scholarly journals DIAGNOSIS OF MALARIA INFECTION WITH OR WITHOUT DISEASE

2012 ◽  
Vol 4 (1) ◽  
pp. e2012036 ◽  
Author(s):  
Zeno Bisoffi ◽  
Federico Gobbi ◽  
Dora Buonfrate ◽  
Jef Van den Ende
Keyword(s):  
Diagnostic Tests ◽  
Malaria Infection ◽  
Cost Effective ◽  
Clinical Malaria ◽  
Rapid Diagnostic Tests ◽  
The Other ◽  
Adults And Children ◽  
Fever Management ◽  
Positive Results ◽  
Very High

The revised W.H.O. guidelines for malaria management in endemic countries recommend that treatment should be reserved to laboratory confirmed cases, both for adults and children. Currently the most widely used tools are rapid diagnostic tests (RDTs), that are accurate and reliable in diagnosing malaria infection. However, an infection is not necessarily a clinical malaria, and RDTs may give positive results in febrile patients who have another cause of fever. Excessive reliance on RDTs may cause overlooking potentially severe non malarial febrile illnesses (NMFI) in these cases. In countries or areas where transmission intensity remains very high, fever management in children (especially in the rainy season) should probably remain presumptive, as a test-based management may not be safe, nor cost effective. In contrast, in countries with low transmission, including those targeted for malaria elimination, RDTs are a key resource to limit unnecessary antimalarial prescription and to identify pockets of infected individuals. Research should focus on very sensitive tools for infection on one side, and on improved tools for clinical management on the other, including biomarkers of clinical malaria and/or of alternative causes of fever.

scholarly journals Evaluation of two new rapid diagnostic tests (RDTs) for the diagnosis of malaria

2013 ◽  
Vol 5 (2) ◽  
pp. 11-15 ◽  
Author(s):  
Fahmida Jahan ◽  
Rubayet Elahi ◽  
Md. Khaja Mohiuddin ◽  
Md. Gulam Musawwir Khan ◽  
Mohammad Shafiul Alam ◽  
...  
Keyword(s):  
Predictive Value ◽  
Gold Standard ◽  
Diagnostic Tests ◽  
Rapid Diagnostic Tests ◽  
Accurate Diagnosis ◽  
The Other ◽  
Antibody Detection ◽  
Resource Limited Settings ◽  
Malaria Rdts ◽  
Resource Limited

Rapid diagnostic tests (RDTs) address the need for accurate diagnosis of malaria, particularly in resource limited settings. In this study, two malaria RDTs were compared with gold standard microscopy: On Site Pf/Pv test detecting Plasmodium falciparum-specific histidine rich protein-2 (Pf HR P2) and P. vivax-specific parasitic lactate dehydrogenase (pLDH) antigens; and SD Bioline anti-Pf/Pv test detecting anti-HR P2 and anti-pL DH antibodies for the diagnosis of P. falciparum and P. vivax infections, respectively. For OnSite test, the overall sensitivity was found 96.2% , specificity 98.2% , positive predictive value (PPV ) 98.2% , negative predictive value (NPV ) 96.4% and agreement with microscopy was found to be 0.94. On the other hand SD Bioline test, the overall sensitivity was 75.4%, specificity 83.7%, PPV 84.3% , NPV 74.5% and agreement with microscopy was 0.59. These data revealed that the R DT based on antigen detection (Onsite test) was more reliable than that based on the antibody detection (SD Bioline test).DOI: http://dx.doi.org/10.3329/bjmm.v5i2.16931 Bangladesh J Med Microbiol 2011; 05 (02): 11-15

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.

scholarly journals Comparing the Performance of HIV Rapid Diagnostic Tests Used in Zambia: a Systematic Review of Clinical Data.

2021 ◽  
Author(s):  
Loveness Mukuka ◽  
Andros Theo ◽  
Mowa Zambwe ◽  
Peter J Chipimo
Keyword(s):  
Systematic Review ◽  
Clinical Data ◽  
Diagnostic Tests ◽  
Rapid Diagnostic Tests ◽  
Fourth Generation ◽  
Hiv Positive ◽  
Third Generation ◽  
Predictive Values ◽  
Rapid Tests ◽  
Positive Results

Objective: To investigate the performance of the HIV RDTs used in Zambia. Method: 2,564 participants aged between 15 and 95 years from two sites in Lusaka province years were tested on OraQuick ADVANCE, Abbot Determine, and then confirmed on Uni-Gold Recombigen. The data from the participants were analyzed using SPSS version 25.0. Results: The 3 RDTs when compared to the 4th generation Abbot Architect results had the following results: OraQuick ADVANCE, Alere Determine and Uni-Gold Ultra, at 95% CI had Sensitivities of: 91.8%, 93.3% and 92.5% respectively. The specificities of OraQuick ADVANCE and Uni-Gold were the same (100.0%; 95% CI: 98.8 -100.0) but slightly different from Alere Determine (99.8%). Positive predictive values at 95% CI were 100% for OraQuick ADVANCE and Uni-Gold and 98.4% for Alere Determine. Negative predictive values (at 95% CIs) were 99.1, 99.2 and 99.1 for OraQuick ADVANCE, Alere Determine, and Uni-Gold Ultra respectively. The results showed that these RDTs could only detect 12 out of every 13 HIV positive results. Conclusion: Third generation RDTs are not effective in detecting acute positive cases. Fourth generation Rapid Tests are required to capture the positive cases being missed out.

scholarly journals Evaluation of Eleven SARS-CoV-2 Antibody Tests by using Samples from Patients with Defined IgG Antibody Titers

2021 ◽  
Author(s):  
Nina Lagerqvist ◽  
Kimia Maleki ◽  
Jenny Verner-Carlsson ◽  
Mikaela Olausson ◽  
Joakim Dillner ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Diagnostic Tests ◽  
Immunofluorescence Assay ◽  
Rapid Diagnostic Tests ◽  
The Other ◽  
Igg Antibody ◽  
Reference Set ◽  
Antibody Titers ◽  
Serial Samples ◽  
Antibody Tests

Abstract We evaluated the performance of eleven SARS-CoV-2 antibody tests using a reference set of heat-inactivated samples from 278 unexposed persons and 258 COVID-19 patients, some of whom contributed serial samples. The reference set included samples with a variation in SARS-CoV-2 IgG antibody titers, as determined by an in-house immunofluorescence assay (IFA). The five evaluated rapid diagnostic tests had an IgG-based specificity of 99.0% and a sensitivity that ranged from 56.3–81.6% and decreased with low IFA titers. The specificity was > 99% for five out of six platform-based tests, and when assessed using samples collected ≥ 22 days after symptom onset, two assays had a sensitivity of > 96%. These two assays also detected samples with low IFA titers more frequently than the other assays. In conclusion, the evaluated antibody tests showed a heterogeneity in their performances and only a few tests performed well with samples having low IFA IgG titers, an important aspect for diagnostics and epidemiological investigations.

scholarly journals Rapid Diagnostic Tests for Malaria Parasites

2002 ◽  
Vol 15 (1) ◽  
pp. 66-78 ◽  
Author(s):  
Anthony Moody
Keyword(s):  
Diagnostic Tests ◽  
New Technology ◽  
Malaria Diagnosis ◽  
Cost Effective ◽  
Rapid Diagnostic Tests ◽  
World Health ◽  
Diagnostic Challenge ◽  
Population Movements ◽  
Endemic Malaria ◽  
Health Organization

SUMMARY Malaria presents a diagnostic challenge to laboratories in most countries. Endemic malaria, population movements, and travelers all contribute to presenting the laboratory with diagnostic problems for which it may have little expertise available. Drug resistance and genetic variation has altered many accepted morphological appearances of malaria species, and new technology has given an opportunity to review available procedures. Concurrently the World Health Organization has opened a dialogue with scientists, clinicians, and manufacturers on the realistic possibilities for developing accurate, sensitive, and cost-effective rapid diagnostic tests for malaria, capable of detecting 100 parasites/μl from all species and with a semiquantitative measurement for monitoring successful drug treatment. New technology has to be compared with an accepted Rgold standardS that makes comparisons of sensitivity and specificity between different methods. The majority of malaria is found in countries where cost-effectiveness is an important factor and ease of performance and training is a major consideration. Most new technology for malaria diagnosis incorporates immunochromatographic capture procedures, with conjugated monoclonal antibodies providing the indicator of infection. Preferred targeted antigens are those which are abundant in all asexual and sexual stages of the parasite and are currently centered on detection of HRP-2 from Plasmodium falciparum and parasite-specific lactate dehydrogenase or Plasmodium aldolase from the parasite glycolytic pathway found in all species. Clinical studies allow effective comparisons between different formats, and the reality of nonmicroscopic diagnoses of malaria is considered.

scholarly journals Comparative Sensitivities and Specificities of Four Rapid Influenza A Antigen Detection Kits for Detection of H1N1, H3N2 and H5N1

2016 ◽  
Vol 5 (3) ◽  
pp. 31
Author(s):  
Shu Shen ◽  
Dawei Shi ◽  
Haiwei Zhou ◽  
Yabin Tian ◽  
Donglai Liu ◽  
...  
Keyword(s):  
Diagnostic Tests ◽  
Influenza A ◽  
Rapid Diagnostic Tests ◽  
Rapid Diagnosis ◽  
Influenza Viruses ◽  
Immunochromatographic Assay ◽  
High Morbidity ◽  
Diagnostic Kits ◽  
Seasonal Epidemics ◽  
Positive Results

<p>Influenza viruses cause seasonal epidemics associated with high morbidity and mortality. Rapid diagnostic tests for the detection of pandemic influenza A virus are valuable for their ease using and accurate diagnosis of influenza. Many rapid influenza diagnostic kits were introduced recently. Hence, the sensitivities and specificities of them for testing influenza viruses need to monitor. In this study, the sensitivities and specificities of four diagnostic immunochromatographic assay kits for H1N1, H3N2, and H5N1 were evaluated. For the detection of the three H1N1, three H3N2 and one H5N1 virus line, rapid diagnostic tests exhibited excellent specificity (all positive). And no false-positive results were obtained. They differed in respect to the sensitivity, especially in the lower haemagglutinin titer. However, all of them achieve the requirements of National Institutes for food and drug Control (NIFDC). Commercial influenza immunochromatographic assay kits are useful tools for the rapid diagnosis of influenza. Nonetheless, confirmatory testing is always recommended.</p>

scholarly journals Correlation of SARS-CoV-2 nucleocapsid antigen and RNA concentrations in nasopharyngeal samples from children and adults using an ultrasensitive and quantitative antigen assay

2021 ◽  
Author(s):  
Nira R. Pollock ◽  
Timothy J. Savage ◽  
Hanna Wardell ◽  
Rose A. Lee ◽  
Anu Mathew ◽  
...  
Keyword(s):  
Diagnostic Tests ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Rapid Diagnostic Tests ◽  
Clinical Samples ◽  
New Approach ◽  
Antigen Assay ◽  
Adults And Children ◽  
Electrochemiluminescence Immunoassay ◽  
Insight Into

Background: Diagnosis of COVID-19 by PCR offers high sensitivity, but the utility of detecting samples with high cycle threshold (Ct) values remains controversial. Currently available rapid diagnostic tests (RDTs) for SARS-CoV-2 nucleocapsid antigens (Ag) have sensitivity well below PCR. The correlation of Ag and RNA quantities in clinical nasopharyngeal (NP) samples is unknown. Methods: An ultrasensitive, quantitative electrochemiluminescence immunoassay for SARS-CoV-2 nucleocapsid (the MSD® S-PLEX® CoV-2 N assay) was used to measure Ag in clinical NP samples from adults and children previously tested by PCR. Results: The S-PLEX Ag assay had a limit of detection (LOD) of 0.16 pg/mL and a cutoff of 0.32 pg/mL. Ag concentrations measured in clinical NP samples (collected in 3.0 mL media) ranged from less than 160 fg/mL to 2.7 ug/mL. Log-transformed Ag concentrations correlated tightly with Ct values. In 35 adult and 101 pediatric PCR-positive samples, sensitivity was 91% (95% CI, 77-98%) and 79% (70-87%), respectively. In samples with Ct ≤ 35, sensitivity was 100% (88-100%) and 96% (88-99%), respectively. In 50 adult and 40 pediatric PCR-negative specimens, specificity was 100% (93-100%) and 98% (87-100%), respectively. Conclusions: Nucleocapsid concentrations in clinical NP samples span 8 orders of magnitude and correlate closely with RNA concentrations (Ct values). The S-PLEX Ag assay had 96-100% sensitivity in samples from children and adults with Ct values ≤ 35, and 98-100% specificity. These results clarify Ag concentration distributions in clinical samples, providing insight into the performance of Ag RDTs and offering a new approach to diagnosis of COVID-19.

scholarly journals Accuracy of an Immunochromatographic Diagnostic Test (ICT Malaria Combo Cassette Test) Compared to Microscopy among under Five-Year-Old Children when Diagnosing Malaria in Equatorial Guinea

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
José-Luis Portero ◽  
Maria Rubio-Yuste ◽  
Miguel Angel Descalzo ◽  
Jose Raso ◽  
Magdalena Lwanga ◽  
...  
Keyword(s):  
Thin Films ◽  
Diagnostic Accuracy ◽  
Diagnostic Test ◽  
Diagnostic Tests ◽  
Malaria Diagnosis ◽  
Cost Effective ◽  
Rapid Diagnostic Tests ◽  
Equatorial Guinea ◽  
Immunochromatographic Test ◽  
Under Five

Conventional malaria diagnosis based on microscopy raises serious difficulties in weak health systems. Cost-effective and sensitive rapid diagnostic tests have been recently proposed as alternatives to microscopy. In Equatorial Guinea, a study was conducted to assess the reliability of a rapid diagnostic test compared to microscopy. The study was designed in accordance with the directives of the Standards for Reporting Diagnostic Accuracy Initiative (STARD). Peripheral thick and thin films for the microscopy diagnosis and a rapid immunochromatographic test (ICT Malaria Combo Cassette Test) were performed on under five-year-old children with malaria suspicion. The ICT test detected Plasmodium spp. infection with a sensitivity of 81.5% and a specificity of 81.9% while P. falciparum diagnosis occurred with a sensitivity of 69.7% and a specificity of 73.7%. The sensitivity of the ICT test increased with higher parasitemias. The general results showed little concordance between the ICT test and microscopy (kappa = 0.28, se: 0.04). In Equatorial Guinea, the ICT Malaria Combo Cassette Test has proven to be an acceptable test to detect high P. falciparum parasitemias. However, the decrease of sensitivity at medium and low parasitemias hampers that ICT can replace properly performed microscopy at present in the diagnosis of malaria in children.

scholarly journals Modelling the cost-effectiveness of introducing subsidised malaria rapid diagnostic tests in the private retail sector in sub-Saharan Africa

2020 ◽  
Vol 5 (5) ◽  
pp. e002138
Author(s):  
David Bath ◽  
Catherine Goodman ◽  
Shunmay Yeung
Keyword(s):  
Cost Effectiveness ◽  
Diagnostic Tests ◽  
Cost Effective ◽  
Rapid Diagnostic Tests ◽  
Sub Saharan Africa ◽  
Small Scale ◽  
Retail Sector ◽  
First Line ◽  
Sub Saharan ◽  
The Cost

BackgroundOver the last 10 years, there has been a huge shift in malaria diagnosis in public health facilities, due to widespread deployment of rapid diagnostic tests (RDTs), which are accurate, quick and easy to use and inexpensive. There are calls for RDTs to be made available at-scale in the private retail sector where many people with suspected malaria seek care. Retail sector RDT use in sub-Saharan Africa (SSA) is limited to small-scale studies, and robust evidence on value-for-money is not yet available. We modelled the cost-effectiveness of introducing subsidised RDTs and supporting interventions in the SSA retail sector, in a context of a subsidy programme for first-line antimalarials.MethodsWe developed a decision tree following febrile patients through presentation, diagnosis, treatment, disease progression and further care, to final health outcomes. We modelled results for three ‘treatment scenarios’, based on parameters from three small-scale studies in Nigeria (TS-N), Tanzania (TS-T) and Uganda (TS-U), under low and medium/high transmission (5% and 50% Plasmodium falciparum (parasite) positivity rates (PfPR), respectively).ResultsCost-effectiveness varied considerably between treatment scenarios. Cost per disability-adjusted life year averted at 5% PfPR was US$482 (TS-N) and US$115 (TS-T) and at 50% PfPR US$44 (TS-N) and US$45 (TS-T), from a health service perspective. TS-U was dominated in both transmission settings.ConclusionThe cost-effectiveness of subsidised RDTs is strongly influenced by treatment practices, for which further evidence is required from larger-scale operational settings. However, subsidised RDTs could promote increased use of first-line antimalarials in patients with malaria. RDTs may, therefore, be more cost-effective in higher transmission settings, where a greater proportion of patients have malaria and benefit from increased antimalarial use. This is contrary to previous public sector models, where RDTs were most cost-effective in lower transmission settings as they reduced unnecessary antimalarial use in patients without malaria.

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