Materiały źródłowe

• #1 Lateral flow test engineering and lessons learned from COVID-19 | Nature Reviews BioengineeringClose bannerClose banner

  https://www.nature.com/articles/s44222-022-00007-3

  Lateral flow tests (LFTs) were adopted at an unprecedented scale during the COVID-19 pandemic, enabling access to testing beyond healthcare settings. […] Key barriers to COVID-19 LFT development and adoption include lack of access to well characterized samples, limited accuracy, lack of connectivity, lack of evidence of cost-effectiveness, regulatory delays and centralized manufacturing capabilities. […] The accuracy and, in particular, the sensitivity of LFTs is lower than that of reference RT-PCR methods, ranging between 34.1% and 88.1% for SARS-CoV-2 antigen LFTs, with an overall specificity of 99.6%. […] The success of COVID-19 antigen LFTs can be in part attributed to the pathophysiology of SARS-CoV-2, that is, its short incubation period and high transmission rates, which are well suited to rapid, frequent testing.

• #2 What is lateral flow testing and how could it be deployed against coronavirus?verifiedverifiedverifiedverifiedverifiedverifiedverifiedverifiedverifiedverified

  https://www.gavi.org/vaccineswork/what-lateral-flow-testing-and-how-could-it-be-deployed-against-coronavirus

  COVID-19 lateral flow tests, also known as COVID-19 rapid diagnostic tests, offer a means of quickly testing for SARS-CoV-2, the virus that causes COVID-19, typically delivering a result in 15-30 minutes. […] However, the speed and convenience of these tests comes at the expense of accuracy, meaning care needs to be taken in the interpretation and communication of results. […] The World Health Organization recommends that rapid diagnostic tests for SARS-CoV-2 must have a minimum sensitivity of 70% and at least 97% specificity. […] Independent tests by the Foundation for Innovative New Diagnostics (FIND) found that one such test, by the South Korean company SD Biosensor, had a clinical specificity of 99.3% and a clinical sensitivity of 76.6% – making it approximately 20% less sensitive than PCR tests.

• #3 Development and Efficacy of Lateral Flow Point-of-Care Testing Devices for Rapid and Mass COVID-19 Diagnosis by the Detections of SARS-CoV-2 Antigen and Anti-SARS-CoV-2 Antibodies

  https://pmc.ncbi.nlm.nih.gov/articles/PMC8534532/

  Viral testing can identify whether a person is currently infected with SARS-CoV-2. […] Antigen tests are immunoassays that detect the presence of a specific COVID-19 viral antigen, e.g., the viral S and/or N proteins, which implies current viral infection. […] Antigen tests, also known as antigen-detecting rapid diagnostic tests (Ag-RDTs), are commonly used to diagnose respiratory pathogens, including influenza viruses and respiratory syncytial viruses. […] Rapid SARS-CoV-2 antigen tests for COVID-19 are one of the most helpful application tests and have provided global governments with several benefits. […] The detection of SARS-CoV-2 antigen has applied the immunoreaction of specific antibodies to recognize the viral proteins, e.g., SARS-CoV-2 N and/or S proteins. […] The evaluation of anti-SARS-CoV2 IgM and IgG antibodies by immunoassays serves epidemiological purposes for COVID-19 that are recognized.

• #4 British manufacturer SureScreen Diagnostics to supply 20 million rapid lateral flow – GOV.UK

  https://www.gov.uk/government/news/british-manufacturer-surescreen-diagnostics-to-supply-20-million-rapid-lateral-flow

  New tests will support the governments drive to deliver rapid testing to those without symptoms to break chains of transmission […] With up to a third of individuals with COVID-19 not displaying symptoms, broadening asymptomatic testing is essential in finding positive cases who may unknowingly pass on the virus in order to break chains of transmission. […] Rapid lateral flow tests strengthen our national response to the virus significantly, helping us to identify the around 1 in 3 people who are asymptomatic and break chains of transmission in our workplaces and communities. […] The kind of large-scale community testing that these tests facilitate is part of the governments COVID-19 winter plan to identify those who may be infectious with coronavirus earlier in order to break the chains of transmission and keep the virus under control.

• #5 A complete guide to Lateral Flow testing – Sante Group

  https://sante-group.com/a-complete-guide-to-lateral-flow-testing/

  As stated in the NHS Test and Trace Guidelines, one in three individuals with COVID-19 do not display any symptoms and are therefore spreading the virus unknowingly. Identifying these individuals is saving lives. […] Lateral flow testing is an established technology, adapted to detect antigens that are present when an individual has contracted COVID-19. […] It is widely recognized that lateral flow testing is a crucial factor in driving down the spread of COVID-19.

• #6 Electrochemical lateral-flow device for rapid COVID-19 antigen-diagnostic testing

  https://pmc.ncbi.nlm.nih.gov/articles/PMC10077809/

  The coronavirus disease (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first detected in December 2019 in Wuhan Hubei Province, China. […] The SARS-CoV-2 virus is spread through coughing, sneezing, or direct contact. The virus enters the respiratory tract, where the peptidase domain of the angiotensin-converting enzyme 2 (ACE2) receptor in the lungs connects to the receptor-binding domain (RBD) of the S protein, advancing SARS-CoV-2 into the host cells. […] Therefore, rapid methods for screening the SARS-CoV-2 virus are required worldwide. […] The COVID-19 pandemic continues to emphasize the need for accurate, quick, and affordable detection procedures for infected patients. […] However, ATKs exhibit poor sensitivity and cannot detect low concentrations of SARS-CoV-2.

• #7 Development and Efficacy of Lateral Flow Point-of-Care Testing Devices for Rapid and Mass COVID-19 Diagnosis by the Detections of SARS-CoV-2 Antigen and Anti-SARS-CoV-2 Antibodies

  https://pmc.ncbi.nlm.nih.gov/articles/PMC8534532/

  The COVID-19 pandemic is an ongoing global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 20202021. […] SARS-CoV-2 is the virus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the COVID-19 pandemic. […] SARS-CoV-2 is a newly discovered positive-sense single-stranded RNA virus that is closely related to bat coronaviruses and pangolin coronaviruses. […] Virus infections start when viral particles bind to host surface cellular receptors. […] Protein modeling experiments on the S protein of the virus suggested that SARS-CoV-2 has sufficient affinity to the angiotensin-converting enzyme 2 (ACE2) receptor on human cells to use them as a cell entry mechanism. […] Molecular tests for COVID-19 are generally divided into two types: viral and antibody testing.

• #8 Electrochemical lateral-flow device for rapid COVID-19 antigen-diagnostic testing

  https://pmc.ncbi.nlm.nih.gov/articles/PMC10077809/

  The coronavirus disease (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first detected in December 2019 in Wuhan Hubei Province, China. […] The SARS-CoV-2 virus is spread through coughing, sneezing, or direct contact. The virus enters the respiratory tract, where the peptidase domain of the angiotensin-converting enzyme 2 (ACE2) receptor in the lungs connects to the receptor-binding domain (RBD) of the S protein, advancing SARS-CoV-2 into the host cells. […] Therefore, rapid methods for screening the SARS-CoV-2 virus are required worldwide. […] The COVID-19 pandemic continues to emphasize the need for accurate, quick, and affordable detection procedures for infected patients. […] However, ATKs exhibit poor sensitivity and cannot detect low concentrations of SARS-CoV-2.

• #9 Development and Efficacy of Lateral Flow Point-of-Care Testing Devices for Rapid and Mass COVID-19 Diagnosis by the Detections of SARS-CoV-2 Antigen and Anti-SARS-CoV-2 Antibodies

  https://pmc.ncbi.nlm.nih.gov/articles/PMC8534532/

  The COVID-19 pandemic is an ongoing global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 20202021. […] SARS-CoV-2 is the virus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the COVID-19 pandemic. […] SARS-CoV-2 is a newly discovered positive-sense single-stranded RNA virus that is closely related to bat coronaviruses and pangolin coronaviruses. […] Virus infections start when viral particles bind to host surface cellular receptors. […] Protein modeling experiments on the S protein of the virus suggested that SARS-CoV-2 has sufficient affinity to the angiotensin-converting enzyme 2 (ACE2) receptor on human cells to use them as a cell entry mechanism. […] Molecular tests for COVID-19 are generally divided into two types: viral and antibody testing.

• #10 Lateral flow test engineering and lessons learned from COVID-19 | Nature Reviews BioengineeringClose bannerClose banner

  https://www.nature.com/articles/s44222-022-00007-3

  Lateral flow tests (LFTs) were adopted at an unprecedented scale during the COVID-19 pandemic, enabling access to testing beyond healthcare settings. […] Key barriers to COVID-19 LFT development and adoption include lack of access to well characterized samples, limited accuracy, lack of connectivity, lack of evidence of cost-effectiveness, regulatory delays and centralized manufacturing capabilities. […] The accuracy and, in particular, the sensitivity of LFTs is lower than that of reference RT-PCR methods, ranging between 34.1% and 88.1% for SARS-CoV-2 antigen LFTs, with an overall specificity of 99.6%. […] The success of COVID-19 antigen LFTs can be in part attributed to the pathophysiology of SARS-CoV-2, that is, its short incubation period and high transmission rates, which are well suited to rapid, frequent testing.

• #11 How the SARS-CoV-2 EUA Antigen Tests Work

  https://asm.org/articles/2020/august/how-the-sars-cov-2-eua-antigen-tests-work

  Antigen tests are not as sensitive as PCR tests and false negatives pose a real problem. […] Limited evidence on performance and use. […] Just because antigen testing can be done more rapidly than most PCR assays does not mean it can be used outside of a certified laboratory or without proper training. […] The 3 assays that have received emergency use authorization from the FDA include the Becton Dickinson (BD) Veritor System, the Quidel Sofia 2 SARS antigen FIA and the Abbott Diagnostics BinaxNOW COVID-19 Ag Card. […] The N protein plays an important role in both SARS-CoV and SARS-CoV-2 infection by packaging viral RNA and aiding in the release of additional viral particles from infected cells. […] A positive result means antigen was detected, but clinical correlation with patient history and other diagnostic information is necessary to determine infection status.

• #12 Recent Advances in Quantum Dot-Based Lateral Flow Immunoassays for the Rapid, Point-of-Care Diagnosis of COVID-19

  https://www.mdpi.com/2079-6374/13/8/786

  Due to its vital role in viral entry and infection, the S/N protein is a primary target for diagnostic tests, such as antigen tests and serological assays. […] A variety of diagnostic methods have been developed to detect viral infections, taking into account the nature of the virus, its characteristics, and the collected patient samples. […] Point-of-care testing (POCT) fits these criteria, as it offers a convenient and self-contained approach for detecting SARS-CoV-2 viral infections. […] Recently, POCT platforms such as lateral flow immunoassays (LFIA) have emerged as simpler, rapid, and cost-effective solutions for diagnosing SARS-CoV-2. […] However, these platforms face challenges that are related to inadequate sensitivity, selectivity, and overall reliability. […] The utilization of point-of-care devices presents several advantages.

• #13 An Introduction to the Lateral Flow Test: Strengths, Limitations and Applications | Technology Networks

  https://www.technologynetworks.com/diagnostics/articles/an-introduction-to-the-lateral-flow-test-strengths-limitations-and-applications-370382

  Most people have probably experienced one or more of the home SARS-CoV-2 LFTs firsthand. The majority of the devices people use at home are designed to test for the presence of the virus itself (i.e., might they be infectious?) rather than for antibodies indicating exposure or vaccination. As such, they are directed to bind to the exposed and accessible antigenic parts of the virus such as the spike, envelope, membrane or nucleocapsid proteins. […] Although SARS-CoV-2 may be the human pathogen that first springs to mind when we think about the applications of LFTs for infectious disease, they have also found utility for detecting a range of targets including the Plasmodium parasites that cause malaria, Mycobacterium tuberculosis, the causative agent of TB, hepatitis B virus and human immunodeficiency virus (HIV).

• #14 Development and Efficacy of Lateral Flow Point-of-Care Testing Devices for Rapid and Mass COVID-19 Diagnosis by the Detections of SARS-CoV-2 Antigen and Anti-SARS-CoV-2 Antibodies

  https://pmc.ncbi.nlm.nih.gov/articles/PMC8534532/

  Viral testing can identify whether a person is currently infected with SARS-CoV-2. […] Antigen tests are immunoassays that detect the presence of a specific COVID-19 viral antigen, e.g., the viral S and/or N proteins, which implies current viral infection. […] Antigen tests, also known as antigen-detecting rapid diagnostic tests (Ag-RDTs), are commonly used to diagnose respiratory pathogens, including influenza viruses and respiratory syncytial viruses. […] Rapid SARS-CoV-2 antigen tests for COVID-19 are one of the most helpful application tests and have provided global governments with several benefits. […] The detection of SARS-CoV-2 antigen has applied the immunoreaction of specific antibodies to recognize the viral proteins, e.g., SARS-CoV-2 N and/or S proteins. […] The evaluation of anti-SARS-CoV2 IgM and IgG antibodies by immunoassays serves epidemiological purposes for COVID-19 that are recognized.

• #15 Compound Interest: #ChemVsCOVID: How lateral flow tests for COVID-19 work

  https://www.compoundchem.com/2021/11/06/lateral-flow-tests/

  The lateral flow tests used for rapid testing for COVID are similar in function to home pregnancy tests. Just as pregnancy tests use antibodies to test for the presence of a specific hormone, COVID lateral flow tests use antibodies to detect the presence of the SARS-CoV-2 virus. […] Sensitivity is a measure of the correct production of positive test results. In other words, it gauges how many patients who have the virus correctly test positive on a lateral flow test. […] Its clear, then, that lateral flow tests are more likely to return false negative results, which could mean infected patients thinking theyre all clear. […] Another component of tests accuracy is specificity, a measure of the correct production of negative results. In other words, it tells us how many patients who are not infected with the virus correctly test negative on a test.

• #16 Science Week: How Covid lateral flow tests work | Maynooth University

  https://www.maynoothuniversity.ie/research/spotlight-research/science-week-how-covid-lateral-flow-tests-work

  Flow processes like those in Covid antigen and pregnancy tests, have become a major area of development in the pharmaceutical industry. […] An example of such technology can be found in lateral flow tests. These are devices that aim to detect the presence of a target substance/molecule in a liquid sample without the need for specialised and expensive equipment. […] The flow test detects a target molecule in the sample, an antigen in the case of Covid-19 and a hormone in the case of a pregnancy test. […] The capillary action in the lateral flow test causes the reactive molecules present in the sample (the antigen for Covid-19 tests, the hormone for pregnancy tests) to flow along the pad and interact with the antibodies present further up, and on the surface, of the pad. […] Hence, the test line will only appear if the target molecule is present and binds to the antibody, indicating a positive result.

• #17 How Do Rapid Antigen Tests Work? | Today’s Clinical Lab

  https://www.clinicallab.com/how-do-rapid-antigen-tests-work-26279

  For COVID-19 or influenza, a sample is taken with a nasopharyngeal swab. The swab is then agitated in a small amount of liquid to suspend the sample and any virus particles. After a couple of minutes, that liquid, called the analyte, is placed in the well at the bottom of the testing cartridge. […] The dehydrated test components include antibodies conjugated to a visualization component (usually gold colloid), which bind to the target antigen. For example, the Abbott rapid antigen test has human IgG specific antibodies to SARS-CoV-2 conjugated to gold colloid. […] For the Abbott COVID-19 test, mouse monoclonal anti-SARS-CoV-2 antibodies are immobilized along the test strip. As the analyte passes across the test line, any SARS-CoV-2 antigen targets in the analyte will bind to the conjugated test antibodies. This means that at the test line, the SARS-CoV-2 antigens act like a bridge between the immobilized test antigens and the gold-conjugated visualization antibodies from the conjugate release pad.

• #18 How Do Rapid Antigen Tests Work? | Today’s Clinical Lab

  https://www.clinicallab.com/how-do-rapid-antigen-tests-work-26279

  For COVID-19 or influenza, a sample is taken with a nasopharyngeal swab. The swab is then agitated in a small amount of liquid to suspend the sample and any virus particles. After a couple of minutes, that liquid, called the analyte, is placed in the well at the bottom of the testing cartridge. […] The dehydrated test components include antibodies conjugated to a visualization component (usually gold colloid), which bind to the target antigen. For example, the Abbott rapid antigen test has human IgG specific antibodies to SARS-CoV-2 conjugated to gold colloid. […] For the Abbott COVID-19 test, mouse monoclonal anti-SARS-CoV-2 antibodies are immobilized along the test strip. As the analyte passes across the test line, any SARS-CoV-2 antigen targets in the analyte will bind to the conjugated test antibodies. This means that at the test line, the SARS-CoV-2 antigens act like a bridge between the immobilized test antigens and the gold-conjugated visualization antibodies from the conjugate release pad.

• #19 How Do Rapid Antigen Tests Work? | Today’s Clinical Lab

  https://www.clinicallab.com/how-do-rapid-antigen-tests-work-26279

  For COVID-19 or influenza, a sample is taken with a nasopharyngeal swab. The swab is then agitated in a small amount of liquid to suspend the sample and any virus particles. After a couple of minutes, that liquid, called the analyte, is placed in the well at the bottom of the testing cartridge. […] The dehydrated test components include antibodies conjugated to a visualization component (usually gold colloid), which bind to the target antigen. For example, the Abbott rapid antigen test has human IgG specific antibodies to SARS-CoV-2 conjugated to gold colloid. […] For the Abbott COVID-19 test, mouse monoclonal anti-SARS-CoV-2 antibodies are immobilized along the test strip. As the analyte passes across the test line, any SARS-CoV-2 antigen targets in the analyte will bind to the conjugated test antibodies. This means that at the test line, the SARS-CoV-2 antigens act like a bridge between the immobilized test antigens and the gold-conjugated visualization antibodies from the conjugate release pad.

• #20 How Do Rapid Antigen Tests Work? | Today’s Clinical Lab

  https://www.clinicallab.com/how-do-rapid-antigen-tests-work-26279

  If there is no COVID-19 antigen in the sample, there is nothing to bind the conjugated antibodies. Those conjugated antibodies are then carried past the antibodies bound to the test line with the analyte, so no line appears, indicating a negative result. […] The specificity of lateral flow tests is generally very high (meaning there is a small chance of false positive results). The U.S. Centers for Disease Control and Prevention quotes a specificity of 90–95 percent for Rapid Influenza Diagnostic Tests. For SARS-CoV-2 rapid antigen tests, a 2021 study by Patriquin et al. indicated that false positives typically only occur when users fail to follow the manufacturer’s instructions, such as using improper buffer conditions, etc. […] Unlike positive results, where you can be quite confident in the result, negative results don’t necessarily mean you are truly negative. With any of these tests, two major aspects influence the possibility of receiving a negative result: the way the sample was acquired and the timing of the infection.

• #21 What Does a Faint Line on a Rapid Test Mean?

  https://www.cedars-sinai.org/newsroom/healthcom-why-even-a-faint-line-on-your-rapid-test-still-means-youre-covid–positive/

  At-home antigen tests work by detecting whether the virus is found in testers nasal secretions, Vail told Health.com. If the window on the testing stick shows two lines, the tester is positive for COVID-19. […] If the line is fainter, the patient is likely to be less sick, less infectious, or might be nearing the end of infection, Vail said. A brighter line indicates the patient has more virus in their body and is likely to be sicker and more infectious. […] The chance of getting a false positive is low with at-home tests, so following the antigen test directions and CDC guidelines to the letter prevents the possibility of spreading the virus to others.

• #22 How Do Rapid Antigen Tests Work? | Today’s Clinical Lab

  https://www.clinicallab.com/how-do-rapid-antigen-tests-work-26279

  If there is no COVID-19 antigen in the sample, there is nothing to bind the conjugated antibodies. Those conjugated antibodies are then carried past the antibodies bound to the test line with the analyte, so no line appears, indicating a negative result. […] The specificity of lateral flow tests is generally very high (meaning there is a small chance of false positive results). The U.S. Centers for Disease Control and Prevention quotes a specificity of 90–95 percent for Rapid Influenza Diagnostic Tests. For SARS-CoV-2 rapid antigen tests, a 2021 study by Patriquin et al. indicated that false positives typically only occur when users fail to follow the manufacturer’s instructions, such as using improper buffer conditions, etc. […] Unlike positive results, where you can be quite confident in the result, negative results don’t necessarily mean you are truly negative. With any of these tests, two major aspects influence the possibility of receiving a negative result: the way the sample was acquired and the timing of the infection.

• #23 COVID-19 testing – NHS

  https://www.nhs.uk/conditions/covid-19-rapid-lateral-flow-test/

  A COVID-19 rapid lateral flow is a test you do yourself to check for COVID-19. […] A rapid lateral flow test is done to check if you have COVID-19. […] If you get a positive COVID-19 rapid lateral flow test result, it means it’s very likely you have COVID-19. […] If you get a negative COVID-19 rapid lateral flow test result, it means it’s unlikely you have COVID-19. […] If your test result could not be read, it’s not possible to say if you had COVID-19 when the test was done.

• #24 What Does a Faint Line on a Rapid Test Mean?

  https://www.cedars-sinai.org/newsroom/healthcom-why-even-a-faint-line-on-your-rapid-test-still-means-youre-covid–positive/

  At-home antigen tests work by detecting whether the virus is found in testers nasal secretions, Vail told Health.com. If the window on the testing stick shows two lines, the tester is positive for COVID-19. […] If the line is fainter, the patient is likely to be less sick, less infectious, or might be nearing the end of infection, Vail said. A brighter line indicates the patient has more virus in their body and is likely to be sicker and more infectious. […] The chance of getting a false positive is low with at-home tests, so following the antigen test directions and CDC guidelines to the letter prevents the possibility of spreading the virus to others.

• #25 What the Darkness of Your COVID Test Line Means

  https://www.verywellhealth.com/covid-rapid-test-line-color-5363078

  At-home rapid antigen tests are widely available and can be a quick way to find out if you have COVID-19. […] If you get a quick, dark line on your COVID test, it’s a pretty clear indicator that you’re positive. […] While there are many factors that can cause a line on a COVID test to be faint or hardly visible, the safe bet is to assume that any line on a test means you’re positive and that you need to take precautions to avoid spreading the virus to others. […] According to experts, both the darkness of the line and how long it takes to appear can show how much of the COVID virus is in your body and how likely you are to spread it to others but there are also some limitations you should be aware of. […] As researchers have learned more about how at-home rapid tests work in the real world, they’ve found that in a lot of cases, how dark the line looks on the test does line up with how much virus is in a person’s body.

• #26 Compound Interest: #ChemVsCOVID: How lateral flow tests for COVID-19 work

  https://www.compoundchem.com/2021/11/06/lateral-flow-tests/

  The lateral flow tests used for rapid testing for COVID are similar in function to home pregnancy tests. Just as pregnancy tests use antibodies to test for the presence of a specific hormone, COVID lateral flow tests use antibodies to detect the presence of the SARS-CoV-2 virus. […] Sensitivity is a measure of the correct production of positive test results. In other words, it gauges how many patients who have the virus correctly test positive on a lateral flow test. […] Its clear, then, that lateral flow tests are more likely to return false negative results, which could mean infected patients thinking theyre all clear. […] Another component of tests accuracy is specificity, a measure of the correct production of negative results. In other words, it tells us how many patients who are not infected with the virus correctly test negative on a test.

• #27 COVID-19 Lateral Flow Test

  https://www.icliniq.com/articles/infectious-diseases/covid-19-lateral-flow-test

  The accuracy of any diagnostic test should consider sensitivity and specificity. Sensitivity means correctly identifying those with the disease, and specificity determines those who do not have the condition. The WHO recommends that rapid diagnostic tests for SARS-CoV-2 have a minimum sensitivity of 70 % and a specificity of at least 97%. Independent tests have found one such test by Biosensor. PCR tests are more reliable than a rapid lateral flow test. However, the high specificity of a lateral flow test helps confirm COVID-19 presence in the body accurately. […] PCR tests detect the virus’s genetic material in a given sample as well as it is accurate, whereas rapid tests detect the proteins from the virus. Lateral flow tests cannot distinguish between infected people who are infectious and those who are no longer transmitting the virus.

• #28 How likely is a positive COVID-19 lateral flow test to be wrong?verifiedverifiedverifiedverifiedverifiedverified

  https://www.gavi.org/vaccineswork/how-likely-positive-lateral-flow-test-covid-19-be-wrong

  Lateral flow tests (LFTs) can tell you if you’re infected with COVID-19 within minutes, rather than waiting 24-48 hours for the results of a PCR test. They’ve been suggested as a means of avoiding self-isolation or ensuring that it is safe to visit vulnerable people. However, because they are less accurate than PCR tests, the results need to be more carefully interpreted. […] A recent Cochrane Review, which combined the results of multiple studies assessing the accuracy of LFTs, found that the average sensitivity of such tests was 72% among people with COVID-19 symptoms, and 58% for people without symptoms. This would mean that in for every 100 people infected with COVID-19 who had symptoms, only 72 of them would test positive on a LFT. […] Because of this relatively low sensitivity, a negative test result cannot guarantee that you aren’t infected – false negatives are reasonably common.

• #29 COVID-19 rapid antigen test – Wikipedia

  https://en.wikipedia.org/wiki/COVID-19_rapid_antigen_test

  Although the specificity of RATs are high (98%-99%), in 2020 RATs were criticized for having a sensitivity as low as 50%; that is, if people with COVID-19 as determined by a positive PCR test were also tested with a RAT, about half the time the RAT would be negative. […] As of 2022, systematic reviews determined that the pooled sensitivities of RATs were 70%-72%. […] RATs were more sensitive when samples had more viral load, as measured by a low PCR „cycle threshold,” and less sensitive when the samples had less viral load. […] In November 2020, a new, marginally more infectious strain of SARS-CoV-2 was identified in the United Kingdom, the SARS-CoV-2 Alpha variant. […] Some strains have been identified with a nucleocapsid mutation (D399N) that does decrease the sensitivity of at least one RAT (Quidel Sofia 2) up to 1,000-fold.

• #30 COVID-19 rapid antigen test – Wikipedia

  https://en.wikipedia.org/wiki/COVID-19_rapid_antigen_test

  COVID-19 rapid antigen tests or RATs, also frequently called COVID-19 lateral flow tests or LFTs, are rapid antigen tests used to detect SARS-CoV-2 infection (COVID-19). […] False positives are very rare; the tests’ specificity is 98%-99%. However, the tests have a sensitivity of 70%-72%, which is lower than COVID-19 polymerase chain reaction (PCR) tests’ sensitivity of 88%-96%. […] Despite this, COVID-19 RATs remain valuable in finding people who would otherwise not know they were infected, helping to prevent further transmission. The tests are more sensitive in the symptomatic and transmissive stages of disease when the viral load is higher. […] COVID-19 rapid antigen tests (RATs) have been widely used for diagnosis of COVID-19. […] Nevertheless, individual countries may have different case definitions of COVID-19; for example, in New Zealand a positive PCR test (not just a RAT) is necessary for a person to be considered a „confirmed case.”

• #31 What is lateral flow testing and how could it be deployed against coronavirus?verifiedverifiedverifiedverifiedverifiedverifiedverifiedverifiedverifiedverified

  https://www.gavi.org/vaccineswork/what-lateral-flow-testing-and-how-could-it-be-deployed-against-coronavirus

  COVID-19 lateral flow tests, also known as COVID-19 rapid diagnostic tests, offer a means of quickly testing for SARS-CoV-2, the virus that causes COVID-19, typically delivering a result in 15-30 minutes. […] However, the speed and convenience of these tests comes at the expense of accuracy, meaning care needs to be taken in the interpretation and communication of results. […] The World Health Organization recommends that rapid diagnostic tests for SARS-CoV-2 must have a minimum sensitivity of 70% and at least 97% specificity. […] Independent tests by the Foundation for Innovative New Diagnostics (FIND) found that one such test, by the South Korean company SD Biosensor, had a clinical specificity of 99.3% and a clinical sensitivity of 76.6% – making it approximately 20% less sensitive than PCR tests.

• #32 How accurate are rapid antigen tests for diagnosing COVID-19? | Cochrane

  https://www.cochrane.org/CD013705/INFECTN_how-accurate-are-rapid-antigen-tests-diagnosing-covid-19

  Tests were most accurate when used in the first week after symptoms began (an average of 82% of confirmed cases had positive antigen tests). […] For people with no symptoms, tests were most accurate in people likely to have been in contact with a case of COVID-19 infection (an average of 64% of confirmed cases had positive antigen tests). […] Different brands of tests varied in accuracy. […] No test met this standard when evaluated in people without symptoms. […] Rapid antigen tests are less accurate when used in people with no symptoms of COVID-19. […] More evidence is needed to understand the accuracy of rapid testing in people without symptoms and the extent to which repeated testing strategies can lead to reduced transmission. […] Antigen tests vary in sensitivity. […] In people with signs and symptoms of COVID-19, sensitivities are highest in the first week of illness when viral loads are higher.

• #33 How likely is a positive COVID-19 lateral flow test to be wrong?verifiedverifiedverifiedverifiedverifiedverified

  https://www.gavi.org/vaccineswork/how-likely-positive-lateral-flow-test-covid-19-be-wrong

  However, if you get a positive test result, you can be more confident that you really are infected. This is because the specificity of LFTs – their ability to accurately diagnose uninfected individuals – is higher, and therefore false positives are highly unlikely. […] Even though LFTs are less sensitive than PCR, the Cochrane Review found that they were most accurate when used during the first week after symptoms developed (when 78% of confirmed cases recorded a positive LFT result). This is most likely because people have more virus in their bodies at this time.

• #34 Lateral flow tests are 95% effective at detecting Covid-19 when used at the onset of symptoms | University of Oxford

  https://www.ox.ac.uk/news/2021-07-14-lateral-flow-tests-are-95-effective-detecting-covid-19-when-used-onset-symptoms

  Lateral flow tests are 95% effective at detecting Covid-19 when used at the onset of symptoms. […] The lateral flow tests detected more than 95 per cent of the cases found by PCR, and correctly identified 89 per cent of cases as negative. […] Previous studies have suggested lateral flow tests may be less sensitive than PCR in detecting Covid-19, particularly among asymptomatic individuals and during the early or late stage of an infection when the viral load is lowest. […] In our study, both shorter duration of symptoms and higher viral load were significantly associated with a positive lateral flow tests. […] Our study is the first study to demonstrate that point-of-care antigen testing using lateral flow tests combined with clinical assessment of symptomatic patients can rapidly and accurately detect SARS-CoV-2 infection in primary care.

• #35 How reliable are lateral flow COVID-19 tests? – The Pharmaceutical Journal

  https://pharmaceutical-journal.com/article/feature/how-reliable-are-lateral-flow-covid-19-tests

  It is estimated that around one-third of people with COVID-19 do not have symptoms and could be spreading the virus unknowingly. […] The target of the lateral flow test is proteins, or antigens, found in the COVID-19 virus. […] If you get a positive result from a lateral flow test, it is extremely likely you are currently infected with COVID-19 and risk infecting others. […] The MHRA has stated that “no test is 100% reliable”, even those that meet regulatory standards for performance and safety. […] This is because, unlike PCR tests, lateral flow tests cannot detect very low levels of coronavirus in a sample. […] The accuracy of lateral flow tests is also dependent on the person who does the test. […] A Cochrane review, published on 24 March 2021, investigated whether commercially available, rapid point-of-care antigen (lateral flow) and molecular tests were accurate enough to diagnose COVID-19 infection reliably.

• #36 How likely is a positive COVID-19 lateral flow test to be wrong?verifiedverifiedverifiedverifiedverifiedverified

  https://www.gavi.org/vaccineswork/how-likely-positive-lateral-flow-test-covid-19-be-wrong

  Lateral flow tests (LFTs) can tell you if you’re infected with COVID-19 within minutes, rather than waiting 24-48 hours for the results of a PCR test. They’ve been suggested as a means of avoiding self-isolation or ensuring that it is safe to visit vulnerable people. However, because they are less accurate than PCR tests, the results need to be more carefully interpreted. […] A recent Cochrane Review, which combined the results of multiple studies assessing the accuracy of LFTs, found that the average sensitivity of such tests was 72% among people with COVID-19 symptoms, and 58% for people without symptoms. This would mean that in for every 100 people infected with COVID-19 who had symptoms, only 72 of them would test positive on a LFT. […] Because of this relatively low sensitivity, a negative test result cannot guarantee that you aren’t infected – false negatives are reasonably common.

• #37

  https://www.prevention.com/health/health-conditions/a38769630/false-positive-covid-test/

  False positive means that you have been delivered a positive result, but are not actually infected with the SARS-CoV-2 virus. […] The false positive rate on rapid antigen testing is rare. One study from 2022 estimated that 0.05% of positive tests were false positives. […] [False positives] are not very common at all, explains Gigi Gronvall, Ph.D., a senior scholar at the Johns Hopkins Center for Health Security, where she has led efforts to track the development of COVID-19 testing. It happens, but it is extremely rare. […] Despite the high specificity of antigen tests, false positive results will occur, the CDC writes. In general, for all diagnostic tests, the lower the prevalence of infection in the community, the higher the proportion of false positive test results. […] False positive results on home COVID antigen tests are rare, especially when it is someone who is symptomatic, says Amesh Adalja, M.D., a senior scholar at the Johns Hopkins Center for Health Security.

• #38 How Do Rapid Antigen Tests Work? | Today’s Clinical Lab

  https://www.clinicallab.com/how-do-rapid-antigen-tests-work-26279

  If there is no COVID-19 antigen in the sample, there is nothing to bind the conjugated antibodies. Those conjugated antibodies are then carried past the antibodies bound to the test line with the analyte, so no line appears, indicating a negative result. […] The specificity of lateral flow tests is generally very high (meaning there is a small chance of false positive results). The U.S. Centers for Disease Control and Prevention quotes a specificity of 90–95 percent for Rapid Influenza Diagnostic Tests. For SARS-CoV-2 rapid antigen tests, a 2021 study by Patriquin et al. indicated that false positives typically only occur when users fail to follow the manufacturer’s instructions, such as using improper buffer conditions, etc. […] Unlike positive results, where you can be quite confident in the result, negative results don’t necessarily mean you are truly negative. With any of these tests, two major aspects influence the possibility of receiving a negative result: the way the sample was acquired and the timing of the infection.

• #39 False positive rapid COVID-19 test: Causes and accuracy

  https://www.medicalnewstoday.com/articles/false-positive-rapid-covid-test

  A false positive result is possible with a rapid COVID-19 test. It happens when a person does not have COVID-19 but still tests positive for the disease. […] Although a rapid COVID-19 test is unlikely to produce a false positive result, possible reasons for inaccurate results include: […] The Food and Drug Administration (FDA) explains that false positive results can occur due to contamination. […] A positive result on an at-home COVID-19 test is usually accurate, but false negatives can occur when a person has no COVID-19 symptoms or their infection happened recently. […] Despite these drawbacks, some researchers have suggested that the speed of return and ability to do more frequent tests may make the rapid antigen test more suitable in many cases than a PCR test. […] Rarely, rapid tests may provide a false positive result. For example, if someone does not follow the package instructions, they may get inaccurate results.

• #40 What is lateral flow testing and how could it be deployed against coronavirus?verifiedverifiedverifiedverifiedverifiedverifiedverifiedverifiedverifiedverified

  https://www.gavi.org/vaccineswork/what-lateral-flow-testing-and-how-could-it-be-deployed-against-coronavirus

  Another issue is that lateral flow tests are unable to distinguish between infected people who are no longer transmitting the virus, and those who are still infectious. […] Even though they are less accurate than PCR tests, their low cost, speed and ease of use makes lateral flow tests particularly attractive to countries that do not have extensive laboratory facilities or trained health workers to easily conduct PCR tests. […] With their high specificity, existing COVID-19 lateral flow tests are potentially useful for confirming that someone suspected of having COVID-19 really has it. […] The hope is that this will enable more people who are infected, but asymptomatic, to be identified and quarantined, reducing transmission of the virus.

• #41 COVID-19 Lateral Flow Test

  https://www.icliniq.com/articles/infectious-diseases/covid-19-lateral-flow-test

  The accuracy of any diagnostic test should consider sensitivity and specificity. Sensitivity means correctly identifying those with the disease, and specificity determines those who do not have the condition. The WHO recommends that rapid diagnostic tests for SARS-CoV-2 have a minimum sensitivity of 70 % and a specificity of at least 97%. Independent tests have found one such test by Biosensor. PCR tests are more reliable than a rapid lateral flow test. However, the high specificity of a lateral flow test helps confirm COVID-19 presence in the body accurately. […] PCR tests detect the virus’s genetic material in a given sample as well as it is accurate, whereas rapid tests detect the proteins from the virus. Lateral flow tests cannot distinguish between infected people who are infectious and those who are no longer transmitting the virus.

• #42 COVID-19 rapid antigen test – Wikipedia

  https://en.wikipedia.org/wiki/COVID-19_rapid_antigen_test

  A study published in 2022 found that the sensitivities of six rapid antigen detection tests were 70.0%-92.9% for the Delta variant and 69.6%-78.3% for the Omicron variant across a range of viral loads; however, for Omicron samples with a low viral load, the sensitivities were 0.0%-23.1%. […] If a COVID-19 RAT is used outside manufacturer recommendations, the result can be false positive. […] Some have raised concerns about the slow deployment and uptake of RATs, and the potential loss of life that might have occurred as a result. […] Various concerns have been raised related to the safety of chemical components contained within RAT kits, which can be toxic to humans if not properly used.

• #43 COVID-19 rapid antigen test – Wikipedia

  https://en.wikipedia.org/wiki/COVID-19_rapid_antigen_test

  Although the specificity of RATs are high (98%-99%), in 2020 RATs were criticized for having a sensitivity as low as 50%; that is, if people with COVID-19 as determined by a positive PCR test were also tested with a RAT, about half the time the RAT would be negative. […] As of 2022, systematic reviews determined that the pooled sensitivities of RATs were 70%-72%. […] RATs were more sensitive when samples had more viral load, as measured by a low PCR „cycle threshold,” and less sensitive when the samples had less viral load. […] In November 2020, a new, marginally more infectious strain of SARS-CoV-2 was identified in the United Kingdom, the SARS-CoV-2 Alpha variant. […] Some strains have been identified with a nucleocapsid mutation (D399N) that does decrease the sensitivity of at least one RAT (Quidel Sofia 2) up to 1,000-fold.

• #44 COVID-19 Test (QuickVue) | QuidelOrtho

  https://www.quidelortho.com/global/en/consumers/quickvue-otc

  The QuickVue COVID-19 Test is a visually read lateral flow immunoassay device intended for the rapid, qualitative detection of SARS-CoV-2 nucleocapsid protein antigens directly in anterior nasal (nares) swab specimens from individuals with signs and symptoms of COVID-19 within the first 5 days from symptom onset. […] This easy-to-use test requires a nasal swab sample to determine a positive or negative result for COVID-19. […] The performance characteristics for SARS-CoV-2 were established from January 2021 to February 2024 when COVID-19 variants Alpha, Delta, and Omicron were dominant. Test accuracy may change as new SARS-CoV-2 viruses emerge.

• #45 Recent Advances in Quantum Dot-Based Lateral Flow Immunoassays for the Rapid, Point-of-Care Diagnosis of COVID-19

  https://www.mdpi.com/2079-6374/13/8/786

  The COVID-19 pandemic has spurred demand for efficient and rapid diagnostic tools that can be deployed at point of care to quickly identify infected individuals. […] Point-of-care testing (POCT) has emerged as a promising alternative due to its user-friendliness, rapidity, and high specificity and sensitivity. […] Immunodiagnostic methods that offer the rapid identification of positive cases are urgently required. […] Quantum dots (QDs), known for their multimodal properties, have shown potential in terms of combating or inhibiting the COVID-19 virus. […] Conventional lateral flow immunoassays (LFAs) have been widely used for diagnostic testing due to their simplicity, low cost, and portability. […] However, they often lack the sensitivity required to accurately detect low viral loads.

• #46 How likely is a positive COVID-19 lateral flow test to be wrong?verifiedverifiedverifiedverifiedverifiedverified

  https://www.gavi.org/vaccineswork/how-likely-positive-lateral-flow-test-covid-19-be-wrong

  Lateral flow tests (LFTs) can tell you if you’re infected with COVID-19 within minutes, rather than waiting 24-48 hours for the results of a PCR test. They’ve been suggested as a means of avoiding self-isolation or ensuring that it is safe to visit vulnerable people. However, because they are less accurate than PCR tests, the results need to be more carefully interpreted. […] A recent Cochrane Review, which combined the results of multiple studies assessing the accuracy of LFTs, found that the average sensitivity of such tests was 72% among people with COVID-19 symptoms, and 58% for people without symptoms. This would mean that in for every 100 people infected with COVID-19 who had symptoms, only 72 of them would test positive on a LFT. […] Because of this relatively low sensitivity, a negative test result cannot guarantee that you aren’t infected – false negatives are reasonably common.

• #47 How the SARS-CoV-2 EUA Antigen Tests Work

  https://asm.org/articles/2020/august/how-the-sars-cov-2-eua-antigen-tests-work

  As of Aug. 27, 2020, the U.S. Food and Drug Administration (FDA) has issued 3 emergency use authorizations (EUAs) for COVID-19 assays that test for the presence of SARS-CoV-2 antigens in patient samples. […] Antigen testing, which tests for the presence of viral proteins, rather than viral RNA or host antibodies, offers a third option. […] Antigen tests are cheaper to produce than PCR tests and can be performed very quickly, making them an option worth considering as a screening tool. […] The advantages and disadvantages of antigen testing for SARS-CoV-2 need to be considered to determine if and when it is a reliable method for COVID-19 diagnosis. […] Antigen testing is cheap and fast. […] Antigen testing may be a useful public health tool. […] Antigen tests are generally considered very accurate when they are positive, they may be helpful in quickly identifying highly infectious individuals within a community.

• #48 COVID-19 Lateral Flow Test

  https://www.icliniq.com/articles/infectious-diseases/covid-19-lateral-flow-test

  The World Health Organization (WHO) and other international organizations have recommended individual testing, mass population testing, and subsequent contact tracing to stop the chain of transmission of the COVID-19 virus. Hence, to control the transmission of the virus, there is an urgent need for large-scale, accurate, affordable, and rapid diagnostic testing assays. Advanced research should focus on developing a testing kit that is accurate in diagnosing the infection. The compact and easy-to-use lateral flow devices require no specialist training or equipment and are suitable for mass testing.

• #49 Lateral flow test engineering and lessons learned from COVID-19 | Nature Reviews BioengineeringClose bannerClose banner

  https://www.nature.com/articles/s44222-022-00007-3

  Lateral flow tests (LFTs) were adopted at an unprecedented scale during the COVID-19 pandemic, enabling access to testing beyond healthcare settings. […] Key barriers to COVID-19 LFT development and adoption include lack of access to well characterized samples, limited accuracy, lack of connectivity, lack of evidence of cost-effectiveness, regulatory delays and centralized manufacturing capabilities. […] The accuracy and, in particular, the sensitivity of LFTs is lower than that of reference RT-PCR methods, ranging between 34.1% and 88.1% for SARS-CoV-2 antigen LFTs, with an overall specificity of 99.6%. […] The success of COVID-19 antigen LFTs can be in part attributed to the pathophysiology of SARS-CoV-2, that is, its short incubation period and high transmission rates, which are well suited to rapid, frequent testing.

• #50 Azthena logo with the word Azthena

  https://www.news-medical.net/news/20230123/Review-on-lateral-flow-test-use-spearheaded-by-SARS-CoV-2-pandemic.aspx

  Major roadblocks in LFT development and use include the lack of accessibility to well-characterized samples for testing and validation, low sensitivity, limited digital connectivity, scarce cost-efficacy evidence, delays in regulatory processes, and centralized manufacture of materials. […] Observations from the pandemic have shown that LFT self-testing at a large scale could offer several benefits, such as early identification and prompt self-isolation, increased accessibility to diagnostic tests, increased frequency of testing, increased compliance with public health measures, curtailed viral transmission, and facilitated early recovery. […] However, incorporating bioengineering approaches, machine learning, digitization, and multiplexing would require global collaborative efforts, regulatory harmonization, and an increase in funding to improve research infrastructure and increase the availability of suitable reagents. […] Efforts must be made to overcome LFT shortcomings, such as high false-negative rates, to provide next-generation diagnostic LFTs, with an equitable distribution, across the globe, to improve global preparedness against pathogens.

• #51 Azthena logo with the word Azthena

  https://www.news-medical.net/news/20230123/Review-on-lateral-flow-test-use-spearheaded-by-SARS-CoV-2-pandemic.aspx

  Major roadblocks in LFT development and use include the lack of accessibility to well-characterized samples for testing and validation, low sensitivity, limited digital connectivity, scarce cost-efficacy evidence, delays in regulatory processes, and centralized manufacture of materials. […] Observations from the pandemic have shown that LFT self-testing at a large scale could offer several benefits, such as early identification and prompt self-isolation, increased accessibility to diagnostic tests, increased frequency of testing, increased compliance with public health measures, curtailed viral transmission, and facilitated early recovery. […] However, incorporating bioengineering approaches, machine learning, digitization, and multiplexing would require global collaborative efforts, regulatory harmonization, and an increase in funding to improve research infrastructure and increase the availability of suitable reagents. […] Efforts must be made to overcome LFT shortcomings, such as high false-negative rates, to provide next-generation diagnostic LFTs, with an equitable distribution, across the globe, to improve global preparedness against pathogens.

• #52 How reliable are lateral flow COVID-19 tests? – The Pharmaceutical Journal

  https://pharmaceutical-journal.com/article/feature/how-reliable-are-lateral-flow-covid-19-tests

  It is estimated that around one-third of people with COVID-19 do not have symptoms and could be spreading the virus unknowingly. […] The target of the lateral flow test is proteins, or antigens, found in the COVID-19 virus. […] If you get a positive result from a lateral flow test, it is extremely likely you are currently infected with COVID-19 and risk infecting others. […] The MHRA has stated that “no test is 100% reliable”, even those that meet regulatory standards for performance and safety. […] This is because, unlike PCR tests, lateral flow tests cannot detect very low levels of coronavirus in a sample. […] The accuracy of lateral flow tests is also dependent on the person who does the test. […] A Cochrane review, published on 24 March 2021, investigated whether commercially available, rapid point-of-care antigen (lateral flow) and molecular tests were accurate enough to diagnose COVID-19 infection reliably.

• #53 British manufacturer SureScreen Diagnostics to supply 20 million rapid lateral flow – GOV.UK

  https://www.gov.uk/government/news/british-manufacturer-surescreen-diagnostics-to-supply-20-million-rapid-lateral-flow

  New tests will support the governments drive to deliver rapid testing to those without symptoms to break chains of transmission […] With up to a third of individuals with COVID-19 not displaying symptoms, broadening asymptomatic testing is essential in finding positive cases who may unknowingly pass on the virus in order to break chains of transmission. […] Rapid lateral flow tests strengthen our national response to the virus significantly, helping us to identify the around 1 in 3 people who are asymptomatic and break chains of transmission in our workplaces and communities. […] The kind of large-scale community testing that these tests facilitate is part of the governments COVID-19 winter plan to identify those who may be infectious with coronavirus earlier in order to break the chains of transmission and keep the virus under control.

• #54 British manufacturer SureScreen Diagnostics to supply 20 million rapid lateral flow – GOV.UK

  https://www.gov.uk/government/news/british-manufacturer-surescreen-diagnostics-to-supply-20-million-rapid-lateral-flow

  New tests will support the governments drive to deliver rapid testing to those without symptoms to break chains of transmission […] With up to a third of individuals with COVID-19 not displaying symptoms, broadening asymptomatic testing is essential in finding positive cases who may unknowingly pass on the virus in order to break chains of transmission. […] Rapid lateral flow tests strengthen our national response to the virus significantly, helping us to identify the around 1 in 3 people who are asymptomatic and break chains of transmission in our workplaces and communities. […] The kind of large-scale community testing that these tests facilitate is part of the governments COVID-19 winter plan to identify those who may be infectious with coronavirus earlier in order to break the chains of transmission and keep the virus under control.

• #55 Lateral flow test engineering and lessons learned from COVID-19 | Nature Reviews BioengineeringClose bannerClose banner

  https://www.nature.com/articles/s44222-022-00007-3

  COVID-19 antigen LFTs have sufficient accuracy for effective large-scale testing of SARS-CoV-2. […] The COVID-19 pandemic has revealed enormous inequities in access to tests, vaccines and therapeutics. […] The Access to COVID-19 Tools (ACT)-Accelerator diagnostic pillar (ACT-A Dx), part of the ACT-A mechanism, was established to increase equitable access to COVID-19 testing globally. […] Despite these efforts, of the 3 billion tests conducted worldwide by 2022, only 0.4% were used in low-income regions, which comprise 7.8% of the global population. […] The COVID-19 pandemic has reduced public access to care, and antimicrobial prescribing and childhood immunizations have decreased. […] The pandemic’s true impact on global antimicrobial resistance is yet to be confirmed, and new surveillance data must be gathered to update national strategies. […] The COVID-19 pandemic has affected the approach of regulators with regard to approving lateral flow tests (LFTs), including early engagement with and guidance to test developers.

• #56 Lateral flow test engineering and lessons learned from COVID-19 | Nature Reviews BioengineeringClose bannerClose banner

  https://www.nature.com/articles/s44222-022-00007-3

  Lateral flow tests (LFTs) were adopted at an unprecedented scale during the COVID-19 pandemic, enabling access to testing beyond healthcare settings. […] Key barriers to COVID-19 LFT development and adoption include lack of access to well characterized samples, limited accuracy, lack of connectivity, lack of evidence of cost-effectiveness, regulatory delays and centralized manufacturing capabilities. […] The accuracy and, in particular, the sensitivity of LFTs is lower than that of reference RT-PCR methods, ranging between 34.1% and 88.1% for SARS-CoV-2 antigen LFTs, with an overall specificity of 99.6%. […] The success of COVID-19 antigen LFTs can be in part attributed to the pathophysiology of SARS-CoV-2, that is, its short incubation period and high transmission rates, which are well suited to rapid, frequent testing.

• #57 Azthena logo with the word Azthena

  https://www.news-medical.net/news/20230123/Review-on-lateral-flow-test-use-spearheaded-by-SARS-CoV-2-pandemic.aspx

  Major roadblocks in LFT development and use include the lack of accessibility to well-characterized samples for testing and validation, low sensitivity, limited digital connectivity, scarce cost-efficacy evidence, delays in regulatory processes, and centralized manufacture of materials. […] Observations from the pandemic have shown that LFT self-testing at a large scale could offer several benefits, such as early identification and prompt self-isolation, increased accessibility to diagnostic tests, increased frequency of testing, increased compliance with public health measures, curtailed viral transmission, and facilitated early recovery. […] However, incorporating bioengineering approaches, machine learning, digitization, and multiplexing would require global collaborative efforts, regulatory harmonization, and an increase in funding to improve research infrastructure and increase the availability of suitable reagents. […] Efforts must be made to overcome LFT shortcomings, such as high false-negative rates, to provide next-generation diagnostic LFTs, with an equitable distribution, across the globe, to improve global preparedness against pathogens.

• #58 Azthena logo with the word Azthena

  https://www.news-medical.net/news/20230123/Review-on-lateral-flow-test-use-spearheaded-by-SARS-CoV-2-pandemic.aspx

  Major roadblocks in LFT development and use include the lack of accessibility to well-characterized samples for testing and validation, low sensitivity, limited digital connectivity, scarce cost-efficacy evidence, delays in regulatory processes, and centralized manufacture of materials. […] Observations from the pandemic have shown that LFT self-testing at a large scale could offer several benefits, such as early identification and prompt self-isolation, increased accessibility to diagnostic tests, increased frequency of testing, increased compliance with public health measures, curtailed viral transmission, and facilitated early recovery. […] However, incorporating bioengineering approaches, machine learning, digitization, and multiplexing would require global collaborative efforts, regulatory harmonization, and an increase in funding to improve research infrastructure and increase the availability of suitable reagents. […] Efforts must be made to overcome LFT shortcomings, such as high false-negative rates, to provide next-generation diagnostic LFTs, with an equitable distribution, across the globe, to improve global preparedness against pathogens.

• #59 Azthena logo with the word Azthena

  https://www.news-medical.net/news/20230123/Review-on-lateral-flow-test-use-spearheaded-by-SARS-CoV-2-pandemic.aspx

  LFT feasibility and acceptability for large-scale SARS-CoV-2 testing to improve population health have been observed during the coronavirus disease 2019 (COVID-19) pandemic. […] In the present review, researchers described the evolution of LFT testing, the advantages and disadvantages of LFTs, and identified roadblocks in developing next-generation LFTs based on the lessons learnt from the COVID-19 pandemic. […] The COVID-19 period accelerated LFT development, during which cases of unknown-cause pneumonia were reported in Wuhan, genetic sequencing information was shared, and the World Health Organization (WHO) released interim guidelines on rapid antigen test usage. […] However, LFTs were used successfully during COVID-19 due to the high SARS-CoV-2 transmissibility and short incubation periods to assess the infectiousness or transmission risks of SARS-CoV-2.

• #60 Recent Advances in Quantum Dot-Based Lateral Flow Immunoassays for the Rapid, Point-of-Care Diagnosis of COVID-19

  https://www.mdpi.com/2079-6374/13/8/786

  Quantum dot (QD)-based lateral flow immunoassays have emerged as a promising alternative, offering significant advancements in sensitivity and specificity. […] Moreover, the lateral flow immunoassay (LFIA) method, which fulfills POCT standards, has gained popularity in diagnosing COVID-19. […] This review focuses on recent advancements in QD-based LFIA for rapid POCT COVID-19 diagnosis. […] The benefits of using the QD-based LFIA as a POCT method are highlighted, and its published performance in COVID-19 diagnostics is examined. […] Overall, the integration of quantum dots with LFIA holds immense promise in terms of revolutionizing COVID-19 detection, treatment, and prevention, offering a convenient and effective approach to combat the pandemic. […] The S/N protein, also known as the spike protein, plays a crucial role in detecting COVID-19.

• #61 Enhancing a SARS-CoV-2 nucleocapsid antigen test sensitivity with cost efficient strategy through a cotton intermembrane insertion | Scientific Reports

  https://www.nature.com/articles/s41598-023-31641-5

  Lateral flow antigen tests have been widely used in the Covid-19 pandemic, allowing faster diagnostic test results and preventing further viral spread through isolation of infected individuals. […] The aim of this study was to create a lateral flow test that could detect SARS-CoV-2 nucleocapsid protein in low concentrations that were comparable to the limits of detection claimed by existing tests from the market. […] In order to guarantee good management of the viral spread in COVID-19, rapid tests used for screening must show good sensitivity for detection of SARS-CoV-2 N protein, avoiding false negatives and providing correct information about infection status. […] Clinical sensitivity performance of several SARS-CoV-2 N antigen diagnostic tests commercially available in Brazil were compared in a recent paper published by Freire et al., in which the authors described the sensitivity variation in a range from 9.8 to 81.1%.

• #62 Enhancing a SARS-CoV-2 nucleocapsid antigen test sensitivity with cost efficient strategy through a cotton intermembrane insertion | Scientific Reports

  https://www.nature.com/articles/s41598-023-31641-5

  The establishment of the lowest possible limit of detection is also extremely important when developing a SARS-CoV-2 antigen test, since isolation of the patients is highly dependent on antigen test positivity, when transmissibility is much more probable. […] Antigen tests with optimized limits of detection also tend to be more reliable in guaranteeing that viral load is below an infectiousness threshold when taking the decision to end the isolation period. […] The 2.0 ng mL1 LoD established for the test prototype in this work is comparable and even superior to most rapid tests for detection of SARS-CoV-2 antigen found on the market, making it an efficient and affordable solution for COVID-19 viral spread containment and decision making in patients isolation.

• #63 Enhancing a SARS-CoV-2 nucleocapsid antigen test sensitivity with cost efficient strategy through a cotton intermembrane insertion | Scientific Reports

  https://www.nature.com/articles/s41598-023-31641-5

  The establishment of the lowest possible limit of detection is also extremely important when developing a SARS-CoV-2 antigen test, since isolation of the patients is highly dependent on antigen test positivity, when transmissibility is much more probable. […] Antigen tests with optimized limits of detection also tend to be more reliable in guaranteeing that viral load is below an infectiousness threshold when taking the decision to end the isolation period. […] The 2.0 ng mL1 LoD established for the test prototype in this work is comparable and even superior to most rapid tests for detection of SARS-CoV-2 antigen found on the market, making it an efficient and affordable solution for COVID-19 viral spread containment and decision making in patients isolation.

• #64 Azthena logo with the word Azthena

  https://www.news-medical.net/news/20230123/Review-on-lateral-flow-test-use-spearheaded-by-SARS-CoV-2-pandemic.aspx

  Major roadblocks in LFT development and use include the lack of accessibility to well-characterized samples for testing and validation, low sensitivity, limited digital connectivity, scarce cost-efficacy evidence, delays in regulatory processes, and centralized manufacture of materials. […] Observations from the pandemic have shown that LFT self-testing at a large scale could offer several benefits, such as early identification and prompt self-isolation, increased accessibility to diagnostic tests, increased frequency of testing, increased compliance with public health measures, curtailed viral transmission, and facilitated early recovery. […] However, incorporating bioengineering approaches, machine learning, digitization, and multiplexing would require global collaborative efforts, regulatory harmonization, and an increase in funding to improve research infrastructure and increase the availability of suitable reagents. […] Efforts must be made to overcome LFT shortcomings, such as high false-negative rates, to provide next-generation diagnostic LFTs, with an equitable distribution, across the globe, to improve global preparedness against pathogens.

• #65 Azthena logo with the word Azthena

  https://www.news-medical.net/news/20230123/Review-on-lateral-flow-test-use-spearheaded-by-SARS-CoV-2-pandemic.aspx

  Major roadblocks in LFT development and use include the lack of accessibility to well-characterized samples for testing and validation, low sensitivity, limited digital connectivity, scarce cost-efficacy evidence, delays in regulatory processes, and centralized manufacture of materials. […] Observations from the pandemic have shown that LFT self-testing at a large scale could offer several benefits, such as early identification and prompt self-isolation, increased accessibility to diagnostic tests, increased frequency of testing, increased compliance with public health measures, curtailed viral transmission, and facilitated early recovery. […] However, incorporating bioengineering approaches, machine learning, digitization, and multiplexing would require global collaborative efforts, regulatory harmonization, and an increase in funding to improve research infrastructure and increase the availability of suitable reagents. […] Efforts must be made to overcome LFT shortcomings, such as high false-negative rates, to provide next-generation diagnostic LFTs, with an equitable distribution, across the globe, to improve global preparedness against pathogens.

• #66 Azthena logo with the word Azthena

  https://www.news-medical.net/news/20230123/Review-on-lateral-flow-test-use-spearheaded-by-SARS-CoV-2-pandemic.aspx

  Major roadblocks in LFT development and use include the lack of accessibility to well-characterized samples for testing and validation, low sensitivity, limited digital connectivity, scarce cost-efficacy evidence, delays in regulatory processes, and centralized manufacture of materials. […] Observations from the pandemic have shown that LFT self-testing at a large scale could offer several benefits, such as early identification and prompt self-isolation, increased accessibility to diagnostic tests, increased frequency of testing, increased compliance with public health measures, curtailed viral transmission, and facilitated early recovery. […] However, incorporating bioengineering approaches, machine learning, digitization, and multiplexing would require global collaborative efforts, regulatory harmonization, and an increase in funding to improve research infrastructure and increase the availability of suitable reagents. […] Efforts must be made to overcome LFT shortcomings, such as high false-negative rates, to provide next-generation diagnostic LFTs, with an equitable distribution, across the globe, to improve global preparedness against pathogens.

• #67 Azthena logo with the word Azthena

  https://www.news-medical.net/news/20230123/Review-on-lateral-flow-test-use-spearheaded-by-SARS-CoV-2-pandemic.aspx

  Major roadblocks in LFT development and use include the lack of accessibility to well-characterized samples for testing and validation, low sensitivity, limited digital connectivity, scarce cost-efficacy evidence, delays in regulatory processes, and centralized manufacture of materials. […] Observations from the pandemic have shown that LFT self-testing at a large scale could offer several benefits, such as early identification and prompt self-isolation, increased accessibility to diagnostic tests, increased frequency of testing, increased compliance with public health measures, curtailed viral transmission, and facilitated early recovery. […] However, incorporating bioengineering approaches, machine learning, digitization, and multiplexing would require global collaborative efforts, regulatory harmonization, and an increase in funding to improve research infrastructure and increase the availability of suitable reagents. […] Efforts must be made to overcome LFT shortcomings, such as high false-negative rates, to provide next-generation diagnostic LFTs, with an equitable distribution, across the globe, to improve global preparedness against pathogens.

• #68 Development and Efficacy of Lateral Flow Point-of-Care Testing Devices for Rapid and Mass COVID-19 Diagnosis by the Detections of SARS-CoV-2 Antigen and Anti-SARS-CoV-2 Antibodies

  https://pmc.ncbi.nlm.nih.gov/articles/PMC8534532/

  A commercial ELISA using the spike protein demonstrated that IgG antibodies were detectable at a median of 14 days after onset of symptoms. […] The study reported by Prez-Garca showed that the AllTest LFIA is a reliable complement of PCR to diagnose SARS-CoV-2 infection 14 days after the onset of symptoms in patients with pneumonia or patients with negative qRT-PCR for SARS-CoV-2. […] The outbreak of SARS-CoV-2 provides an opportunity for research and development in various techniques and methods for the COVID-19 diagnosis all around the globe. […] The aim is to develop accurate, rapid, and reliable detection techniques that can be distributed on a global scale to control the COVID-19 pandemic.

• #69 COVID-19 rapid antigen test – Wikipedia

  https://en.wikipedia.org/wiki/COVID-19_rapid_antigen_test

  COVID-19 rapid antigen tests or RATs, also frequently called COVID-19 lateral flow tests or LFTs, are rapid antigen tests used to detect SARS-CoV-2 infection (COVID-19). […] False positives are very rare; the tests’ specificity is 98%-99%. However, the tests have a sensitivity of 70%-72%, which is lower than COVID-19 polymerase chain reaction (PCR) tests’ sensitivity of 88%-96%. […] Despite this, COVID-19 RATs remain valuable in finding people who would otherwise not know they were infected, helping to prevent further transmission. The tests are more sensitive in the symptomatic and transmissive stages of disease when the viral load is higher. […] COVID-19 rapid antigen tests (RATs) have been widely used for diagnosis of COVID-19. […] Nevertheless, individual countries may have different case definitions of COVID-19; for example, in New Zealand a positive PCR test (not just a RAT) is necessary for a person to be considered a „confirmed case.”

• #70 How accurate are rapid antigen tests for diagnosing COVID-19? | Cochrane

  https://www.cochrane.org/CD013705/INFECTN_how-accurate-are-rapid-antigen-tests-diagnosing-covid-19

  Tests were most accurate when used in the first week after symptoms began (an average of 82% of confirmed cases had positive antigen tests). […] For people with no symptoms, tests were most accurate in people likely to have been in contact with a case of COVID-19 infection (an average of 64% of confirmed cases had positive antigen tests). […] Different brands of tests varied in accuracy. […] No test met this standard when evaluated in people without symptoms. […] Rapid antigen tests are less accurate when used in people with no symptoms of COVID-19. […] More evidence is needed to understand the accuracy of rapid testing in people without symptoms and the extent to which repeated testing strategies can lead to reduced transmission. […] Antigen tests vary in sensitivity. […] In people with signs and symptoms of COVID-19, sensitivities are highest in the first week of illness when viral loads are higher.

• #71 How likely is a positive COVID-19 lateral flow test to be wrong?verifiedverifiedverifiedverifiedverifiedverified

  https://www.gavi.org/vaccineswork/how-likely-positive-lateral-flow-test-covid-19-be-wrong

  However, if you get a positive test result, you can be more confident that you really are infected. This is because the specificity of LFTs – their ability to accurately diagnose uninfected individuals – is higher, and therefore false positives are highly unlikely. […] Even though LFTs are less sensitive than PCR, the Cochrane Review found that they were most accurate when used during the first week after symptoms developed (when 78% of confirmed cases recorded a positive LFT result). This is most likely because people have more virus in their bodies at this time.

• #72 How reliable are lateral flow COVID-19 tests? – The Pharmaceutical Journal

  https://pharmaceutical-journal.com/article/feature/how-reliable-are-lateral-flow-covid-19-tests

  It is estimated that around one-third of people with COVID-19 do not have symptoms and could be spreading the virus unknowingly. […] The target of the lateral flow test is proteins, or antigens, found in the COVID-19 virus. […] If you get a positive result from a lateral flow test, it is extremely likely you are currently infected with COVID-19 and risk infecting others. […] The MHRA has stated that “no test is 100% reliable”, even those that meet regulatory standards for performance and safety. […] This is because, unlike PCR tests, lateral flow tests cannot detect very low levels of coronavirus in a sample. […] The accuracy of lateral flow tests is also dependent on the person who does the test. […] A Cochrane review, published on 24 March 2021, investigated whether commercially available, rapid point-of-care antigen (lateral flow) and molecular tests were accurate enough to diagnose COVID-19 infection reliably.

• #73 Azthena logo with the word Azthena

  https://www.news-medical.net/news/20230123/Review-on-lateral-flow-test-use-spearheaded-by-SARS-CoV-2-pandemic.aspx

  Major roadblocks in LFT development and use include the lack of accessibility to well-characterized samples for testing and validation, low sensitivity, limited digital connectivity, scarce cost-efficacy evidence, delays in regulatory processes, and centralized manufacture of materials. […] Observations from the pandemic have shown that LFT self-testing at a large scale could offer several benefits, such as early identification and prompt self-isolation, increased accessibility to diagnostic tests, increased frequency of testing, increased compliance with public health measures, curtailed viral transmission, and facilitated early recovery. […] However, incorporating bioengineering approaches, machine learning, digitization, and multiplexing would require global collaborative efforts, regulatory harmonization, and an increase in funding to improve research infrastructure and increase the availability of suitable reagents. […] Efforts must be made to overcome LFT shortcomings, such as high false-negative rates, to provide next-generation diagnostic LFTs, with an equitable distribution, across the globe, to improve global preparedness against pathogens.

• #74 COVID-19 Lateral Flow Test

  https://www.icliniq.com/articles/infectious-diseases/covid-19-lateral-flow-test

  The World Health Organization (WHO) and other international organizations have recommended individual testing, mass population testing, and subsequent contact tracing to stop the chain of transmission of the COVID-19 virus. Hence, to control the transmission of the virus, there is an urgent need for large-scale, accurate, affordable, and rapid diagnostic testing assays. Advanced research should focus on developing a testing kit that is accurate in diagnosing the infection. The compact and easy-to-use lateral flow devices require no specialist training or equipment and are suitable for mass testing.

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