Film, Media & TV1 min ago
Question For The Prof Or Other Sciencey Type
We are told that LFT's should only be used before there are symptoms. I have been trying to find out what the science is behind this (not that i disbelieve it or am against testing) Someone who understands a bit has told me that the reason is that too high a viral load on the test denatures the enzyme used and therefore the test doesn't work. I have hunted and hunted but can't find any research or evidence on this and wondered if anyone with proper knowledge can help?
Thank you.
Yes I know I have put this in the "wrong" category but covid testing IS news and I thought I'd get more traffic here
Thank you.
Yes I know I have put this in the "wrong" category but covid testing IS news and I thought I'd get more traffic here
Answers
Best Answer
No best answer has yet been selected by woofgang. Once a best answer has been selected, it will be shown here.
For more on marking an answer as the "Best Answer", please visit our FAQ.
Hi woofgang
This is all down to the way some of the population are using the LFT tests. To begin with, LFT were never designed to be used by people who had Covid symptoms. Unfortunately,this has never been made very clear. A lot of people have had a negative result from the test when the reality is that they are Covid Positive. These people have merrily gone their way carrying on with their life as normal with obvious potential consequences. In nutshell, LFT's are not for people with symptoms and they are only to be used if you do not have symptoms.
If you have symptoms, you need to self isolated and arrange a PCR test, the gold-standard testing method.
Near my laboratory in the West of England, there is a major issue in some schools as a result of this misunderstanding and it's proving a little difficult to resolve.
This is all down to the way some of the population are using the LFT tests. To begin with, LFT were never designed to be used by people who had Covid symptoms. Unfortunately,this has never been made very clear. A lot of people have had a negative result from the test when the reality is that they are Covid Positive. These people have merrily gone their way carrying on with their life as normal with obvious potential consequences. In nutshell, LFT's are not for people with symptoms and they are only to be used if you do not have symptoms.
If you have symptoms, you need to self isolated and arrange a PCR test, the gold-standard testing method.
Near my laboratory in the West of England, there is a major issue in some schools as a result of this misunderstanding and it's proving a little difficult to resolve.
In some circumstances, there are issues with the nitrocellulose and other components used in some tests that have been corrected along the way with the various manufacturers. High viral load in samples is not an issue in LFT testing but I have seen some remarks in social media about this. Take it all with a pinch of salt.
Great question gingejbee!
I'd use good old table salt, sodium chloride
Lots of salts you shouldn't have nearby when doing the LFT test including any triglyceride salts such as sodium cebacate. Also stay away from carboxylic acids salts and keep your paws out of that jar of cholesterol.
I've just jotted down about 300 off the top of my head but you did ask!!
I'd use good old table salt, sodium chloride
Lots of salts you shouldn't have nearby when doing the LFT test including any triglyceride salts such as sodium cebacate. Also stay away from carboxylic acids salts and keep your paws out of that jar of cholesterol.
I've just jotted down about 300 off the top of my head but you did ask!!
THECORBYLOON, there is absolutely nothing in the make-up of Covid LFT's that mean that symptomatic people should not use them per se.
LFT and PCR tests are used for different purposes.
LFT are only designed to identify people with Covid who are asymptomatic at the time of testing and who can spread the virus inadvertently. In essence, they can determine if a patient is infectious.
PCR tests are there to confirm that a suspected LFT tested who has tested positive with the LFT does indeed have the virus. That patient will be expected to be already self isolating and showing symptoms but the beauty of the test is that it can identify a patient who has already had Covid and recovered from the infection within a certain window via genetic sequencing. It will also identify the variant present. Sometimes, for reasons I won't go into here, a patient is asked to attend a PCR centre without having had a LFT.
The way the body reacts to Covid infection has no bearing on the functioning of either test.
LFT and PCR tests are used for different purposes.
LFT are only designed to identify people with Covid who are asymptomatic at the time of testing and who can spread the virus inadvertently. In essence, they can determine if a patient is infectious.
PCR tests are there to confirm that a suspected LFT tested who has tested positive with the LFT does indeed have the virus. That patient will be expected to be already self isolating and showing symptoms but the beauty of the test is that it can identify a patient who has already had Covid and recovered from the infection within a certain window via genetic sequencing. It will also identify the variant present. Sometimes, for reasons I won't go into here, a patient is asked to attend a PCR centre without having had a LFT.
The way the body reacts to Covid infection has no bearing on the functioning of either test.
Thank you Prof....anecdotally I am hearing from people who are regularly taking LFT's and never getting a positive one but then get pinged and have to get a PCR.....they have carried on doing lft's and never had a positive but the PCR shows positive but still no symptoms. I know there is probabaly not pne cause for this but have you got any thoughts on why this might be?
Thanks woofgang. The easy answer to your question is that LFT tests are not brilliant at detecting asymptomatic covid positive cases. It's a common occurrence and it's possible to have a negative LFT and a positive PCR the following day. You can also have a negative LFT a few days after the positive PCR. False negatives are common. However, they have a place in detection as they do pick up cases in any asymptomatic group that would otherwise not be tested at all. Consider them a tool on the detection pathway.
This is why large companies with hundreds or thousands of employees on site use LFT tests. The same thinking applies to large schools, colleges etc.
This is why large companies with hundreds or thousands of employees on site use LFT tests. The same thinking applies to large schools, colleges etc.
additional question if I may; It appears that the omicron virus variation is highly infectious but the stats seem to show that it doesn't have severe effects - few hospitalisations & no deaths.
As we are all going to get covid in some form or another, would it not be better to catch the omicron variation and reach the herd immunity which eventually is the only way all epidemics end?
As we are all going to get covid in some form or another, would it not be better to catch the omicron variation and reach the herd immunity which eventually is the only way all epidemics end?
Khandro, omicron is highly transmissible. Hospitalisation of a patient with Omicron in the UK has occurred this weekend but you are correct that no deaths have occurred here to date.
Epidemics don't always end because of herd immunity, but herd immunity is unlikely to be achieved with covid for a number of reasons.
Firstly, the virus continues to mutate and there have been subtle but minor changes to the spike protein in sequencing results since omicron came on the scene. These changes may be of no great significance but there have been hundreds of mutation since the Wuhan virus was discovered, some of which have proved dangerous, others not so.
Secondly, the difficulty is that herd immunity is unlikely to be achievable due to the massive number of people who do not wish to have the vaccine, the group that cannot be vaccinated for medical reasons and people like those with no fixed address that are missing from official records. People coming and going into the UK unrecorded is also problematical. Whilst the unvaccinated are out there in the community, they remain vectors of the disease and again herd immunity will never be possible. Remember that a new mutation is more easily achievable for the virus in the unvaccinated.
Vaccines are there to reduce the risk of hospitalisation, reduce the risk of serious illness and death and reduce the risk of a patient catching or transmitting the virus. Right now, if enough people catch the omicron variant and end up in hospital, that will be a catastrophe for the NHS and I'm with the great and the good on that.
Epidemics don't always end because of herd immunity, but herd immunity is unlikely to be achieved with covid for a number of reasons.
Firstly, the virus continues to mutate and there have been subtle but minor changes to the spike protein in sequencing results since omicron came on the scene. These changes may be of no great significance but there have been hundreds of mutation since the Wuhan virus was discovered, some of which have proved dangerous, others not so.
Secondly, the difficulty is that herd immunity is unlikely to be achievable due to the massive number of people who do not wish to have the vaccine, the group that cannot be vaccinated for medical reasons and people like those with no fixed address that are missing from official records. People coming and going into the UK unrecorded is also problematical. Whilst the unvaccinated are out there in the community, they remain vectors of the disease and again herd immunity will never be possible. Remember that a new mutation is more easily achievable for the virus in the unvaccinated.
Vaccines are there to reduce the risk of hospitalisation, reduce the risk of serious illness and death and reduce the risk of a patient catching or transmitting the virus. Right now, if enough people catch the omicron variant and end up in hospital, that will be a catastrophe for the NHS and I'm with the great and the good on that.
Prof. Thank you, - //.... the difficulty is that herd immunity is unlikely to be achievable due to the massive number of people who do not wish to have the vaccine, the group that cannot be vaccinated for medical reasons and people like those with no fixed address that are missing from official records. People coming and going into the UK unrecorded is also problematical.//
But then this cohort will most likely contract covid & either survive it (there after have immunity) or not, why is everything biased towards in the UK to saving the NHS?
I speak as one who has had two jabs (moderna) then after 1 week I fainted & collapsed - for the first time in my long life & then 3 weeks later had a stroke ("mini") I was hospitalised for three days, when I point out the obvious connection to a variety of medics I get a blank stare. I have paid to have a blood test for antibodies instead, which is fortunately high. The stats we are being fed every day are of infections and deaths but I have yet to see any on people who have suffered serious 'side effects' which I anecdotally find must be very high.
I now refuse to have anymore vaccinations, in fact I'd rather risk death than suffer a severe stroke leaving me incapacitated.
But then this cohort will most likely contract covid & either survive it (there after have immunity) or not, why is everything biased towards in the UK to saving the NHS?
I speak as one who has had two jabs (moderna) then after 1 week I fainted & collapsed - for the first time in my long life & then 3 weeks later had a stroke ("mini") I was hospitalised for three days, when I point out the obvious connection to a variety of medics I get a blank stare. I have paid to have a blood test for antibodies instead, which is fortunately high. The stats we are being fed every day are of infections and deaths but I have yet to see any on people who have suffered serious 'side effects' which I anecdotally find must be very high.
I now refuse to have anymore vaccinations, in fact I'd rather risk death than suffer a severe stroke leaving me incapacitated.
very clear concise answers
The hacks dont really understand all this. The hacks have ignored the content. Tonight they are warbling about the full frontal face presentation - this is a tee-vee sign of "its all true" and they do it for Laura Lee - Kuensberg - because she truths the whole time
( you are getting the drift)
and they are VERY resistant to allowing politicians to do it
[Charles de gaulle did it the whole time - Francais et Francaises! - different culture]
usually they demand that the politico is at an angle - no agreement then no interview and no air time
The hacks dont really understand all this. The hacks have ignored the content. Tonight they are warbling about the full frontal face presentation - this is a tee-vee sign of "its all true" and they do it for Laura Lee - Kuensberg - because she truths the whole time
( you are getting the drift)
and they are VERY resistant to allowing politicians to do it
[Charles de gaulle did it the whole time - Francais et Francaises! - different culture]
usually they demand that the politico is at an angle - no agreement then no interview and no air time
Latest Posts
Film, Media & TV1 min ago
Gb News, Advent, Christian Message
News4 mins ago
Trump - An Apparent Warning To Hamas
News6 mins ago
Related Questions
Sorry, we can't find any related questions. Try using the search bar at the top of the page to search for some keywords, or choose a topic and submit your own question.