AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |
Back to Blog
Flex flow covid test12/30/2023 ![]() Matthews suggests getting a PCR test, and if that is also positive you could seek additional medical advice, as, although unlikely, in a very small number of cases it may mean you have an underlying medical condition. It’s more likely that “there are some LFTs which seem to be able to detect a very small amount of viral protein for a long time”, she says. ![]() ![]() Petersen agrees that people are “unlikely” to remain infectious, though it is not impossible. “Test results can sometimes remain positive for a period after your isolation ends, but this does not necessarily mean you are still infectious.” Majid says there is no need to keep on testing repeatedly if you have had a positive LFT result confirmed by a PCR test. (A different rule applies if you are an unvaccinated person who has been in close contact with someone who has tested positive: you must self-isolate for 10 days.) The new guidance applies to everyone who has tested positive, regardless of vaccination status. You can cut this isolation period down to seven days if you receive negative LFTs on days six and seven, 24 hours apart. NHS rules state that if you test positive your isolation period begins on the day that your symptoms developed or the day that you took the test if you don’t have symptoms, and ends 10 days later. If you are testing positive on an LFT at the end of the isolation period, are you still infectious and do you still need to isolate? “That should mean more virus and therefore more infectivity in principle, but no one has tested that idea,” he says. However, David Matthews, a professor of virology at the University of Bristol, says that a thicker line could mean – in theory at least – there is more N protein. Azeem Majid, a professor of primary care and public health at Imperial College London, notes that the test is “not designed to estimate how infectious you may be”. Does the thickness of the line on an LFT tell you how infectious you are?ĭouble lines appearing on an LFT – however faint – mean you have detectable virus in your nose and are therefore infectious. Petersen emphasises that “no test offers 100% accuracy, so please consider the risk of getting severe illness among your friends and family”. However, it’s worth bearing in mind that there is a test shortage at the moment, and they are urgently required for key workers, so use them strategically. If you took one early in the morning and are going out in the evening, you might take another, provided there has been a gap of six to 12 hours. ![]() “Omicron replicates very fast, so you may become very infectious within hours,” says Petersen. You could become infectious after you take the test, which is why scientists recommend taking it as close to your social plans as possible, ideally within an hour. How long before meeting family and friends should you take one? However, the gold standard remains the polymerase chain reaction (PCR) test, which detects viral load and infectiousness at lower levels, including before and after the time range in which they are picked up by LFTs. The main benefit of LFTs is they can be carried out quickly and easily at home, with a result in under 30 minutes, and that they don’t need to be sent to a lab. After carrying out tests, the UK Health Security Agency said LFTs have a “comparable sensitivity” for Omicron as for other Covid variants such as Delta. A recent paper demonstrated that LFTs, when used correctly, are likely to have a sensitivity above 80% and in many cases above 90%. The reliability of LFTs depends in part on whether you follow the instructions carefully, which is why studies give varying estimates of their efficacy, from 40% to 90%. “Please continue to test on a daily basis,” urges Irene Petersen, professor of epidemiology and health informatics at University College London. If you have come into contact with an infected person, it could take a few days for a positive result to show up. LFTs identify specific viral proteins that are present inside your nose when coronavirus is infecting you. How do LFTs work and how reliable are they, including for Omicron?
0 Comments
Read More
Leave a Reply. |