Sensitivity and specificity of a rapid test for assessment of exposure to SARS-CoV-2 in a community-based setting in Brazil

AbstractBackgroundWhile the recommended laboratory diagnosis of COVID-19 is a molecular based assay, population-based studies to determine the prevalence of COVID-19 usually use serological assays.ObjectiveTo evaluate the sensitivity and specificity of a rapid diagnostic test for COVID-19 compared to quantitative reverse transcription polymerase chain reaction (qRT-PCR).MethodsWe evaluated the sensitivity using a panel of finger prick blood samples from participants >18 years of age that had been tested for COVID-19 by qRT-PCR. For assessing specificity, we used serum samples from the 1982 Pelotas (Brazil) Birth Cohort participants collected in 2012 with no exposure to SARS-CoV-2.ResultsThe sensitivity of the test was 77.1% (95% CI 66.6 - 85.6), based upon 83 subjects who had tested positive for qRT-PCR at least 10 days before the rapid diagnostic test (RDT). Based upon 100 sera samples, specificity was 98.0% (95% CI 92.9 - 99.8). There was substantial agreement (Kappa score 0.76) between the qRT-PCR results and the RDT.InterpretationThe validation results are well in line with previous assessments of the test, and confirm that it is sufficiently precise for epidemiological studies aimed at monitoring levels and trends of the COVID-19 pandemic.

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COMPARISON OF FOURTH GENERATION ELISA AND RAPID DIAGNOSTIC TEST FOR DIAGNOSIS OF HEPATITIS C VIRUS(HCV) INFECTION IN A TERTIARY CARE HOSPITAL.

10.36106/2000717 ◽

2021 ◽

pp. 15-17

Author(s):

Stuti Kansra Arora ◽

Mala Chhabra ◽

Anuradha Anuradha ◽

Arvind Achra ◽

Nandini Duggal

Keyword(s):

Diagnostic Test ◽

Rapid Diagnostic Test ◽

Sensitivity And Specificity ◽

Treatment Initiation ◽

Tertiary Care ◽

Hcv Infection ◽

Fourth Generation ◽

World Population ◽

Test Results ◽

Blood Samples

Introduction:Hepatitis C virus (HCV) infection has emerged as one of the major global health challenge affecting about 2 - 3% of the world population. Epidemiological studies have shown that HCV infection is a major risk factor for development of Acute hepatitis,chronic liver disease,cirrhosis and Hepatocellular carcinoma (HCC).Early diagnosis of HCV is important to link hepatitis testing to care and treatment initiation. Aim:To compare sensitivity and specificity of rapid diagnostic test (RDT) with fourth generation ELISA Material and Method: This study was conducted in the Department of Microbiology at Atal Bihari Vajpayee Institute of Medical Sciences (formerly Post Graduate Institute of Medical Education and Research) and Dr Ram Manohar Lohia Hospital from January 2018 to December 2018.Blood samples of patients suspected with hepatitis were tested using ELISA and rapid diagnostic test Results: In our study 26378 blood samples were tested for HCV,using fourth generation ELISA.Of these,581(2.20%) samples were found to be positive by ELISA.These HCV positive samples along with equal number of ELISA negative samples were tested by rapid diagnostic test. Sensitivity and specificity of the rapid diagnostic test was found to be 72.98 % and 100% respectively. Discussion:Rapid diagnostic test can be used during emergency hours but their results must be followed by ELISA test results in a tertiary care hospital.Reporting of false negative results should be minimized for rapid linkage to treatment initiation and to avoid silent transmission of infection.

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Seroprevalence of SARS-CoV-2 infection in a municipality in southern Brazil

Research Society and Development ◽

10.33448/rsd-v10i9.17996 ◽

2021 ◽

Vol 10 (9) ◽

pp. e30710917996

Author(s):

Maria Joana Carvalho e Silva ◽

Kassia Kramer ◽

Yasmim Paula Cesco ◽

Kendy Otak ◽

Andréia Machado Cardoso ◽

...

Keyword(s):

Rna Virus ◽

Rapid Test ◽

Epidemiological Studies ◽

Population Based ◽

Southern Brazil ◽

Cross Sectional ◽

Population Based Study ◽

Rapid Spread ◽

And Control ◽

The City

SARS-CoV-2 is an RNA virus, responsible for causing an acute respiratory syndrome, which became known worldwide for its rapid spread and for causing the pandemic of a new disease: COVID-19. Thus, epidemiological studies have been developed in order to determine the extent of the problems and the magnitude of the disease. The present study aimed to evaluate the seroprevalence of SARS-CoV-2 infection and its relationship with socio-demographic and clinical-epidemiological factors in the city of Chapecó, Santa Catarina, Brazil. It was a quantitative, epidemiological, observational, cross-sectional, population-based study with 2179 participants. Socio-demographic, associated behavioral, aggravating and comorbid parameters were evaluated, relating them to positivity or not in the rapid test implemented. The rapid test identified 22.2% of the diagnosed seroprevalence of COVID-19 in the municipality in question. A higher incidence of cases was observed in people living with other people, in people who had contact with positive cases, and in symptomatic patients, corroborating with current studies. The results highlight the importance of clinical-epidemiological studies for the understanding and control of COVID-19.

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Performance Evaluation of Commercial Dengue Diagnostic Tests for Early Detection of Dengue in Clinical Samples

Journal of Tropical Medicine ◽

10.1155/2017/4687182 ◽

2017 ◽

Vol 2017 ◽

pp. 1-4 ◽

Cited By ~ 1

Author(s):

Tuan Nur Akmalina Mat Jusoh ◽

Rafidah Hanim Shueb

Keyword(s):

Dengue Virus ◽

Real Time ◽

Diagnostic Test ◽

Rapid Diagnostic Test ◽

Dengue Infection ◽

Clinical Samples ◽

Enzyme Linked Immunosorbent Assay ◽

Rt Pcr ◽

Serum Samples ◽

Kappa Agreement

The shattering rise in dengue virus infections globally has created a need for an accurate and validated rapid diagnostic test for this virus. Rapid diagnostic test (RDT) and reverse transcription-polymerase chain reaction (RT-PCR) diagnostic detection are useful tools for diagnosis of early dengue infection. We prospectively evaluated the diagnostic performance of nonstructural 1 (NS1) RDT and real-time RT-PCR diagnostic kits in 86 patient serum samples. Thirty-six samples were positive for dengue NS1 antigen while the remaining 50 were negative when tested with enzyme-linked immunosorbent assay (ELISA). Commercially available RDTs for NS1 detection, RTK ProDetect™, and SD Bioline showed high sensitivity of 94% and 89%, respectively, compared with ELISA. GenoAmp® Trioplex Real-Time RT-PCR and RealStar® Dengue RT-PCR tests presented a comparable kappa agreement with 0.722. The result obtained from GenoAmp® Real-Time RT-PCR Dengue test showed that 14 samples harbored dengue virus type 1 (DENV-1), 8 samples harbored DENV-2, 2 samples harbored DENV-3, and 1 sample harbored DENV-4. 1 sample had a double infection with DENV-1 and DENV-2. The NS1 RDTs and real-time RT-PCR tests were found to be a useful diagnostic for early and rapid diagnosis of acute dengue and an excellent surveillance tool in our battle against dengue.

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Diagnosis of Visceral Leishmaniasis by Enzyme-Linked Immunosorbent Assay Using Urine Samples

Clinical and Vaccine Immunology ◽

10.1128/cdli.9.4.789-794.2002 ◽

2002 ◽

Vol 9 (4) ◽

pp. 789-794 ◽

Cited By ~ 3

Author(s):

Mohammad Zahidul Islam ◽

Makoto Itoh ◽

S. M. Shamsuzzaman ◽

Rusella Mirza ◽

Farzana Matin ◽

...

Keyword(s):

Visceral Leishmaniasis ◽

Sensitivity And Specificity ◽

Immunosorbent Assay ◽

Leishmania Donovani ◽

Laboratory Diagnosis ◽

Urine Samples ◽

Enzyme Linked Immunosorbent Assay ◽

Healthy Controls ◽

Serum Samples ◽

Crude Antigen

ABSTRACT A diagnostic method has been developed to detect anti-Leishmania donovani immunoglobulin G (IgG) in urine by enzyme-linked immunosorbent assay (ELISA). In measuring anti-L. donovani IgG, IgA, and IgM in urine, the method performed best in the detection of IgG. The sensitivity and specificity of the assay were determined with panels of urine samples from 62 visceral leishmaniasis (VL) patients, 59 healthy controls from areas of endemicity, 53 healthy controls from areas of nonendemicity, 59 malaria patients, 13 tuberculosis patients, 23 cutaneous leishmaniasis patients, and 7 patients with other diseases. Using L. donovani promastigote crude antigen, the test had 93.5% sensitivity (58 positives of 62 VL patient samples) and 89.3% specificity (191 negatives of 214 non-VL patient samples). The ELISA with acetone-treated L. donovani promastigote antigen raised the sensitivity and specificity to 95.0 and 95.3%, respectively. Western blot analysis revealed that most of the samples that cross-reacted with crude antigen in ELISA did not recognize any antigenic component of L. donovani crude antigen. We also checked 40 serum samples from the same group of VL patients for anti-L. donovani IgG and got 90.0% sensitivity with both crude and acetone-treated antigens. As collection of urine is much easier than collection of serum, the detection of anti-L. donovani IgG in urine with acetone-treated antigen will be useful in epidemiological studies. It could be an adjunct of laboratory diagnosis.

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The Use of NS1 Rapid Diagnostic Test and qRT-PCR to Complement IgM ELISA for Improved Dengue Diagnosis from Single Specimen

Scientific Reports ◽

10.1038/srep27663 ◽

2016 ◽

Vol 6 (1) ◽

Cited By ~ 17

Author(s):

Boon-Teong Teoh ◽

Sing-Sin Sam ◽

Kim-Kee Tan ◽

Jefree Johari ◽

Juraina Abd-Jamil ◽

...

Keyword(s):

Diagnostic Test ◽

Rapid Diagnostic Test ◽

Single Specimen ◽

Qrt Pcr ◽

Igm Elisa

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Evaluation of the performance of three serological tests for diagnosis of Leishmania infantum infection in dogs using latent class analysis

Revista Brasileira de Parasitologia Veterinária ◽

10.1590/s1984-29612020105 ◽

2020 ◽

Vol 29 (4) ◽

Author(s):

Asier Basurco ◽

Alda Natale ◽

Katia Capello ◽

Antonio Fernández ◽

María Teresa Verde ◽

...

Keyword(s):

Sensitivity And Specificity ◽

Leishmania Infantum ◽

Latent Class ◽

Rapid Test ◽

Antibody Test ◽

Latent Class Models ◽

Canine Leishmaniasis ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Serological Tests

Abstract Canine leishmaniasis (CanL) is a disease caused by Leishmania infantum. Serological methods are the most common diagnostic techniques used for the diagnosis of the CanL. The objective of our study was to estimate the sensitivity and specificity of one in-house ELISA kit (ELISA UNIZAR) and three commercially available serological tests (MEGACOR Diagnostik GmbH) including an immunochromatographic rapid test (FASTest LEISH®), an immunofluorescent antibody test (MegaFLUO LEISH®) and an enzyme-linked immunosorbent assay (MegaELISA LEISH®), using latent class models in a Bayesian analysis. Two hundred fifteen serum samples were included. The highest sensitivity was achieved for FASTest LEISH® (99.38%), ELISA UNIZAR (99.37%), MegaFLUO LEISH® (99.36%) followed by MegaELISA LEISH® (98.49%). The best specificity was obtained by FASTest LEISH® (98.43%), followed by ELISA UNIZAR (97.50%), whilst MegaFLUO LEISH® and MegaELISA LEISH® obtained the lower specificity (91.94% and 91.93%, respectively). The results of present study indicate that the immunochromatographic rapid test evaluated FASTest LEISH® show similar levels of sensitivity and specificity to the quantitative commercial tests. Among quantitative serological tests, sensitivity and specificity were similar considering ELISA or IFAT techniques.

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Rapid development of COVID-19 rapid diagnostics for low resource settings: accelerating delivery through transparency, responsiveness, and open collaboration

10.1101/2020.04.29.20082099 ◽

2020 ◽

Cited By ~ 4

Author(s):

Emily R Adams ◽

Yolanda Augustin ◽

Rachel L Byrne ◽

David J Clark ◽

Michael Cocozza ◽

...

Keyword(s):

Rapid Development ◽

Laboratory Diagnosis ◽

Epidemiological Studies ◽

Contact Tracing ◽

Clinical Samples ◽

Respiratory Pathogens ◽

Rapid Diagnostics ◽

Serum Samples ◽

Low Resource Settings ◽

Low Resource

SummaryHere we describe an open and transparent consortium for the rapid development of COVID-19 rapid diagnostics tests. We report diagnostic accuracy data on the Mologic manufactured IgG COVID-19 ELISA on known positive serum samples and on a panel of known negative respiratory and viral serum samples pre-December 2019.In January, Mologic, embarked on a product development pathway for COVID-19 diagnostics focusing on ELISA and rapid diagnostic tests (RDTs), with anticipated funding from Wellcome Trust and DFID.834 clinical samples from known COVID-19 patients and hospital negative controls were tested on Mologic’s IgG ELISA. The reported sensitivity on 270 clinical samples from 124 prospectively enrolled patients was 94% (95% CI: 89.60% - 96.81%) on day 10 or more post laboratory diagnosis, and 96% (95% CI: 84.85% - 99.46%) between 14–21 days post symptom onset. A specificity panel comprising 564 samples collected pre-December 2019 were tested to include most common respiratory pathogens, other types of coronavirus, and flaviviruses. Specificity in this panel was 97% (95% CI: 95.65% - 98.50%).This is the first in a series of Mologic products for COVID-19, which will be deployed for COVID-19 diagnosis, contact tracing and sero-epidemiological studies to estimate disease burden and transmission with a focus on ensuring access, affordability, and availability to low-resource settings.

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Is rapid diagnostic test (malaria Pv/Pf Ag card test) reliable in diagnosing malaria

International Journal of Contemporary Pediatrics ◽

10.18203/2349-3291.ijcp20175565 ◽

2017 ◽

Vol 5 (1) ◽

pp. 92

Author(s):

Vishruti Gandhi Vishruti Gandhi ◽

Prasad Muley ◽

Niyati Parikh ◽

Hardik Gandhi ◽

Akash Mehta

Keyword(s):

Plasmodium Falciparum ◽

Plasmodium Vivax ◽

Diagnostic Test ◽

Rapid Diagnostic Test ◽

Sensitivity And Specificity ◽

Peripheral Blood Smear ◽

Peripheral Smear ◽

Infected Female ◽

Anopheles Mosquitoes ◽

Smear Examination

Background: Malaria is a protozoan disease transmitted by the bite of infected female anopheles mosquitoes is one of the most important parasitic diseases of human with transmission in 109 countries, affecting more than one billion people worldwide. This study was planned to compare the gold standard i.e. peripheral blood smear examination and the newer rapid diagnostic test (malaria plasmodium falciparum/ plasmodium vivax antigen card) to know the diagnostic accuracy of Rapid Diagnostic Test (RDT) kits. Methods: All the suspected cases of WHO defined malaria between 1month to 18 years of age were enrolled in the study.Results: Out of 96 clinically suspected cases of malaria 63 were confirmed by peripheral smear. The age range of participants ranged from 4 months to 17 years. On peripheral smear examination, out of 96 clinically suspected cases, 37 (38.5%) cases were positive for P. vivax, 23 (23.9%) were positive for P. falciparum and 3 (3.1%) were positive for both parasites by microscopy. Sensitivity and specificity of RDT for Plasmodium Vivax is 92.5% and 96.4% respectively. Sensitivity and specificity of RDT for Plasmodium Falciparum is 96.2% and 90%.Conclusions: The rational use of RDTs as a complement to microscopy might give substantial health benefits through earlier treatment, reduction in morbidity and mortality and more rationalized approach for choosing anti-malarial drugs, which in terms may prevent drug resistance.

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Detection of Anti-LipL32 Antibodies in Serum Samples from Horses with Chronic Intraocular Infection with Leptospira spp.

Pathogens ◽

10.3390/pathogens10101325 ◽

2021 ◽

Vol 10 (10) ◽

pp. 1325

Author(s):

Tobias Geiger ◽

Hartmut Gerhards ◽

Bettina Wollanke

Keyword(s):

Sensitivity And Specificity ◽

Aqueous Humor ◽

Screening Method ◽

Rapid Test ◽

High Sensitivity ◽

Agglutination Test ◽

Laboratory Diagnostics ◽

Surgical Removal ◽

Serum Samples ◽

Equine Recurrent Uveitis

Equine recurrent uveitis (ERU) is typically caused by chronic intraocular leptospiral infection in warm-blooded horses in central Europe. The most effective therapy for leptospiral-induced ERU is the surgical removal of diseased vitreous (vitrectomy). Since vitrectomy is a highly specialized and invasive surgery, the indication must be determined very carefully. In order to obtain evidence of intraocular leptospiral infection by laboratory diagnostics in questionable leptospiral ERU-cases, sampling of aqueous humor is required, because serum tests using microscopic agglutination test (MAT) are too unspecific. The SNAP Lepto is a cross-species rapid test for the detection of anti-Lipl32 antibodies that has a high sensitivity (0.97) and specificity (1.00) for the detection of anti-leptospiral antibodies using aqueous humor or vitreous samples, which is comparable to MAT. To evaluate sensitivity and specificity of SNAP Lepto using serum, serum samples from 90 horses with confirmed leptospiral ERU and from 103 ocularly healthy horses were tested by both MAT and SNAP Lepto. Sensitivity was similar for both tests (0.82 vs. 0.79), but specificity was lower for MAT (0.52 vs. 0.95). Sensitivity and specificity are therefore lower in serum samples compared to intraocular samples, however, the SNAP Lepto is far superior to MAT and suitable as a screening method using equine serum.

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