Novel Diagnostic Methods in Coronavirus Testing

Coronavirus Disease-19, an infectious disease caused by SARS-COV-2 (Severe Acute Respiratory Syndrome- Coronavirus-2) has begun at the end of 2019 causing a global pandemic. The number of cases are increasing exponentially and also so far there have been more than 3 lakh deaths. Some of the symptoms include common cold, respiratory distress and breathing difficulty. Some of the newly reported cases do not show any of the symptoms. Main diagnostic tests include RT-PCR and serologic tests, which are effective and quick. RT-PCR, ELISA (using different components), swab test, serologic test, nasopharyngeal aspirates, and chest-CT's are few of the diagnostic tests conducted to identify the state of the body. Preventative measures like self-isolation, social distancing, less interactions, mainly maintenance of good hygiene should be taken care. Due to advancement in various technologies, there is a constant search for different diagnostic testing methods to possibly find instant and accurate results, due to the drastic increase in the number of cases worldwide and has become a pandemic problem. Imaging using CT-Scan and radiographic modalities can also be used to consider the progression of the covid-19 caused by SARS-COV-2. The guaranteed treatment has still not been found but using few drugs show rapid or slow and unpredictable recovery rates. RT-PCR (Swab-test) and serologic tests are found to be instant and accurate.

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Review of the Microbiological Diagnostic Approaches of COVID-19

Frontiers in Public Health ◽

10.3389/fpubh.2021.592500 ◽

2021 ◽

Vol 9 ◽

Author(s):

Ada Melo-Vallès ◽

Clara Ballesté-Delpierre ◽

Jordi Vila

Keyword(s):

Diagnostic Tests ◽

Diagnostic Testing ◽

World Health ◽

Rt Pcr ◽

Exponential Increase ◽

Rapid Spread ◽

The World ◽

Diagnostic Approaches ◽

Health Organization ◽

Short Time

On March 12, the World Health Organization declared a pandemic following the exponential increase of SARS-CoV-2 cases. The rapid spread of the virus is due to both its high infectivity and the free circulation of unrecognized infectious cases. Thus, diagnostic testing is a key element to prevent further dissemination of the virus. Urged by WHO's call, laboratories worldwide have been working on nucleic acid tests protocols and immunoassays that became available, albeit poorly validated, within a comparatively short time. Since then, external studies evaluating these diagnostic tests have been published. The present study is a review of the COVID-19 diagnostic approaches, discussing both direct and indirect microbiological diagnoses. A compendium of the literature on commercial assays kits available to date is provided together with the conclusions drawn as well as RT-PCR protocols published by the WHO. Briefly, diagnostic accuracy varies according to time elapsed since symptom onset and evolves together with understanding of the COVID-19 disease. Taking into account all these variables will allow determining the most adequate diagnostic test to use and how to optimize diagnostic testing for COVID-19.

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

Journal of Clinical Medicine ◽

10.3390/jcm9051515 ◽

2020 ◽

Vol 9 (5) ◽

pp. 1515 ◽

Cited By ~ 17

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.

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Comparison of Diagnostic Tests for Detection of Bovine Rotavirus a in Calf Feces

Macedonian Veterinary Review ◽

10.2478/macvetrev-2020-0033 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Shama Ranjan Barua ◽

Shariful Islam ◽

А.М.А.М. Zonaed Siddiki ◽

Md Masuduzzaman ◽

Mohammad Alamgir Hossain ◽

...

Keyword(s):

Diagnostic Tests ◽

Rapid Test ◽

Diagnostic Methods ◽

Diagnostic Tools ◽

Rt Pcr ◽

Fecal Samples ◽

Rotavirus A ◽

Bovine Rotavirus ◽

Test Elisa ◽

Calf Mortality

AbstractBovine rotavirus A (BRVA) is a frequent causative agent of diarrhea in neonatal calves. Accurate and rapid diagnosis is crucial to prevent calf mortality from BRVA induced diarrhea. Currently, variety of diagnostic methods are being used to detect BRVA from calves’ feces: antibody-based rapid test and ELISA, and molecular-based RT-PCR and RT-qPCR. The aim of the study was to evaluate the accuracy (sensitivity and specificity) of the rapid test (Immunochromatography), ELISA, and RT-PCR assays, using RT-qPCR as the gold standard, in detection of BRVA in diarrheic calves’ fecal samples. One hundred (n=100) clinically diarrheic fecal samples were tested with four different diagnostic tools. The percent of samples positive by rapid test, ELISA, RT-PCR and RT-qPCR was 10%, 16%, 17%, and 33%, respectively. The agreement between different assays was 75% to 99%. The highest agreement was observed between ELISA and RT-PCR assay (99%). The lowest agreement was recorded (75%) between rapid test and RT-qPCR. The sensitivity of the rapid test, ELISA, and RT-PCR were 30%, 49%, and 52%, respectively when compared to the reference test (RT-qPCR), whereas specificity was 100% for all assays. In conclusion, none of the frequently used diagnostic tests showed a satisfactory level of sensitivity to identify BRVA in calves’ feces. Therefore, the use of a more sensitive rapid test should be used to identify infected calves in field conditions in order to prevent calf mortality from rotaviral diarrhea.

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Lipoarabinomannan as a Point-of-Care Assay for Diagnosis of Tuberculosis: How Far Are We to Use It?

Frontiers in Microbiology ◽

10.3389/fmicb.2021.638047 ◽

2021 ◽

Vol 12 ◽

Author(s):

Julio Flores ◽

Juan Carlos Cancino ◽

Leslie Chavez-Galan

Keyword(s):

Diagnostic Tests ◽

Point Of Care ◽

Diagnostic Testing ◽

Public Health Problem ◽

Etiologic Agent ◽

Diagnostic Methods ◽

World Health ◽

Soluble Form ◽

Health Organization ◽

Low Sensitivity

Tuberculosis (TB) is still a severe public health problem; the current diagnostic tests have limitations that delay treatment onset. Lipoarabinomannan (LAM) is a glycolipid that is a component of the cell wall of the bacillus Mycobacterium tuberculosis, the etiologic agent of TB. This glycolipid is excreted as a soluble form in urine. The World Health Organization has established that the design of new TB diagnostic methods is one of the priorities within the EndTB Strategy. LAM has been suggested as a biomarker to develop diagnostic tests based on its identification in urine, and it is one of the most prominent candidates to develop point-of-care diagnostic test because urine samples can be easily collected. Moreover, LAM can regulate the immune response in the host and can be found in the serum of TB patients, where it probably affects a wide variety of host cell populations, consequently influencing the quality of both innate and adaptive immune responses during TB infection. Here, we revised the evidence that supports that LAM could be used as a tool for the development of new point-of-care tests for TB diagnosis, and we discussed the mechanisms that could contribute to the low sensitivity of diagnostic testing.

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Evaluation of the validity of Ag PANBIO-COVID19 in the diagnosis of SARS-CoV-2 infection in asymptomatic or mildly infected patients

Revista Española de Quimioterapia ◽

10.37201/req/054.2021 ◽

2021 ◽

Author(s):

Paula Gras-Valenti ◽

Inmaculada Vidal ◽

Inés Montiel-Higuero ◽

Isabel Escribano ◽

Natividad Algado-Selles ◽

...

Keyword(s):

Sensitivity And Specificity ◽

Diagnostic Tests ◽

Diagnostic Testing ◽

High Viral Load ◽

Reference Standard ◽

Rt Pcr ◽

Asymptomatic Group ◽

Symptomatic Group ◽

Asymptomatic Patients

Objective. To assess the validity of SARS-CoV-2 Antigen (Ag) detection for the diagnosis of SARS-CoV-2 infection in mildly infected or asymptomatic patients. Material and methods. Observational study to evaluate diagnostic tests. Non-hospitalized patients with indication for diagnostic testing for SARS-CoV-2 infection were included. The diagnostic test to be evaluated was the determination of Ag and as a reference standard to determine the presence of viral RNA the RT-PCR was used. Results. A total of 494 patients were included. Of these 71.5% (353/494) had symptoms and 28.5% (141/494) were asymptomatic (presurgery screening (35/494) and confirmed case-contact (106/494). The overall sensitivity of the Ag test was 61.1% and the specificity was 99.7%. The sensitivity and specificity in the asymptomatic group were 40% and 100% respectively, and in the symptomatic group 63.5% and 99.6% respectively. In turn, the sensitivity and specificity in the group of symptomatic patients varied according to the time of symptom evolution: in patients with recent symptoms, they were 71.4% and 99.6% respectively, while in patients with symptoms of more than 5 days of evolution, they were 26.7% and 100% respectively. In all groups studied, the presence of antigen is associated with a high viral load (Ct<30 cycles). Conclusions. The use of Ag detection test is not indicated for the diagnosis of SARS-CoV-2 infection in asymptomatic patients or with symptoms of more than 5 days of evolution, but it could be useful in patients with symptoms of 1-5 days of evolution.

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Navigating the Diagnostics of COVID-19

American Journal of Clinical Pathology ◽

10.1093/ajcp/aqaa161.299 ◽

2020 ◽

Vol 154 (Supplement_1) ◽

pp. S137-S137

Author(s):

A Sanyaolu ◽

C Okorie ◽

A Marinkovic ◽

O Ayodele ◽

A Abbasi ◽

...

Keyword(s):

Protein Gene ◽

Diagnostic Testing ◽

Pcr Amplification ◽

Ground Glass Opacity ◽

Diagnostic Methods ◽

Screening Methods ◽

Rt Pcr ◽

Serological Tests ◽

Advantages And Disadvantages ◽

Virus Rna

Abstract Introduction/Objective The recent outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) began in Hubei province, China in December 2019 and has spread worldwide at an alarming rate. With millions of individuals infected and over two hundred thousand deaths, the necessity to develop fast and efficient diagnostic methods is of high importance. Diagnostic modalities rely on a combination of epidemiology, clinical presentation, laboratory examination, and appropriate imaging to diagnose and distinguish SARS-CoV-2 from other pulmonary infections. The purpose of this paper is to report on currently available diagnostic screening methods for patients infected with SARS-CoV-2 to guide frontline healthcare workers involved with COVID-19 patient care. Methods An electronic literature search was performed for peer-reviewed articles published from January 1, 2020, until April 26, 2020. Articles were then reviewed and included based on the applicability to the topic. Results The preferred diagnostic approach is reverse transcription of the virus’ RNA followed by PCR amplification (RT-PCR). This method recognizes the gene-specific primers to target various viral protein genes, such as the envelope protein gene or the nucleocapsid protein gene, which enables this test to be both sensitive and specific toward SARS-CoV-2. However, this method has been proven to be time-consuming taking hours-to-days for the results. In order to improve the speed and efficiency of diagnostics, newer rapid diagnostic serological tests are being developed for testing SARS-CoV-2, each with its own unique advantages and disadvantages. They could potentially be used as triage tests to rapidly identify patients who are very likely to have COVID-19 in combination with other accurate diagnostic methods. Conclusion Therefore, a combination of diagnostic testing used in a timely manner may be beneficial for the rapid and accurate detection of SARS-CoV-2. This was evident in cases where despite initial negative RT-PCR tests for various patients, who later demonstrate chest CT scans with various degrees of consolidation and ground-glass opacity. Thus establishing the need for radiology diagnosis to be complementary to RT-PCR for COVID-19 patients. Hopefully, the continuous development and use of rapid diagnostic tests and the implementation of public health measures will help control the spread of the disease.

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Accuracy of malaria diagnostic tests performed on non-invasively collected samples: a systematic review and meta-analysis

BMJ Global Health ◽

10.1136/bmjgh-2021-005634 ◽

2021 ◽

Vol 6 (6) ◽

pp. e005634

Author(s):

Celestin Danwang ◽

Jean Jacques Noubiap ◽

Jacob Souopgui ◽

Jean Gaudart ◽

Jean Cyr Yombi ◽

...

Keyword(s):

Systematic Review ◽

Diagnostic Tests ◽

Meta Analysis ◽

Diagnostic Testing ◽

Malaria Diagnosis ◽

Substantial Improvement ◽

Diagnostic Methods ◽

Data Sets ◽

Overall Performance ◽

Sensitivity Specificity

BackgroundDuring the last decade, many studies have assessed the performance of malaria tests on non-invasively collected specimens, but no systematic review has hitherto estimated the overall performance of these tests. We report here the first meta-analysis estimating the diagnostic performance of malaria diagnostic tests performed on saliva, urine, faeces, skin odour (‘sniff and tell’) and hair, using either microscopy or PCR on blood sample as reference test.MethodsWe searched on PubMed, EMBASE, African Journals Online and Cochrane Infectious Diseases from inception until 19 January 2021 for relevant primary studies. A random effects model was used to estimate the overall performance of various diagnostic methods on different types of specimen.ResultsEighteen studies providing 30 data sets were included in the meta-analysis. The overall sensitivity, specificity and diagnostic OR (DOR) of PCR were 84.5% (95% CI 79.3% to 88.6%), 97.3% (95% CI 95.3% to 98.5%) and 184.9 (95% CI 95.8 to 356.9) in saliva, respectively; 57.4% (95% CI 41.4% to 72.1%), 98.6% (95% CI 97.3% to 99.3%) and 47.2 (95% CI 22.1 to 101.1) in urine, respectively. The overall sensitivity, specificity and DOR of rapid diagnostic test for malaria in urine was 59.8% (95% CI 40.0% to 76.9%), 96.9% (95% CI 91.0% to 99.0%) and 30.8 (95% CI:23.5 to 40.4).ConclusionIn settings where PCR is available, saliva and urine samples should be considered for PCR-based malaria diagnosis only if blood samples cannot be collected. The performance of rapid diagnostic testing in the urine is limited, especially its sensitivity. Malaria testing on non-invasively collected specimen still needs substantial improvement.

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Occurrence of reovirus (ARV) infections in poultry flocks in Poland in 2010–2017

Journal of Veterinary Research ◽

10.2478/jvetres-2018-0079 ◽

2018 ◽

Vol 62 (4) ◽

pp. 421-426

Author(s):

Hanna Czekaj ◽

Wojciech Kozdruń ◽

Natalia Styś-Fijoł ◽

Jowita Samanta Niczyporuk ◽

Karolina Piekarska

Keyword(s):

Nested Pcr ◽

Diagnostic Tests ◽

Broiler Chickens ◽

Population Based ◽

Yolk Sac ◽

Diagnostic Methods ◽

Avian Reovirus ◽

Rt Pcr ◽

Internal Organs ◽

Chicken Embryos

AbstractIntroduction: Avian reovirus (ARV) infections in poultry populations are reported worldwide. The reovirus belongs to the genus Orthoreovirus, family Reoviridae. The aim of the study was to evaluate the incidence of ARV infections in the poultry population based on diagnostic tests performed in 2010–2017.Material and Methods: Samples of the liver and spleen were collected from sick birds suspected of ARV infection and sent for diagnostics. Isolation was performed in 5–7-day-old SPF chicken embryos infected into the yolk sac with homogenates of internal organs of sick birds. Four primer pairs were used to detect the σNS, σC, σA, and µA ARV RNA gene fragments. A nested PCR was used for the detection of the σNS and σC genes.Results: In 2010–2017, ARV infection was found in birds from 81 flocks of broiler chickens and/or layers, 8 flocks of slaughter turkeys, and in 4 hatchery embryos at 17–20 days of incubation. The primers used in RT-PCR and nested PCR did not allow effective detection of ARV RNA in all virus-positive samples.Conclusion: The problem of ARV infections in the poultry population in Poland still persist. The primers used for various ARV segments in RT-PCR and nested PCR did not allow effective detection of RNA in the visceral organs of sick birds. The presented results confirm the necessity of using classical diagnostic methods (isolation in chicken embryos, AGID).

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Challenges in Interpretation of Diagnostic Test Results in a Mumps Outbreak in a Highly Vaccinated Population

Clinical and Vaccine Immunology ◽

10.1128/cvi.00542-16 ◽

2016 ◽

Vol 24 (2) ◽

Cited By ~ 9

Author(s):

L. A. Trotz-Williams ◽

N. J. Mercer ◽

K. Paphitis ◽

J. M. Walters ◽

D. Wallace ◽

...

Keyword(s):

Diagnostic Tests ◽

Diagnostic Testing ◽

Local Area ◽

Case Definition ◽

Test Results ◽

Rt Pcr ◽

Mmr Vaccine ◽

Published Report ◽

The World ◽

Outbreak Case

ABSTRACT In spite of a greatly reduced incidence rate due to vaccination, mumps outbreaks continue to occur in several areas of the world, sometimes in vaccinated populations. This article describes an outbreak in a highly vaccinated population in southwestern Ontario, Canada, and the challenges encountered in interpreting the results of diagnostic tests used in the outbreak. During the outbreak, patients were interviewed and classified according to the outbreak case definition, and specimens were collected for diagnostic testing according to Ontario guidelines. Twenty-seven individuals were classified as confirmed cases (n = 19) or suspect cases (n = 8) according to the case definition, only 9 of which were laboratory-confirmed cases: 7 confirmed by reverse transcriptase PCR (RT-PCR) and 2 by IgM serology. All 19 confirmed cases represented patients who were associated with secondary schools in the local area and had been vaccinated against mumps with one (n = 2) or two (n = 17) doses of the measles-mumps-rubella (MMR) vaccine. This is the first published report of an outbreak of mumps in Ontario in which all confirmed cases had been vaccinated against the disease. It highlights the limitations of and difficulties in interpreting current mumps diagnostic tests when used in vaccinated individuals.

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Comparison and analysis of various complementary diagnosis methods for the current situation and problems of COVID-19 diagnosis

10.1101/2021.01.14.21249620 ◽

2021 ◽

Author(s):

Hee Jin Huh ◽

Seok Lae Chae ◽

Dong-Min Kim

Keyword(s):

Diagnostic Tests ◽

Diagnostic Methods ◽

Current Status ◽

Enzyme Linked Immunosorbent Assay ◽

Fluorescence Immunoassay ◽

Rt Pcr ◽

Chain Reaction ◽

Patient Symptom ◽

Study Population ◽

Polymerase Chain

AbstractWe evaluated and compared the diagnostic performance of fluorescence immunoassay (FIA) and two types of serological diagnostic tests: enzyme-linked immunosorbent assay (ELISA) and immunochromatographic assay (ICA) for detection of SARS-CoV-2 antigen and antibody to diagnose COVID-19 infections. This study is aimed to analyze and compare the current status and problems of COVID-19 diagnosis and various alternative diagnostic methods that are viable. The enrolled subjects in our study population were tested with real-time polymerase chain reaction (RT-PCR). ELISA and immunochromatographic diagnostic kit were used to diagnose 362 positive and 3010 negative SARS-CoV-2 specimens, and antigen fluorescence immunoassay kit was used on 62 positive and 70 negative SARS-CoV-2 RT-PCR confirmed samples for diagnosis. As a result, categorizing by the patient symptom onset days, PCL COVID19 Total Ab EIA (ELISA) showed the sensitivity of 93.4% from 15 to 21 days, 94.2% from over 22 days, and the specificity of 99.97%. PCL COVID19 IgG/IgM Rapid Gold (ICA) had a sensitivity of 86.9%, 97.4%, and the specificity of 98.14% respectively. PCL COVID19 Ag Rapid FIA sensitivity was 93.8% from 0 to 7 days, 71.4% from 8 to 12 days and specificity was 98.57%. In conclusion, COVID-19 Ab ELISA and ICA, and COVID-19 Ag FIA are all complementary and applicable diagnostic methods to resolve the current problems of COVID-19 diagnosis.

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