This was a great article. Very informative and a great breakdown of the different testing methods.
I hear a lot about the idea that the higher the cycle threshold the result comes back positive on RT-PCR, the harder it is to know what stage of infection someone is at with sars-cov-2, especially if they are not showing symptoms of Covid-19. I do not have the expertise to know, but is there a difference between a positive PCR case at different cycle thresholds?
This question would only make sense depending on the above but…If PCR by itself has room to not paint the entire picture, do you think if you got a positive PCR result above a particular CT value + are immunised + have the blood prick test(Or other?) to show you have a strong, potentially previously developed immune response, that should mean something in regards to quarantine/managed isolation/risk of spreading infection?
My concern is, do we run the risk of the public becoming unsettled/loss of trust in govt if we do not manage more dynamically (sometime over the next 12 months) case identification, lockdowns and individuals needing to isolate? If we take a more blanket approach for another two years, it is hard to see the public continually being so supportive to "follow the rules", and it may result in a growing lack of trust, which may weaken public response to future events when high public trust will be crucial. However, you may have already mentioned the solution to this in your article if the solution lies in "new & better" testing technologies.
Sorry for the two-part question. The 1st part, I am sure, will be easier to answer. The 2nd part ties into more social/cultural trends developing. Although not as much of an acute problem right now, these social trends may be a lasting "rash" we may have to deal with long after covid is behind us. There is probably no black/white answer to this, but macro population trends do not always follow the science no matter how well communicated it is, as most people/populations are not scientists. Anxiety, fear, and frustration are powerful emotions when experienced at a population level, especially how they can affect an individual's rational decision-making and how they act as "collective" individuals in society. I worry that if these types of emotional factors are not addressed, then that anxiety, fear and frustration can turn to anger. I don't think anyone on either side of these issues wants to see significantly large populations of people displaying emotions of anger. How do we avoid that in a world of differing opinions? Who knows! But could using the same strategies that put us there in the first place, rightly or wrongly, may only exacerbate the problem?
This may be just one of the many risk/benefit scenarios that we simply have to deal with, which is impossible to have a perfect outcome or accurately predict what effect it will have. I am sure we have some good economists at the decision-making table giving input with the scientist on this!
Great feedback/observations and poignant questions James. In terms of knowing what stage of the infection the person is at or even the viral load, RT-PCR results are not applicable. All that the CT value tells us is how much viral RNA there was in that particular sample. The higher the value, the lower the amount of viral RNA present in the sample that was taken. It's all chance and probability really. Which is why being more cautious around the definitive status of testing is important as well as having qualified professionals perform the sample gathering. Anyone can stick a cotton bud up their nose but it takes a skilled technician to make sure that all of the surface area is covered in the swab. Hence why I am a bit wary of home testing kits.
I think the most promising future diagnostics we have in the pipeline at the moment are the breathalyser combined with the isothermal amplification and then followed by serology. Like you say, this would give us a much greater understanding of background infection duration as well as potential viral load status.
As for the general public losing their ability to be patient and act within proper pandemic protocols, only time will tell. I think Denmark is a good gauge of how things will turn out for us. Getting 90%+ vaccinated was a pretty stellar achievement and to get people to understand the significance of immunisation versus testing to help curb the spread is still important. I am a bit disappointed that we have seemingly given up in our ability to stamp out the virus and that now all the focus seems to be on mitigating hospitalisation and severe disease. We managed to get rid of both SARS (1) and MERS which, granted, didn't affect as wide a global population but still are very similar respiratory infections.
I think New Zealand is poised to be at the cutting edge of how we move forward out of this pandemic and what, if any, diagnostic precautionary testing we develop as a standard. I think the hygiene protocols, mask wearing, hand washing and social distancing are here to stay as for all the other procedures, let's just wait and see.
Chris,
This was a great article. Very informative and a great breakdown of the different testing methods.
I hear a lot about the idea that the higher the cycle threshold the result comes back positive on RT-PCR, the harder it is to know what stage of infection someone is at with sars-cov-2, especially if they are not showing symptoms of Covid-19. I do not have the expertise to know, but is there a difference between a positive PCR case at different cycle thresholds?
This question would only make sense depending on the above but…If PCR by itself has room to not paint the entire picture, do you think if you got a positive PCR result above a particular CT value + are immunised + have the blood prick test(Or other?) to show you have a strong, potentially previously developed immune response, that should mean something in regards to quarantine/managed isolation/risk of spreading infection?
My concern is, do we run the risk of the public becoming unsettled/loss of trust in govt if we do not manage more dynamically (sometime over the next 12 months) case identification, lockdowns and individuals needing to isolate? If we take a more blanket approach for another two years, it is hard to see the public continually being so supportive to "follow the rules", and it may result in a growing lack of trust, which may weaken public response to future events when high public trust will be crucial. However, you may have already mentioned the solution to this in your article if the solution lies in "new & better" testing technologies.
Sorry for the two-part question. The 1st part, I am sure, will be easier to answer. The 2nd part ties into more social/cultural trends developing. Although not as much of an acute problem right now, these social trends may be a lasting "rash" we may have to deal with long after covid is behind us. There is probably no black/white answer to this, but macro population trends do not always follow the science no matter how well communicated it is, as most people/populations are not scientists. Anxiety, fear, and frustration are powerful emotions when experienced at a population level, especially how they can affect an individual's rational decision-making and how they act as "collective" individuals in society. I worry that if these types of emotional factors are not addressed, then that anxiety, fear and frustration can turn to anger. I don't think anyone on either side of these issues wants to see significantly large populations of people displaying emotions of anger. How do we avoid that in a world of differing opinions? Who knows! But could using the same strategies that put us there in the first place, rightly or wrongly, may only exacerbate the problem?
This may be just one of the many risk/benefit scenarios that we simply have to deal with, which is impossible to have a perfect outcome or accurately predict what effect it will have. I am sure we have some good economists at the decision-making table giving input with the scientist on this!
Great feedback/observations and poignant questions James. In terms of knowing what stage of the infection the person is at or even the viral load, RT-PCR results are not applicable. All that the CT value tells us is how much viral RNA there was in that particular sample. The higher the value, the lower the amount of viral RNA present in the sample that was taken. It's all chance and probability really. Which is why being more cautious around the definitive status of testing is important as well as having qualified professionals perform the sample gathering. Anyone can stick a cotton bud up their nose but it takes a skilled technician to make sure that all of the surface area is covered in the swab. Hence why I am a bit wary of home testing kits.
I think the most promising future diagnostics we have in the pipeline at the moment are the breathalyser combined with the isothermal amplification and then followed by serology. Like you say, this would give us a much greater understanding of background infection duration as well as potential viral load status.
As for the general public losing their ability to be patient and act within proper pandemic protocols, only time will tell. I think Denmark is a good gauge of how things will turn out for us. Getting 90%+ vaccinated was a pretty stellar achievement and to get people to understand the significance of immunisation versus testing to help curb the spread is still important. I am a bit disappointed that we have seemingly given up in our ability to stamp out the virus and that now all the focus seems to be on mitigating hospitalisation and severe disease. We managed to get rid of both SARS (1) and MERS which, granted, didn't affect as wide a global population but still are very similar respiratory infections.
I think New Zealand is poised to be at the cutting edge of how we move forward out of this pandemic and what, if any, diagnostic precautionary testing we develop as a standard. I think the hygiene protocols, mask wearing, hand washing and social distancing are here to stay as for all the other procedures, let's just wait and see.