirou ◽  
Tobias Schindler ◽  
Salome Hosch ◽  
Olivier Tresor Donfack ◽  
Charlene Aya Yoboue ◽  
...  
Keyword(s):  
Nucleic Acids ◽  
Diagnostic Tests ◽  
Rapid Diagnostic Tests ◽  
Malaria Surveillance

scholarly journals Potential for community based surveillance of febrile diseases: Feasibility of self-administered rapid diagnostic tests in Iquitos, Peru and Phnom Penh, Cambodia

2021 ◽  
Vol 15 (4) ◽  
pp. e0009307
Author(s):  
Amy C. Morrison ◽  
Julia Schwarz ◽  
Jennie L. Mckenney ◽  
Jhonny Cordova ◽  
Jennifer E. Rios ◽  
...  
Keyword(s):  
Infectious Diseases ◽  
Disease Transmission ◽  
Diagnostic Tests ◽  
Large Scale ◽  
Health Workers ◽  
Rapid Diagnostic Tests ◽  
Community Members ◽  
Phnom Penh ◽  
Local Public Health ◽  
At Home

Rapid diagnostic tests (RDTs) have the potential to identify infectious diseases quickly, minimize disease transmission, and could complement and improve surveillance and control of infectious and vector-borne diseases during outbreaks. The U.S. Defense Threat Reduction Agency’s Joint Science and Technology Office (DTRA-JSTO) program set out to develop novel point-of-need RDTs for infectious diseases and deploy them for home use with no training. The aim of this formative study was to address two questions: 1) could community members in Iquitos, Peru and Phnom Penh, Cambodia competently use RDTs of different levels of complexity at home with visually based instructions provided, and 2) if an RDT were provided at no cost, would it be used at home if family members displayed febrile symptoms? Test kits with written and video (Peru only) instructions were provided to community members (Peru [n = 202]; Cambodia [n = 50]) or community health workers (Cambodia [n = 45]), and trained observers evaluated the competency level for each of the several steps required to successfully operate one of two multiplex RDTs on themselves or other consenting participant (i.e., family member). In Iquitos, >80% of residents were able to perform 11/12 steps and 7/15 steps for the two- and five-pathogen test, respectively. Competency in Phnom Penh never reached 80% for any of the 12 or 15 steps for either test; the percentage of participants able to perform a step ranged from 26–76% and 23–72%, for the two- and five-pathogen tests, respectively. Commercially available NS1 dengue rapid tests were distributed, at no cost, to households with confirmed exposure to dengue or Zika virus; of 14 febrile cases reported, six used the provided RDT. Our findings support the need for further implementation research on the appropriate level of instructions or training needed for diverse devices in different settings, as well as how to best integrate RDTs into existing local public health and disease surveillance programs at a large scale.

Performance of rapid diagnostic tests for HCV infection in serum or plasma

2021 ◽  
Author(s):  
Stéphane Chevaliez ◽  
Françoise Roudot-Thoraval ◽  
Christophe Hézode ◽  
Jean-Michel Pawlotsky ◽  
Richard Njouom
Keyword(s):  
Hepatitis C ◽  
Diagnostic Tests ◽  
Large Scale ◽  
Low Cost ◽  
Antibody Test ◽  
Cost Effective ◽  
Rapid Diagnostic Tests ◽  
Treatment Programs ◽  
Clinical Sensitivity ◽  
Cost Treatment

Aim: HCV diagnosis will become the bottleneck in eliminating hepatitis C. Simple, accurate and cost-effective testing strategies are urgently needed to improve hepatitis C screening and diagnosis. Materials & methods: Performance of seven rapid diagnostic tests (RDT) have been assessed in a large series (n = 498) of serum or plasma specimens collected in France and in Cameroon. Results: Specificity varied from 96.1 to 100%. The clinical sensitivity, compared with immunoassays as the reference, was high for all seven RDT (97.2–100%). The Multisure HCV antibody assay and OraQuick HCV rapid antibody test reached sensitivity ≥99%. Conclusion: A number of RDT may be suitable for WHO prequalification and may be implemented in the framework of large-scale low-cost treatment programs to achieve the WHO viral hepatitis objectives by 2030.

LABORATORY METHODS AND PREVALENCE OF SARS-COV-2 INFECTIONS IN THE 2ND SEMESTER OF 2021 IN THE EMERGENCY CLINICAL COUNTY HOSPITAL OF CONSTANTA

2021 ◽  
Author(s):  
Stoicescu Ramona ◽  
Stoicescu Razvan-Alexandru ◽  
Codrin Gheorghe ◽  
Schroder Verginica
Keyword(s):  
Respiratory Tract ◽  
Diagnostic Tests ◽  
Rapid Diagnostic Tests ◽  
Antigen Detection ◽  
Nucleic Acid Amplification ◽  
Rt Pcr ◽  
Laboratory Methods ◽  
Rapid Tests ◽  
Polymerase Chain ◽  
Tract Infections

"Diagnosing infections with SARS-CoV-2 is still of great interest due to the health and economic impact of COVID pandemic. The 4th wave of the COVID-19 pandemic is expected and is considered to be stronger and faster due to the dominance of Delta variant which is highly contagious [1]. SARS-CoV-2 also known as 2019-nCoV is one of the three coronaviruses (together with SARS-CoV or SARS-CoV1/Severe acute respiratory syndrome coronavirus), MERS-CoV /Middle East Respiratory Syndrome coronavirus) which can cause severe respiratory tract infections in humans [2]. Early diagnosis in COVID 19 infection is the key for preventing infection transmission in collectivity and proper medical care for the ill patients. Gold standard for diagnosing SARS-Co-V-2 infection according to WHO recommendation is using nucleic acid amplification tests (NAAT)/ reverse transcription polymerase chain reaction (RT-PCR). The search is on to develop reliable but less expensive and faster diagnostic tests that detect antigens specific for SARS-CoV-2 infection. Antigen-detection diagnostic tests are designed to directly detect SARSCoV-2 proteins produced by replicating virus in respiratory secretions so-called rapid diagnostic tests, or RDTs. The diagnostic development landscape is dynamic, with nearly a hundred companies developing or manufacturing rapid tests for SARS-CoV-2 antigen detection [3]. In the last 3 months our hospital introduced the antigen test or Rapid diagnostic tests (RDT) which detects the presence of viral proteins (antigens) expressed by the COVID-19 virus in a sample from the respiratory tract of a person. All RDT were confirmed next day with a RT-PCR. The number of positive cases detected during 3 months in our laboratory was 425. There were 326 positive tests in April, 106 positive tests in May and 7 positive tests in June. Compared with the number of positive tests in the 1st semester of 2021, the positive tests have significantly declined."

scholarly journals Point-of-Care Diagnostic Tests for Detecting SARS-CoV-2 Antibodies: A Systematic Review and Meta-Analysis of Real-World Data

2020 ◽  
Vol 9 (5) ◽  
pp. 1515 ◽  
Author(s):  
Matteo Riccò ◽  
Pietro Ferraro ◽  
Giovanni Gualerzi ◽  
Silvia Ranzieri ◽  
Brandon Michael Henry ◽  
...  
Keyword(s):  
Systematic Review ◽  
Diagnostic Tests ◽  
Large Scale ◽  
Point Of Care ◽  
Meta Analysis ◽  
Rapid Diagnostic Tests ◽  
Diagnostic Methods ◽  
Rt Pcr ◽  
Real World Data ◽  
Healthcare Facilities

SARS-CoV-2 is responsible for a highly contagious infection, known as COVID-19. SARS-CoV-2 was discovered in late December 2019 and, since then, has become a global pandemic. Timely and accurate COVID-19 laboratory testing is an essential step in the management of the COVID-19 outbreak. To date, assays based on the reverse-transcription polymerase chain reaction (RT-PCR) in respiratory samples are the gold standard for COVID-19 diagnosis. Unfortunately, RT-PCR has several practical limitations. Consequently, alternative diagnostic methods are urgently required, both for alleviating the pressure on laboratories and healthcare facilities and for expanding testing capacity to enable large-scale screening and ensure a timely therapeutic intervention. To date, few studies have been conducted concerning the potential utilization of rapid testing for COVID-19, with some conflicting results. Therefore, the present systematic review and meta-analysis was undertaken to explore the feasibility of rapid diagnostic tests in the management of the COVID-19 outbreak. Based on ten studies, we computed a pooled sensitivity of 64.8% (95%CI 54.5–74.0), and specificity of 98.0% (95%CI 95.8–99.0), with high heterogeneity and risk of reporting bias. We can conclude that: (1) rapid diagnostic tests for COVID-19 are necessary, but should be adequately sensitive and specific; (2) few studies have been carried out to date; (3) the studies included are characterized by low numbers and low sample power, and (4) in light of these results, the use of available tests is currently questionable for clinical purposes and cannot substitute other more reliable molecular tests, such as assays based on RT-PCR.

scholarly journals Performance of the BinaxNOW COVID-19 Antigen Rapid Diagnostic Test for the Detection of SARS-CoV-2

2021 ◽  
Author(s):  
Fernando A Ocampo Gonzalez ◽  
Nicholas M Moore
Keyword(s):  
Nucleic Acid ◽  
Diagnostic Tests ◽  
Healthcare Workers ◽  
Turnaround Time ◽  
Rapid Diagnostic Tests ◽  
Nucleic Acid Amplification ◽  
Substantial Agreement ◽  
Cycle Number ◽  
Percent Agreement ◽  
Κ Statistic

Abstract Background: Diagnosis of COVID-19 disease primarily relies on nucleic acid amplification tests (NAAT) that amplify and detect viral RNA in specimens. These methods are expensive and time consuming. Antigen-based rapid diagnostic tests can substantially decrease turnaround time.Methods: We analyzed paired anterior nares swabs collected from symptomatic patients and asymptomatic healthcare workers being tested COVID-19. One swab was used for a direct RDT and the results were compared to NAAT.Results: 89 paired specimens were evaluated. The positive percent agreement (PPA) for the antigen RDT was 68.2%, and the negative percent agreement (NPA) was 98.5%. Despite a low PPA, the Κ statistic was 0.733 indicating substantial agreement with the NAAT result. The median cycle number in paired specimens with concordant results was significantly lower than in discordant specimens (21.3 versus 32.3; P=0.003).Conclusions: The RDT showed modest PPA and high NPA when compared to NAAT. The quick TAT and use of an inexpensive test more frequently could be useful in settings in which results from NAAT testing is delayed.

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