Materiały źródłowe

• #1 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). […] The tests are more sensitive in the symptomatic and transmissive stages of disease when the viral load is higher. […] In the systematic reviews, the sensitivity was higher for symptomatic people (76%-82%) than for asymptomatic people (57%-68%). […] 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. […] A 2022 study followed 225 adults and children with COVID-19 over 15 days using PCR tests, viral cultures, and home RATs. It found that the sensitivity of the RAT (Quidel QuickVue) increased from 0% two days prior to symptom onset or first positive PCR test to 77% four days after symptom onset or first positive PCR test, with an overall sensitivity of 50%. […] The sensitivity of the RAT was lower in persons who were vaccinated against COVID-19 than in persons who were not vaccinated against COVID-19.

• #1 COVID-19 symptoms and what to do – NHS

  https://www.nhs.uk/conditions/covid-19/covid-19-symptoms-and-what-to-do/

  COVID-19 symptoms can include: a high temperature or shivering (chills) a high temperature means you feel hot to touch on your chest or back (you do not need to measure your temperature) […] a new, continuous cough this means coughing a lot for more than an hour, or 3 or more coughing episodes in 24 hours […] a loss or change to your sense of smell or taste […] shortness of breath […] feeling tired or exhausted […] an aching body […] a headache […] a sore throat […] a blocked or runny nose […] loss of appetite […] diarrhoea […] feeling sick or being sick. […] Most people feel better within a few weeks, but it can take longer to recover. For some people, it can be a more serious illness and their symptoms can last longer. […] If you are eligible for treatments for COVID-19, you should take a rapid lateral flow test as soon as you get symptoms. […] You are no longer required to do a COVID-19 rapid lateral flow test if you have symptoms.

• #1 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

  Rapid antigen tests are most accurate when they are used in people who have signs or symptoms of COVID-19, especially during the first week of illness. People who test negative may still be infected. […] In people with confirmed COVID-19, antigen tests correctly identified COVID-19 infection in an average of 73% of people with symptoms, compared to 55% of people without symptoms. Tests were most accurate when used in the first week after symptoms began (an average of 82% of confirmed cases had positive antigen tests). […] 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, either for tests carried out at home or in non-healthcare settings such as schools. […] The variable sensitivity of antigen tests means that people who test negative may still be infected.

• #1 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. […] Lateral flow tests detect Covid-19 with similar accuracy to laboratory-based PCR tests, providing they are used at the onset of infection and soon after symptoms start. […] 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. […] In our study, both shorter duration of symptoms and higher viral load were significantly associated with a positive lateral flow tests. This highlights the necessity of testing at early infection with lateral flow tests, and shows that in patients who are newly symptomatic, the two testing methods have similar levels of accuracy. […] This study provides evidence that lateral flow tests can accurately detect SARS-CoV-2 infection as an alternative to PCR testing among symptomatic patients in a real-life primary care setting across a large geographical area.

• #1 Lateral Flow Tests Effective at Detecting COVID-19 When Used at Symptom Onset | Today’s Clinical Lab

  https://www.clinicallab.com/lateral-flow-tests-effective-at-detecting-covid-19-when-used-at-symptom-onset-25806

  In our study, both shorter duration of symptoms and higher viral load were significantly associated with positive lateral flow tests. This highlights the necessity of testing at early infection with lateral flow tests, and shows that in patients who are newly symptomatic, the two testing methods have similar levels of accuracy. […] This study provides evidence that lateral flow tests can accurately detect SARS-CoV-2 infection as an alternative to PCR testing among symptomatic patients in a real-life primary care setting across a large geographical area.

• #1 Does a faint line on a COVID-19 test mean I’m no longer infectious?verifiedverifiedverifiedverifiedverifiedverifiedverifiedverifiedverifiedverified

  https://www.gavi.org/vaccineswork/does-faint-line-covid-19-test-mean-im-no-longer-infectious

  Rapid antigen or lateral flow tests can help to identify when someone with COVID-19 is most infectious, but even a faint line should be treated as a positive result. […] Various studies have shown that people can have COVID-19 symptoms, and test positive on a PCR test, several days before a positive line can be seen on a rapid antigen test. This is because relatively large amounts of virus need to be present for the antibodies in the test to react to the viral proteins. A faint, slow-to-appear line could still represent high levels of virus, meaning that if you can see any line at all, you are still highly likely to be infectious. […] You should be particularly cautious if you see a faint line and believe you’re at the start of a COVID-19 infection, because viral load can rapidly increase during this time. However, if you can see any line at all, you are very likely to be infectious and should take steps to protect others.

• #1 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. […] 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. […] If you get a negative result from these self-tests, it means that the test has not been able to detect the COVID-19 virus in your sample. However, you may still be infectious, so you must still follow rules regarding social distancing and face coverings. […] The accuracy of lateral flow tests is also dependent on the person who does the test. […] Clinical evaluation carried out by Public Health England (PHE) and the University of Oxford at the end of 2020 showed that lateral flow tests were accurate enough to be used in the community, including for asymptomatic people, but that the tests performed best when levels of virus are at their highest and people are in the most infectious stage of the disease. […] They found that in people with confirmed COVID-19, antigen tests correctly identified COVID-19 infection in an average of 72% (ranging from 34% to 88%) of people with symptoms, compared with 58% of people without symptoms.

• #1 When should I use a rapid COVID test, and how accurate are they? | University of Chicago News

  https://news.uchicago.edu/story/when-should-i-use-rapid-covid-test-and-how-accurate-are-they

  Its still a good idea to isolate and get a COVID-19 test if you have any cold symptoms, even if theyre mild and even if youre fully vaccinated. Symptoms may include sniffles, congestion or a cough. COVID might resemble a mild cold, especially in fully vaccinated people. Know that even if you have minor symptoms, you are still contagious. […] If you have COVID-19 symptoms and test positive on an at-home test, you have COVID-19. You dont need to get another test to confirm the results. But if you have symptoms and you test negative, dont rule out COVID-19 just yet. In this case, get a more sensitive PCR test or repeat your home antigen test according to the manufacturers instructions (usually 48 hours after the first test). […] Given the widespread transmission of the Omicron variant, if you have symptoms, you should assume you are infected with COVID-19, regardless of your vaccination status. Isolate for the amount of time thats recommended by the health department.

• #1 Do At-Home COVID-19 Tests Still Work Well? | TIME

  https://time.com/7018565/do-at-home-covid-tests-still-work/

  These days, many people use at-home COVID-19 tests when they feel ill, rather than going out to get tested by a professional. […] Early in the pandemic, an infected person’s viral load—the amount of virus in their system—tended to peak around the time their symptoms began. […] Now that most everyone has prior immunity from multiple vaccines or infections, the timeline seems to be extended. Viral load now tends to peak around day four or five of symptoms, according to a study published in early 2024. […] A quicker immune response may mean a faster onset of symptoms. […] That immune response can show up as symptoms. […] Pollock and her co-authors estimated that a COVID-19 antigen test is somewhere between 30% and 60% accurate at detecting an infection on someone’s first day of symptoms, but up to 93% accurate on day four.

• #1 Do COVID-19 tests still work?verifiedverifiedverifiedverifiedverifiedverifiedverifiedverifiedverifiedverified

  https://www.gavi.org/vaccineswork/do-covid-19-tests-still-work

  This can create challenges if you’re relying on a COVID-19 test to predict whether you’re still likely to be infectious to other people. […] One possibility is that you genuinely don’t have COVID-19, and your symptoms are the result of influenza, RSV or some other respiratory virus instead. […] Even if you’ve been in close contact with someone with confirmed COVID-19, you could have caught a different virus from someone else – or even be infected with two viruses simultaneously – particularly when there are so many viruses circulating at once. […] Another possibility is that you haven’t collected your sample correctly or there isn’t yet enough virus to be detected using a lateral flow test. […] Rather than being directly caused by the pathogen, “disease symptoms are in large part mediated by an effective immune response, and because that immune response ignites very, very early during infection, it has anecdotally become quite common for people to report symptoms before their tests turn positive,” said Prof Joshua Schiffer, an infectious disease physician and researcher at the Fred Hutch Cancer Center in Seattle, US.

• #1 Do COVID-19 tests still work?verifiedverifiedverifiedverifiedverifiedverifiedverifiedverifiedverifiedverified

  https://www.gavi.org/vaccineswork/do-covid-19-tests-still-work

  Indeed, when Pollock and her colleagues investigated this possibility in 348 such individuals who caught COVID-19 between April 2022 and 2023, they found that their viral loads tended to peak around four days after the onset of symptoms. […] Referring to my own experience, Pollock said that it was also possible to have COVID-19 but to have a low SARS-CoV-2 viral load in the upper part of your throat. This means that it would remain under the threshold for a positive rapid test throughout the course of your symptoms. […] Schiffer warned that symptoms have never been a particularly good indicator of infectiousness for SARS-CoV-2, because they don’t necessarily correlate with the amount of virus in your body. […] Because of this variability, Schiffer warns against using a lateral flow test to definitively diagnose COVID-19 – particularly if you’re near the beginning of an infection: “If it’s negative, and you feel like you might have COVID-19, there’s a good chance it will return positive in the next few days – although there are so many other circulating viruses right now that you may well be contagious with something else.”

• #1

  https://pmc.ncbi.nlm.nih.gov/articles/PMC7374028/

  The mean time from the first day of symptoms to the antibody test was 28 days (SD: 8.7), similar according to the severity of the disease. […] The IgM response lasted longer in the severe critical cases (mean: 29.7 days; SD: 8.4) compared to the moderate cases (mean: 21.2 days; SD: 2.0). […] Rapid serology tests are useful for the diagnosis of patients with COVID-19 (mainly IgG detection) and may also be correlated with the severity of the infection (based on IgM detection). […] The average time from the first day of reported symptoms to the lateral flow test were 28 days (SD: 8.7). […] Among the 35 COVID-19 cases registered, 5 (14.3%) were clearly positive for both IgM and IgG bands, 21 (60%) were weakly positive for IgM and positive for IgG, and none were negative for both IgG and IgM.

• #1

  https://pmc.ncbi.nlm.nih.gov/articles/PMC7374028/

  Regarding the IgM band staining, the positive result was observed more frequently among the severe-critical cases (4; 11.4%) than in the mild-moderate ones (1; 2.9%). […] IgM response was more durable in severe-critical cases (mean: 29.7 days; SD: 8.4) as compared with moderate cases (mean: 21.2 days; SD: 2.0). […] In the case of the severe-critical cases, the weak positive IgM result appeared throughout the whole range of symptomatic days. […] For mild-moderate COVID-19 cases, positive IgG band appeared mostly around day 20 of symptoms (mean: 26.3 days; SD: 9.6).

• #1 COVID-19 – how long am I infectious and when can I safely leave isolation? | Imperial News | Imperial College London

  https://www.imperial.ac.uk/news/239212/covid-19-long-infectious-when-safely-leave/

  New research from Imperial College London scientists provides detailed new insights into how long people with COVID-19 are infectious. The study is the first real-world evidence of this kind. […] Based on our findings, we recommend that people with COVID-19 isolate for five days after symptoms begin, then use lateral flow tests to safely leave isolation. Dr Seran Hakki National Heart Lung Institute. […] Our study found that the average amount of time that people were infectious was five days. […] 22 of 34 people continued to shed infectious virus five days after their symptoms began, and eight of these people continued to shed infectious virus at seven days. […] Based on our findings, we recommend that people with COVID-19 isolate for five days after symptoms begin, then use lateral flow tests to safely leave isolation.

• #1 Using lateral flow tests to reduce the self-isolation period – UK Health Security Agency

  https://ukhsa.blog.gov.uk/2022/01/01/using-lateral-flow-tests-to-reduce-the-self-isolation-period/

  With COVID-19 cases reaching record levels across the UK, there is an increasing strain on key services, including the NHS. […] We recently advised that it is possible to reduce the self-isolation period for those with a confirmed diagnosis of COVID-19 from 10 days to 7, following two negative lateral flow tests taken on day 6 and day 7 after symptoms start (or, in the case of those who do not have any symptoms, from the date of their first positive test). […] After 10 days self-isolation, 5% of people will still be infectious. Ending self-isolation after 7 days and two negative LFD tests results in a similar level of protection. […] Our modelling suggests that 10-30% of people will potentially still remain infectious on day 6, if no re-assurance tests are performed at this point. […] We believe that allowing people to leave self-isolation after two negative lateral flow tests on days 6 and 7 is the optimal approach at present.

• #1 COVID-19 testing – NHS

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

  A rapid lateral flow test is done to check if you have COVID-19. […] If you’re eligible for COVID-19 treatments, you’ll need to take a COVID-19 rapid lateral flow test if you have any symptoms of 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 test positive for COVID-19, try to stay home and avoid meeting people for: 3 days after the day the test was taken if you’re under 18 years – children and young people tend to be infectious for less time than adults; 5 days after the day you took your test if you’re aged 18 or over. […] If you test negative and you’re eligible for COVID-19 treatments, you need to do a total of 3 rapid lateral flow tests over 3 days (1 test a day) if you continue to have COVID-19 symptoms.

• #1 A guide to COVID-19 tests for the public

  https://www.rcpath.org/profession/coronavirus-resource-hub/guide-to-covid-19-tests-for-members-of-the-public.html

  Patients with COVID-19 usually start to become positive by PCR testing a day or two before symptoms start and will continue to test positive by PCR afterwards for some time. […] People with symptoms need a PCR test. Lateral flow tests are intended for picking up additional infected cases who would otherwise be missed because they don’t have any symptoms. […] These tests are not as sensitive as PCR. They are simply a convenient way of picking up a proportion of undiagnosed people who have no symptoms. […] If a person tests positive with these tests, they need to confirm this by having a more accurate PCR. In the meantime, they must self-isolate. […] A negative lateral flow test should not be used to rule out infection or indicate that it is safe to do something such as visit relatives.

• #1 COVID-19: When should you do a lateral flow test and when should you do a PCR?

  https://patient.info/news-and-features/covid-19-when-should-you-do-a-lateral-flow-test-and-when-should-you-do-a-pcr

  Rapid lateral flow tests give a quick result and can be done at home. Current guidance recommends that these should be used only by people without symptoms. […] People are being advised to take PCR tests if they are experiencing symptoms of COVID-19, such as a high temperature, a new, continuous cough or a loss of smell or taste. […] You should do a PCR test as soon as possible if you have any of the three symptoms mentioned above. It’s important to do a test even if the symptoms are mild.

• #1 Coronavirus health advice – Haverhill Family Practice

  https://www.haverhillfamilypractice.co.uk/coronavirus-health-advice

  The lateral flow test is for people WITHOUT coronavirus symptoms (also called a rapid lateral flow test) […] DO NOT use a rapid flow test to try to self-diagnose (or rule out) COVID-19 infection if you have symptoms (e.g. high fever, cough, loss of smell etc.). Rapid flow tests do not provide confirmation of COVID-19 infection (though they might suggest it), nor do they absolutely exclude COVID-19 infection in the presence of symptoms. […] You need to take a PCR-test if you: have any symptoms of COVID-19, or Your rapid lateral flow test is positive. […] No symptoms – rapid lateral flow test […] Symptoms, or a +ve lateral flow test – PCR test.

• #1 How Lateral Flow COVID-19 Tests Work: A Guide

  https://assure-test.com/how-lateral-flow-covid-19-tests-work-a-guide/

  Lateral flow COVID-19 tests are a valuable component in the public health response to the pandemic. Their ease of use and rapid results make them an effective tool for early detection and isolation of cases, thereby reducing transmission. […] A positive result typically shows two lines (test and control), while a negative result shows only the control line. […] Sensitivity: LFTs may have lower sensitivity compared to PCR tests, especially in asymptomatic individuals. […] Follow-Up: Positive results should be confirmed with a PCR test, and negative results should not override clinical judgment if symptoms persist.

• #1

  https://discovery.ucl.ac.uk/id/eprint/10132208/

  OBJECTIVES: To investigate public use of lateral flow test [LFT] or polymerase chain reaction [PCR] test when experiencing key COVID-19 symptoms. […] In people with key COVID-19 symptoms (high temperature, cough, loss of sense of taste or smell), we also describe uptake of testing, if any. […] 10% of respondents thought Government guidance stated that they should take an LFT if symptomatic, while 18% of people thought that should take a PCR test; 60% thought they should take both types of test (12% did not select either option). […] In people who were symptomatic, 32% reported taking a test to confirm whether they had COVID-19. Of these, 53% reported taking a PCR test and 44% reported taking an LFT. […] Despite Government guidance stating that anyone with key COVID-19 symptoms should complete a PCR test, a significant percentage of the population use LFT tests when symptomatic. Communications should emphasise the superiority of, and need for, PCR tests in people with symptoms.

• #1 Do members of the public think they should use lateral flow tests (LFT) or polymerase chain reaction (PCR) tests when they have COVID-19-like symptoms? The COVID-19 Rapid Survey of Adherence to Interventions and Responses study

  https://pmc.ncbi.nlm.nih.gov/articles/PMC8316130/

  This study aimed to investigate public use of lateral flow tests (LFT) and polymerase chain reaction (PCR) tests when experiencing key COVID-19 symptoms. […] In people with key COVID-19 symptoms (high temperature / fever; new, continuous cough; loss of sense of smell; loss of taste), we also describe the uptake of testing, if any. […] Despite Government guidance stating that anyone with key COVID-19 symptoms should complete a PCR test, a significant percentage of the population use LFT tests when symptomatic. […] Our findings suggest that intended and actual testing behaviours in the public are out of step with Government recommendations. […] The easy accessibility of LFTs, 30 min turnaround time, and lack of compulsion to formally register the test with the Government (and hence self-isolate if the result is positive) probably make LFTs a more attractive option than PCR for some people.

• #1 COVID Testing – COVID-19 Protocols

  https://covidprotocols.org/chapters/covid-testing/

  Prioritize testing people with symptoms suggesting acute infection (see Screening Questions and Common Symptoms). […] The standard of care for diagnostic testing symptomatic patients is PCR-based testing, as it has the best sensitivity and specificity. […] When PCR-based testing capacity is restricted, use of the antigen test can increase testing capacity as well as offer advantages in terms of more low-cost testing with short turnaround time. […] The Antigen Test is likely to be positive at the same period that a person is most infectious from about 2 days prior to the onset of symptoms to about 2-3 days after the onset. […] The RT-PCR test (and other NAATs) is more sensitive than antigen testing. On average, it can (but does not always) pick up cases earlier than even 3 or 4 days before the onset of symptoms or 10+ days after symptom onset.

• #1 Lateral flow tests 95% effective at detecting Covid at start of symptoms | The Independent

  https://www.independent.co.uk/news/uk/home-news/lateral-flow-covid-tests-symptoms-b1883817.html

  Lateral flow tests (LFT) are 95 per cent effective at detecting Covid-19 if used at the onset of infection and soon after symptoms start, according to a new study. […] But a new study that is the first to compare two forms of testing on the same group of people on a large scale has shown that LFTs and PCR tests have very similar levels of accuracy in spotting Covid, but only when symptoms first start. […] Study author Dr Werner Leber from Queen Mary University of London said: 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. […] But we have found that in patients who are newly symptomatic, the two testing methods have similar levels of accuracy.

• #1 Do members of the public think they should use lateral flow tests (LFT) or polymerase chain reaction (PCR) tests when they have COVID-19-like symptoms? The COVID-19 Rapid Survey of Adherence to Interventions and Responses study

  https://pmc.ncbi.nlm.nih.gov/articles/PMC8316130/

  If LFTs are used instead of PCR by symptomatic people who would otherwise have requested a PCR test, their lower sensitivity reduces the chances of an accurate diagnosis. […] Until then, good communication with the public emphasising the superiority of PCR tests when symptomatic remains important.

• #1 High false-negative rate limits value of rapid COVID tests for kids | CIDRAP

  https://www.cidrap.umn.edu/high-false-negative-rate-limits-value-rapid-covid-tests-kids

  The uncertainty about whether negative rapid antigen tests can be trusted as well as the similarity of COVID-19 symptoms and those caused by allergies or other common infectious diseases has caused confusion for parents trying to make decisions about school and other activities. […] Wroblewski recommends that parents of symptomatic children who receive a negative result from a rapid antigen test seek a PCR test for confirmation. […] However, if children test positive and have symptoms, they should be considered infected and kept home from school and other activities, Osterholm said. […] The important thing to understand is that rapid tests are not perfect, Wroblewski said. „If your child is asymptomatic and you’re using rapid antigen tests to identify those asymptomatic infections before they go to school, see grandparents, or get on a plane, you’re not going to eliminate the risk that someone is actually infected and might move to positive in the next 24 hours,” she said. „You’re mitigating the risk.”

• #1 Treatments for coronavirus (COVID-19) | nidirect

  https://www.nidirect.gov.uk/articles/treatments-coronavirus-covid-19

  If you have checked that you are eligible for COVID-19 treatment and you develop any symptoms of COVID-19, even if they are mild, you should test as soon as possible with a lateral flow test. […] If your test is positive, contact your GP or GP out of hours service, who can refer you to be assessed for a COVID-19 treatment. […] These additional treatments need to be given quickly after you get a positive lateral flow test result to be most effective. […] If your test result is negative, but you still have symptoms of COVID-19, you need to do a total of three rapid lateral flow tests over three days. […] If any of these lateral flow tests are positive, you can stop testing and follow the steps for a positive test result.

• #1 COVID Testing – COVID-19 Protocols

  https://covidprotocols.org/chapters/covid-testing/

  Newly symptomatic patients who have been vaccinated should still be tested, as breakthrough cases still do occur. […] Patients 90 days from initial illness with new symptoms of COVID-19 can be retested on a case-by-case basis. Reinfection is rare, but not impossible. […] Recurrence of symptoms along with reemergence of positive PCR testing (particularly in patients with weakened immune systems) can occur in the absence of true reinfection.

• #1 Lateral flow testing introduced for antenatal care | Hull University Teaching Hospitals NHS Trust

  https://www.hey.nhs.uk/news/2021/06/10/lateral-flow-testing-introduced-for-antenatal-care/

  People attending antenatal appointments and scans are being asked to start self-screening for Covid-19. […] The Government has recently made twice weekly rapid testing, also known as lateral flow testing, available to everybody, as up to 1 in 3 adults have Covid-19 without any symptoms but can still infect others. […] Pregnant women and their birth partners are advised to carry out the test twice a week during pregnancy for their own peace of mind, and to ensure any Covid infection is picked up early and managed. […] Proof of a negative test result should be brought to the antenatal clinic or scan appointment. Anyone returning a positive result must not attend the hospital, but should contact the appropriate department as soon as possible to cancel and reschedule their appointment, while following all other relevant NHS instruction on testing and self-isolation.

• #1 Lateral flow testing introduced for antenatal care | Hull University Teaching Hospitals NHS Trust

  https://www.hey.nhs.uk/news/2021/06/10/lateral-flow-testing-introduced-for-antenatal-care/

  In line with national guidance, all hospitals will be asking women and their support person to carry out a lateral flow test before coming to hospital for routine antenatal care. […] This will help us identify people who may be Covid positive and unaware of it, so that we can manage their care appropriately, but it should also prevent them attending hospital and so reduce the risk of transmission to others. […] At the same time, we know many people have had Covid-19 and shown no signs or symptoms, so completing a quick lateral flow test just prior to the appointment date is an easy way to show you care and reduce the risk for everyone.

• #1 Do At-Home COVID-19 Tests Still Work Well? | TIME

  https://time.com/7018565/do-at-home-covid-tests-still-work/

  Although it’s a hard sell for people who no longer take precautions, the ideal scenario is for someone to stay isolated—or at least wear a mask when around other people—and test again around day four of symptoms. […] If you’re symptomatic, you should test early. But if you’re negative, you need to repeat it, because the amount of virus in your nose may not be high enough yet to detect. […] If you have COVID-like symptoms but test negative, it’s best to be cautious and retest in a few days.

• #1 When To Use a Lateral Flow Test Now They’re Not free | ZOE

  https://zoe.com/learn/covid-end-of-free-testing

  Overall, our data suggest that its not worth doing another lateral flow test for at least 5 or 6 days after testing positive, as youre very unlikely to test negative before then and youll just be wasting your kits. […] If you test positive after this period, you should wait another day or two before you test again. […] Finally, remember that as long as you test positive, you may still be infectious and can pass the virus on to people.

• #1 When To Use a Lateral Flow Test Now They’re Not free | ZOE

  https://zoe.com/learn/covid-end-of-free-testing

  Our initial analysis of almost 100,000 test results reported in the ZOE app shows that home-based lateral flow tests (LFTs) are very good at detecting COVID-19. […] You should do an LFT on the first day you notice cold-like symptoms that might be COVID, such as a cough, runny nose, fever, headache or feeling very tired. […] When rates of COVID are high, these symptoms are more likely to be caused by COVID than a cold, so you should do a test to be sure. […] If you test positive, its recommended that you stay at home for at least five days, or until you feel well enough to carry on with your daily life. […] However, our analysis shows that it takes an average of 8 days after the first positive test for people to report a negative test. […] Interestingly, we also noticed a difference across age groups in how long it took for tests to turn negative again, with positive test results likely to persist longer in older people than in younger age groups.

• #1 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. […] If, after the instructed time has passed, any line is visible on the test line, the result is considered positive. The specificity of lateral flow tests is generally very high (meaning there is a small chance of false positive results). […] 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.

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

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

  The biggest factor, though, is the timing of the sample. For COVID-19 tests, if the sample is taken too early (before symptoms are present), or too late (beyond the first week of symptoms), a negative result may occur. In other words, receiving a negative result doesn’t mean you are free of infection.

• #1 Covid-19: MHRA is concerned over use of rapid lateral flow devices for mass testing | The BMJ

  https://www.bmj.com/content/373/bmj.n1090

  The UKs medicines regulator is understood to have raised concerns that the governments mass testing programme for covid-19 is a stretch of its authorisation for how rapid lateral flow tests should be used. […] Although the Medicines and Healthcare Products Regulatory Agency approved the Innova rapid lateral flow test to detect cases of SARS-CoV-2 infection at home, it has emphasised that negative results should not be used as a green light for people to change their behaviour and be less cautious. […] But experts have warned that empirical evidence was lacking to show that lateral flow devices were effective at detecting SARS-CoV-2 in asymptomatic people who tested themselves. […] A recently published Cochrane review found that the tests correctly identified an average of 58% of people who were infected, but the number of samples from asymptomatic people was around a 10th that from symptomatic people in the studies, limiting the conclusions that could be drawn.

• #1 Covid-19: MHRA is concerned over use of rapid lateral flow devices for mass testing | The BMJ

  https://www.bmj.com/content/373/bmj.n1090

  False positive results will be a problem when prevalence is low, even with PCR confirmation. And the temptation for people with symptoms to opt for unsupervised, rapid, and lower sensitivity self-testing may lead to false reassurance, as happens with other screening, leading to potential increases in transmission.

• #1 Rapid Tests | Department of Health

  https://www.health-ni.gov.uk/articles/rapid-tests

  Its recommended to use a Rapid Test twice per week. Regular testing helps to identify if you have COVID before it spreads to the people close to you. You should also take a test before attending any social gatherings. […] Yes it is still possible to catch and pass on COVID-19 following vaccination. Some people, including young children and those with health conditions, can’t be vaccinated yet. Regular Rapid Testing helps to keep them safe. […] No if you have COVID-19 symptoms you should book a PCR test.

• #1 Rapid Tests | Department of Health

  https://www.health-ni.gov.uk/articles/rapid-tests

  Anyone in Northern Ireland can access free Rapid Lateral Flow Tests to keep our friends, family and colleagues safe. Rapid Tests are quick, easy and convenient. They provide a result within 30 minutes at home. You should take a test before meeting friends and family, or attending an event or social gathering. Rapid Tests should only be used by people with no symptoms. If you have ANY symptoms of COVID-19, you should self-isolate and book a PCR test instead. Do you have: a high temperature; a new, continuous cough; or noticed a loss or change in your sense of smell? […] Rapid Testing twice a week is strongly recommended for anyone over the age of 11, particularly if you’re planning to mix with other people. Everyone, who does not have symptoms, should take a rapid lateral flow test before: meeting friends and family, attending an event or social gathering, spending time in a crowd or a busy public place, visiting someone who is elderly or more vulnerable.

• #2 The rise of the lateral flow test: everything you need to know about lateral flow tests in five steps – Una Health

  https://unahealth.co.uk/blog/the-rise-of-the-lateral-flow-test-everything-you-need-to-know-about-lateral-flow-tests-in-five-steps/

  Lateral flow tests are rapid diagnostic tests that may be used at the point-of-care (i.e., with a patient during a clinical consultation). […] When diagnosing an infection, there are two types of lateral flow test according to the molecule of interest that they detect. […] Antigen detection: these tests determine if a person is currently infected. […] Example: detection of the nucleocapsid protein of SARS-CoV-2 in the COVID-19 rapid antigen test from Fortress Diagnostics. […] Antibody detection: these tests usually indicate past exposure to an infectious agent (depending on the type of antibody detected: IgA, IgM or IgG). […] Example: detection of total antibody to SARS-CoV-2 spike protein in the COVID-19 rapid antibody test from Fortress Diagnostics. […] The COVID-19 pandemic saw a boom in the availability of lateral flow tests but we quickly learnt that not all lateral flow tests, and their evaluations, are created equally.

• #2 Coronavirus & COVID-19 Overview: Symptoms, Risks, Prevention, Treatment & More

  https://www.webmd.com/covid/coronavirus

  COVID-19 is a disease caused by SARS-CoV-2 that can trigger what doctors call a respiratory tract infection. The main symptoms include: Fever, Coughing, Shortness of breath, Trouble breathing, Fatigue, Chills, sometimes with shaking, Body aches, Headache, Sore throat, Congestion/runny nose, Loss of smell or taste, Nausea, Diarrhea. The virus can lead to pneumonia, respiratory failure, heart problems, liver problems, septic shock, and death. Many COVID-19 complications may be caused by a condition known as cytokine release syndrome or a cytokine storm. If you notice the following severe symptoms in yourself or a loved one, get medical help right away: Trouble breathing or shortness of breath, Ongoing chest pain or pressure, Confusion, Can’t wake up fully, Bluish lips or face. If you’re infected, symptoms can show up in as few as 2 days or as many as 14. It varies from person to person. According to researchers in China, these were the most common symptoms among people who had COVID-19: Fever 99%, Fatigue 70%, Cough 59%, Lack of appetite 40%, Body aches 35%, Shortness of breath 31%, Mucus/phlegm 27%. Some people who are hospitalized for COVID-19 also have dangerous blood clots, including in their legs, lungs, and arteries. Every case is different. You may have mild flu-like symptoms for a few days after exposure, then get better. But some cases can be severe or fatal. Symptoms can also linger for weeks, even if they’re mild. More than a third of people older than 18 who have signs of the virus aren’t totally recovered 2 or 3 weeks later, according to a CDC survey. Fatigue and cough were the symptoms that were most likely to linger. Some other people who’ve had COVID-19 develop a condition similar to myalgic encephalomyelitis, also known as chronic fatigue syndrome. They may have brain fog, severe fatigue, pain, trouble thinking, or dizziness.

• #2 Lateral Flow Tests Effective at Detecting COVID-19 When Used at Symptom Onset | Today’s Clinical Lab

  https://www.clinicallab.com/lateral-flow-tests-effective-at-detecting-covid-19-when-used-at-symptom-onset-25806

  A new study by researchers at Queen Mary University of London, University of Oxford, Institute for Advanced Studies, Vienna, and the Medical University of Graz, has found that lateral flow tests detect COVID-19 with similar accuracy to laboratory-based PCR tests, providing they are used at the onset of infection and soon after symptoms start. […] The lateral flow tests detected more than 95 percent of the cases found by PCR, and correctly identified 89 percent 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. But we have found that in patients who are newly symptomatic, the two testing methods have similar levels of accuracy.

• #2 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

  Rapid antigen tests are most accurate when they are used in people who have signs or symptoms of COVID-19, especially during the first week of illness. People who test negative may still be infected. […] In people with confirmed COVID-19, antigen tests correctly identified COVID-19 infection in an average of 73% of people with symptoms, compared to 55% of people without symptoms. Tests were most accurate when used in the first week after symptoms began (an average of 82% of confirmed cases had positive antigen tests). […] 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, either for tests carried out at home or in non-healthcare settings such as schools. […] The variable sensitivity of antigen tests means that people who test negative may still be infected.

• #2 Lateral flow tests are 95% effective at detecting Covid-19 when used at the onset of symptoms – Queen Mary University of London

  https://www.qmul.ac.uk/media/news/2021/smd/lateral-flow-tests-are-95-effective-at-detecting-covid-19-when-used-at-the-onset-of-symptoms.html

  Lateral flow tests are 95% effective at detecting Covid-19 when used at the onset of symptoms. A new study by researchers at Queen Mary University of London, University of Oxford, Institute for Advanced Studies, Vienna, and the Medical University of Graz, has found that lateral flow tests detect Covid-19 with similar accuracy to laboratory-based PCR tests, providing they are used at the onset of infection and soon after symptoms start. 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. But we have found that in patients who are newly symptomatic, the two testing methods have similar levels of accuracy. In our study, both shorter duration of symptoms and higher viral load were significantly associated with positive lateral flow tests. This highlights the necessity of testing at early infection with lateral flow tests, and shows that in patients who are newly symptomatic, the two testing methods have similar levels of accuracy. 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. In summary, this study provides evidence that lateral flow tests can accurately detect SARS-CoV-2 infection as an alternative to PCR testing among symptomatic patients in a real-life primary care setting across a large geographical area.

• #2 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. […] Lateral flow tests detect Covid-19 with similar accuracy to laboratory-based PCR tests, providing they are used at the onset of infection and soon after symptoms start. […] 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. […] In our study, both shorter duration of symptoms and higher viral load were significantly associated with a positive lateral flow tests. This highlights the necessity of testing at early infection with lateral flow tests, and shows that in patients who are newly symptomatic, the two testing methods have similar levels of accuracy. […] This study provides evidence that lateral flow tests can accurately detect SARS-CoV-2 infection as an alternative to PCR testing among symptomatic patients in a real-life primary care setting across a large geographical area.

• #2 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. […] 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. […] If you get a negative result from these self-tests, it means that the test has not been able to detect the COVID-19 virus in your sample. However, you may still be infectious, so you must still follow rules regarding social distancing and face coverings. […] The accuracy of lateral flow tests is also dependent on the person who does the test. […] Clinical evaluation carried out by Public Health England (PHE) and the University of Oxford at the end of 2020 showed that lateral flow tests were accurate enough to be used in the community, including for asymptomatic people, but that the tests performed best when levels of virus are at their highest and people are in the most infectious stage of the disease. […] They found that in people with confirmed COVID-19, antigen tests correctly identified COVID-19 infection in an average of 72% (ranging from 34% to 88%) of people with symptoms, compared with 58% of people without symptoms.

• #2 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. […] Two lines still mean positive, one line still means negative, and the safety precautions remain the same: „Five days of [isolation] and then five days of masking if you have no symptoms, before going back to your normal routine, Vail said. […] On day six, about 50 percent will still test positive. […] That uncertainty is why the CDC recommends five more days of isolation.

• #2 A guide to COVID-19 tests for the public

  https://www.rcpath.org/profession/coronavirus-resource-hub/guide-to-covid-19-tests-for-members-of-the-public.html

  Patients with COVID-19 usually start to become positive by PCR testing a day or two before symptoms start and will continue to test positive by PCR afterwards for some time. […] People with symptoms need a PCR test. Lateral flow tests are intended for picking up additional infected cases who would otherwise be missed because they don’t have any symptoms. […] These tests are not as sensitive as PCR. They are simply a convenient way of picking up a proportion of undiagnosed people who have no symptoms. […] If a person tests positive with these tests, they need to confirm this by having a more accurate PCR. In the meantime, they must self-isolate. […] A negative lateral flow test should not be used to rule out infection or indicate that it is safe to do something such as visit relatives.

• #2 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. […] The intended use of this test is for testing individuals within the first 5 days of symptom onset. […] All negative results are presumptive; symptomatic individuals with an initial negative test result must be re-tested once between 48 and 72 hours after the first test using either an antigen test or a molecular test for SARS-CoV-2. […] Individuals who test negative and experience continued or worsening COVID-19 like symptoms, such as fever, cough and/or shortness of breath, should seek follow up care from their healthcare provider.

• #2 Do COVID-19 tests still work?verifiedverifiedverifiedverifiedverifiedverifiedverifiedverifiedverifiedverified

  https://www.gavi.org/vaccineswork/do-covid-19-tests-still-work

  Indeed, when Pollock and her colleagues investigated this possibility in 348 such individuals who caught COVID-19 between April 2022 and 2023, they found that their viral loads tended to peak around four days after the onset of symptoms. […] Referring to my own experience, Pollock said that it was also possible to have COVID-19 but to have a low SARS-CoV-2 viral load in the upper part of your throat. This means that it would remain under the threshold for a positive rapid test throughout the course of your symptoms. […] Schiffer warned that symptoms have never been a particularly good indicator of infectiousness for SARS-CoV-2, because they don’t necessarily correlate with the amount of virus in your body. […] Because of this variability, Schiffer warns against using a lateral flow test to definitively diagnose COVID-19 – particularly if you’re near the beginning of an infection: “If it’s negative, and you feel like you might have COVID-19, there’s a good chance it will return positive in the next few days – although there are so many other circulating viruses right now that you may well be contagious with something else.”

• #2 Does a faint line on a COVID-19 test mean I’m no longer infectious?verifiedverifiedverifiedverifiedverifiedverifiedverifiedverifiedverifiedverified

  https://www.gavi.org/vaccineswork/does-faint-line-covid-19-test-mean-im-no-longer-infectious

  Some people continue to test positive on lateral flow tests for several weeks after developing symptoms. A recent Cochrane Review found that these tests were most accurate when used during the first week after COVID-19 symptoms developed. Other studies have indicated that most people remain contagious for four to eight days after developing symptoms – although these studies were done before the emergence of the Omicron variant and widespread vaccination against COVID-19. […] Current guidelines for time in isolation vary depending on the country and situation, but five days from the onset of symptoms, or a positive test result, should be regarded as the absolute minimum, because some people will remain infectious after that.

• #2 Do At-Home COVID-19 Tests Still Work Well? | TIME

  https://time.com/7018565/do-at-home-covid-tests-still-work/

  These days, many people use at-home COVID-19 tests when they feel ill, rather than going out to get tested by a professional. […] Early in the pandemic, an infected person’s viral load—the amount of virus in their system—tended to peak around the time their symptoms began. […] Now that most everyone has prior immunity from multiple vaccines or infections, the timeline seems to be extended. Viral load now tends to peak around day four or five of symptoms, according to a study published in early 2024. […] A quicker immune response may mean a faster onset of symptoms. […] That immune response can show up as symptoms. […] Pollock and her co-authors estimated that a COVID-19 antigen test is somewhere between 30% and 60% accurate at detecting an infection on someone’s first day of symptoms, but up to 93% accurate on day four.

• #2

  https://pmc.ncbi.nlm.nih.gov/articles/PMC7374028/

  Regarding the IgM band staining, the positive result was observed more frequently among the severe-critical cases (4; 11.4%) than in the mild-moderate ones (1; 2.9%). […] IgM response was more durable in severe-critical cases (mean: 29.7 days; SD: 8.4) as compared with moderate cases (mean: 21.2 days; SD: 2.0). […] In the case of the severe-critical cases, the weak positive IgM result appeared throughout the whole range of symptomatic days. […] For mild-moderate COVID-19 cases, positive IgG band appeared mostly around day 20 of symptoms (mean: 26.3 days; SD: 9.6).

• #2 Using lateral flow tests to reduce the self-isolation period – UK Health Security Agency

  https://ukhsa.blog.gov.uk/2022/01/01/using-lateral-flow-tests-to-reduce-the-self-isolation-period/

  With COVID-19 cases reaching record levels across the UK, there is an increasing strain on key services, including the NHS. […] We recently advised that it is possible to reduce the self-isolation period for those with a confirmed diagnosis of COVID-19 from 10 days to 7, following two negative lateral flow tests taken on day 6 and day 7 after symptoms start (or, in the case of those who do not have any symptoms, from the date of their first positive test). […] After 10 days self-isolation, 5% of people will still be infectious. Ending self-isolation after 7 days and two negative LFD tests results in a similar level of protection. […] Our modelling suggests that 10-30% of people will potentially still remain infectious on day 6, if no re-assurance tests are performed at this point. […] We believe that allowing people to leave self-isolation after two negative lateral flow tests on days 6 and 7 is the optimal approach at present.

• #2 COVID-19 – how long am I infectious and when can I safely leave isolation? | Imperial News | Imperial College London

  https://www.imperial.ac.uk/news/239212/covid-19-long-infectious-when-safely-leave/

  Our study found that, while lateral flow tests are not reliable for early diagnosis (unless used daily), they are good at spotting when someone is no longer infectious, so testing to release people from isolation may work. […] After five days of isolation, people can complete lateral flow tests on days six and seven. […] If these tests are negative, we think it is safe to leave isolation on day seven. […] Or, they can leave isolation on the 10th day after their symptoms began. Based on the evidence available, we think it’s unlikely for people to still be infectious on day 10.

• #2 COVID-19: When should you do a lateral flow test and when should you do a PCR?

  https://patient.info/news-and-features/covid-19-when-should-you-do-a-lateral-flow-test-and-when-should-you-do-a-pcr

  Rapid lateral flow tests give a quick result and can be done at home. Current guidance recommends that these should be used only by people without symptoms. […] People are being advised to take PCR tests if they are experiencing symptoms of COVID-19, such as a high temperature, a new, continuous cough or a loss of smell or taste. […] You should do a PCR test as soon as possible if you have any of the three symptoms mentioned above. It’s important to do a test even if the symptoms are mild.

• #2 Coronavirus health advice – Haverhill Family Practice

  https://www.haverhillfamilypractice.co.uk/coronavirus-health-advice

  The lateral flow test is for people WITHOUT coronavirus symptoms (also called a rapid lateral flow test) […] DO NOT use a rapid flow test to try to self-diagnose (or rule out) COVID-19 infection if you have symptoms (e.g. high fever, cough, loss of smell etc.). Rapid flow tests do not provide confirmation of COVID-19 infection (though they might suggest it), nor do they absolutely exclude COVID-19 infection in the presence of symptoms. […] You need to take a PCR-test if you: have any symptoms of COVID-19, or Your rapid lateral flow test is positive. […] No symptoms – rapid lateral flow test […] Symptoms, or a +ve lateral flow test – PCR test.

• #2 PCR Test needed if you have COVID-19 Symptoms – Stockport Medical Group

  https://www.stockportmedicalgroup.nhs.uk/pcr-test-needed-if-you-have-covid-19-symptoms/

  If you have any ONE or more of the above symptoms, we will ask for a PCR test to be taken prior to making you a face to face appointment with the GP. […] When you have symptoms a Lateral Flow Test is not sufficient to rule out COVID-19, this can only be confirmed by a negative PCR test. […] Rapid Lateral Flow tests are only for people who do not have symptoms, they give a quick result using a device similar to a pregnancy test. […] 1 in 3 people with COVID-19 do not have symptoms but can infect others, even if you’re vaccinated, you could still catch the virus or pass it on. […] If you have symptoms, self-isolate straight away until you get your results. Do not leave home, except to post a test kit or for a PCR test appointment. […] You need to get the test done in the first 8 days of having symptoms.

• #2 Rapid Tests | Department of Health

  https://www.health-ni.gov.uk/articles/rapid-tests

  Anyone in Northern Ireland can access free Rapid Lateral Flow Tests to keep our friends, family and colleagues safe. Rapid Tests are quick, easy and convenient. They provide a result within 30 minutes at home. You should take a test before meeting friends and family, or attending an event or social gathering. Rapid Tests should only be used by people with no symptoms. If you have ANY symptoms of COVID-19, you should self-isolate and book a PCR test instead. Do you have: a high temperature; a new, continuous cough; or noticed a loss or change in your sense of smell? […] Rapid Testing twice a week is strongly recommended for anyone over the age of 11, particularly if you’re planning to mix with other people. Everyone, who does not have symptoms, should take a rapid lateral flow test before: meeting friends and family, attending an event or social gathering, spending time in a crowd or a busy public place, visiting someone who is elderly or more vulnerable.

• #2 Do members of the public think they should use lateral flow tests (LFT) or polymerase chain reaction (PCR) tests when they have COVID-19-like symptoms? The COVID-19 Rapid Survey of Adherence to Interventions and Responses study

  https://pmc.ncbi.nlm.nih.gov/articles/PMC8316130/

  This study aimed to investigate public use of lateral flow tests (LFT) and polymerase chain reaction (PCR) tests when experiencing key COVID-19 symptoms. […] In people with key COVID-19 symptoms (high temperature / fever; new, continuous cough; loss of sense of smell; loss of taste), we also describe the uptake of testing, if any. […] Despite Government guidance stating that anyone with key COVID-19 symptoms should complete a PCR test, a significant percentage of the population use LFT tests when symptomatic. […] Our findings suggest that intended and actual testing behaviours in the public are out of step with Government recommendations. […] The easy accessibility of LFTs, 30 min turnaround time, and lack of compulsion to formally register the test with the Government (and hence self-isolate if the result is positive) probably make LFTs a more attractive option than PCR for some people.

• #2 COVID Testing – COVID-19 Protocols

  https://covidprotocols.org/chapters/covid-testing/

  Prioritize testing people with symptoms suggesting acute infection (see Screening Questions and Common Symptoms). […] The standard of care for diagnostic testing symptomatic patients is PCR-based testing, as it has the best sensitivity and specificity. […] When PCR-based testing capacity is restricted, use of the antigen test can increase testing capacity as well as offer advantages in terms of more low-cost testing with short turnaround time. […] The Antigen Test is likely to be positive at the same period that a person is most infectious from about 2 days prior to the onset of symptoms to about 2-3 days after the onset. […] The RT-PCR test (and other NAATs) is more sensitive than antigen testing. On average, it can (but does not always) pick up cases earlier than even 3 or 4 days before the onset of symptoms or 10+ days after symptom onset.

• #2 High false-negative rate limits value of rapid COVID tests for kids | CIDRAP

  https://www.cidrap.umn.edu/high-false-negative-rate-limits-value-rapid-covid-tests-kids

  The uncertainty about whether negative rapid antigen tests can be trusted as well as the similarity of COVID-19 symptoms and those caused by allergies or other common infectious diseases has caused confusion for parents trying to make decisions about school and other activities. […] Wroblewski recommends that parents of symptomatic children who receive a negative result from a rapid antigen test seek a PCR test for confirmation. […] However, if children test positive and have symptoms, they should be considered infected and kept home from school and other activities, Osterholm said. […] The important thing to understand is that rapid tests are not perfect, Wroblewski said. „If your child is asymptomatic and you’re using rapid antigen tests to identify those asymptomatic infections before they go to school, see grandparents, or get on a plane, you’re not going to eliminate the risk that someone is actually infected and might move to positive in the next 24 hours,” she said. „You’re mitigating the risk.”

• #2 Do At-Home COVID-19 Tests Still Work Well? | TIME

  https://time.com/7018565/do-at-home-covid-tests-still-work/

  Although it’s a hard sell for people who no longer take precautions, the ideal scenario is for someone to stay isolated—or at least wear a mask when around other people—and test again around day four of symptoms. […] If you’re symptomatic, you should test early. But if you’re negative, you need to repeat it, because the amount of virus in your nose may not be high enough yet to detect. […] If you have COVID-like symptoms but test negative, it’s best to be cautious and retest in a few days.

• #2 COVID-19 testing – NHS

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

  A rapid lateral flow test is done to check if you have COVID-19. […] If you’re eligible for COVID-19 treatments, you’ll need to take a COVID-19 rapid lateral flow test if you have any symptoms of 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 test positive for COVID-19, try to stay home and avoid meeting people for: 3 days after the day the test was taken if you’re under 18 years – children and young people tend to be infectious for less time than adults; 5 days after the day you took your test if you’re aged 18 or over. […] If you test negative and you’re eligible for COVID-19 treatments, you need to do a total of 3 rapid lateral flow tests over 3 days (1 test a day) if you continue to have COVID-19 symptoms.

• #2 COVID-19 symptoms and what to do – NHS

  https://www.nhs.uk/conditions/covid-19/covid-19-symptoms-and-what-to-do/

  COVID-19 symptoms can include: a high temperature or shivering (chills) a high temperature means you feel hot to touch on your chest or back (you do not need to measure your temperature) […] a new, continuous cough this means coughing a lot for more than an hour, or 3 or more coughing episodes in 24 hours […] a loss or change to your sense of smell or taste […] shortness of breath […] feeling tired or exhausted […] an aching body […] a headache […] a sore throat […] a blocked or runny nose […] loss of appetite […] diarrhoea […] feeling sick or being sick. […] Most people feel better within a few weeks, but it can take longer to recover. For some people, it can be a more serious illness and their symptoms can last longer. […] If you are eligible for treatments for COVID-19, you should take a rapid lateral flow test as soon as you get symptoms. […] You are no longer required to do a COVID-19 rapid lateral flow test if you have symptoms.

• #2 Lateral flow testing introduced for antenatal care | Hull University Teaching Hospitals NHS Trust

  https://www.hey.nhs.uk/news/2021/06/10/lateral-flow-testing-introduced-for-antenatal-care/

  People attending antenatal appointments and scans are being asked to start self-screening for Covid-19. […] The Government has recently made twice weekly rapid testing, also known as lateral flow testing, available to everybody, as up to 1 in 3 adults have Covid-19 without any symptoms but can still infect others. […] Pregnant women and their birth partners are advised to carry out the test twice a week during pregnancy for their own peace of mind, and to ensure any Covid infection is picked up early and managed. […] Proof of a negative test result should be brought to the antenatal clinic or scan appointment. Anyone returning a positive result must not attend the hospital, but should contact the appropriate department as soon as possible to cancel and reschedule their appointment, while following all other relevant NHS instruction on testing and self-isolation.

• #2 Lateral flow testing introduced for antenatal care | Hull University Teaching Hospitals NHS Trust

  https://www.hey.nhs.uk/news/2021/06/10/lateral-flow-testing-introduced-for-antenatal-care/

  In line with national guidance, all hospitals will be asking women and their support person to carry out a lateral flow test before coming to hospital for routine antenatal care. […] This will help us identify people who may be Covid positive and unaware of it, so that we can manage their care appropriately, but it should also prevent them attending hospital and so reduce the risk of transmission to others. […] At the same time, we know many people have had Covid-19 and shown no signs or symptoms, so completing a quick lateral flow test just prior to the appointment date is an easy way to show you care and reduce the risk for everyone.

• #2 When To Use a Lateral Flow Test Now They’re Not free | ZOE

  https://zoe.com/learn/covid-end-of-free-testing

  Our initial analysis of almost 100,000 test results reported in the ZOE app shows that home-based lateral flow tests (LFTs) are very good at detecting COVID-19. […] You should do an LFT on the first day you notice cold-like symptoms that might be COVID, such as a cough, runny nose, fever, headache or feeling very tired. […] When rates of COVID are high, these symptoms are more likely to be caused by COVID than a cold, so you should do a test to be sure. […] If you test positive, its recommended that you stay at home for at least five days, or until you feel well enough to carry on with your daily life. […] However, our analysis shows that it takes an average of 8 days after the first positive test for people to report a negative test. […] Interestingly, we also noticed a difference across age groups in how long it took for tests to turn negative again, with positive test results likely to persist longer in older people than in younger age groups.

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

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

  The biggest factor, though, is the timing of the sample. For COVID-19 tests, if the sample is taken too early (before symptoms are present), or too late (beyond the first week of symptoms), a negative result may occur. In other words, receiving a negative result doesn’t mean you are free of infection.

• #2 Covid-19: MHRA is concerned over use of rapid lateral flow devices for mass testing | The BMJ

  https://www.bmj.com/content/373/bmj.n1090

  False positive results will be a problem when prevalence is low, even with PCR confirmation. And the temptation for people with symptoms to opt for unsupervised, rapid, and lower sensitivity self-testing may lead to false reassurance, as happens with other screening, leading to potential increases in transmission.

• #2 Rapid Tests | Department of Health

  https://www.health-ni.gov.uk/articles/rapid-tests

  Its recommended to use a Rapid Test twice per week. Regular testing helps to identify if you have COVID before it spreads to the people close to you. You should also take a test before attending any social gatherings. […] Yes it is still possible to catch and pass on COVID-19 following vaccination. Some people, including young children and those with health conditions, can’t be vaccinated yet. Regular Rapid Testing helps to keep them safe. […] No if you have COVID-19 symptoms you should book a PCR test.

• #3 How COVID-19 lateral flow tests work | GOV.WALES

  https://www.gov.wales/how-covid-19-lateral-flow-tests-work

  Lateral flow test (LFTs) are used to identify people with COVID-19. […] LFTs are easy to use and give results in 10 to 30 minutes depending on which type of test you have. […] The test kit is a hand-held device with an absorbent pad at one end and a reading window at the other. Inside the device is a strip of test paper that changes colour if COVID-19 proteins are present. […] If you test positive and are eligible for treatments, report it via the NHS 111 Wales COVID-19 Antiviral Self-Referral Form. […] If you are not eligible for COVID-19 treatments and your result is positive please do not report your results on any government, or NHS web pages. You should stay at home and avoid contact with other people until you no longer feel unwell.

• #3 Do At-Home COVID-19 Tests Still Work Well? | TIME

  https://time.com/7018565/do-at-home-covid-tests-still-work/

  These days, many people use at-home COVID-19 tests when they feel ill, rather than going out to get tested by a professional. […] Early in the pandemic, an infected person’s viral load—the amount of virus in their system—tended to peak around the time their symptoms began. […] Now that most everyone has prior immunity from multiple vaccines or infections, the timeline seems to be extended. Viral load now tends to peak around day four or five of symptoms, according to a study published in early 2024. […] A quicker immune response may mean a faster onset of symptoms. […] That immune response can show up as symptoms. […] Pollock and her co-authors estimated that a COVID-19 antigen test is somewhere between 30% and 60% accurate at detecting an infection on someone’s first day of symptoms, but up to 93% accurate on day four.

• #4

  https://www.gov.uk/guidance/understanding-lateral-flow-antigen-testing-for-people-without-symptoms

  Around 1 in 3 individuals with COVID-19 do not display symptoms. […] Lateral flow testing is a fast and simple way to test people who do not have symptoms of COVID-19, but who may still be spreading the virus. […] A test that rapidly detects these otherwise hidden cases is a very useful additional tool for tackling the virus. […] Rapid lateral flow tests give a quick result. They can find positive cases with high levels of virus that are easy to transmit to others, helping to intercept and reduce further infections. […] When levels of virus are high and people are most likely to pass on the disease, lateral flow tests can detect the vast majority of cases. […] Lateral flow is useful for finding out if a person is infectious now, and able to transmit the virus to others. The level of sensitivity is high enough to detect the vast majority of these cases. Lateral flow testing is less likely to return a positive result outside the infectious window.

• #5 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. […] 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. […] If you get a negative result from these self-tests, it means that the test has not been able to detect the COVID-19 virus in your sample. However, you may still be infectious, so you must still follow rules regarding social distancing and face coverings. […] The accuracy of lateral flow tests is also dependent on the person who does the test. […] Clinical evaluation carried out by Public Health England (PHE) and the University of Oxford at the end of 2020 showed that lateral flow tests were accurate enough to be used in the community, including for asymptomatic people, but that the tests performed best when levels of virus are at their highest and people are in the most infectious stage of the disease. […] They found that in people with confirmed COVID-19, antigen tests correctly identified COVID-19 infection in an average of 72% (ranging from 34% to 88%) of people with symptoms, compared with 58% of people without symptoms.

• #6 COVID-19 symptoms and what to do – NHS

  https://www.nhs.uk/conditions/covid-19/covid-19-symptoms-and-what-to-do/

  COVID-19 symptoms can include: a high temperature or shivering (chills) a high temperature means you feel hot to touch on your chest or back (you do not need to measure your temperature) […] a new, continuous cough this means coughing a lot for more than an hour, or 3 or more coughing episodes in 24 hours […] a loss or change to your sense of smell or taste […] shortness of breath […] feeling tired or exhausted […] an aching body […] a headache […] a sore throat […] a blocked or runny nose […] loss of appetite […] diarrhoea […] feeling sick or being sick. […] Most people feel better within a few weeks, but it can take longer to recover. For some people, it can be a more serious illness and their symptoms can last longer. […] If you are eligible for treatments for COVID-19, you should take a rapid lateral flow test as soon as you get symptoms. […] You are no longer required to do a COVID-19 rapid lateral flow test if you have symptoms.

• #7 Coronavirus & COVID-19 Overview: Symptoms, Risks, Prevention, Treatment & More

  https://www.webmd.com/covid/coronavirus

  COVID-19 is a disease caused by SARS-CoV-2 that can trigger what doctors call a respiratory tract infection. The main symptoms include: Fever, Coughing, Shortness of breath, Trouble breathing, Fatigue, Chills, sometimes with shaking, Body aches, Headache, Sore throat, Congestion/runny nose, Loss of smell or taste, Nausea, Diarrhea. The virus can lead to pneumonia, respiratory failure, heart problems, liver problems, septic shock, and death. Many COVID-19 complications may be caused by a condition known as cytokine release syndrome or a cytokine storm. If you notice the following severe symptoms in yourself or a loved one, get medical help right away: Trouble breathing or shortness of breath, Ongoing chest pain or pressure, Confusion, Can’t wake up fully, Bluish lips or face. If you’re infected, symptoms can show up in as few as 2 days or as many as 14. It varies from person to person. According to researchers in China, these were the most common symptoms among people who had COVID-19: Fever 99%, Fatigue 70%, Cough 59%, Lack of appetite 40%, Body aches 35%, Shortness of breath 31%, Mucus/phlegm 27%. Some people who are hospitalized for COVID-19 also have dangerous blood clots, including in their legs, lungs, and arteries. Every case is different. You may have mild flu-like symptoms for a few days after exposure, then get better. But some cases can be severe or fatal. Symptoms can also linger for weeks, even if they’re mild. More than a third of people older than 18 who have signs of the virus aren’t totally recovered 2 or 3 weeks later, according to a CDC survey. Fatigue and cough were the symptoms that were most likely to linger. Some other people who’ve had COVID-19 develop a condition similar to myalgic encephalomyelitis, also known as chronic fatigue syndrome. They may have brain fog, severe fatigue, pain, trouble thinking, or dizziness.

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