Would a Moonshot work?

[Splodgetastic]

I am not a scientist, hence my question, but if you tested negative could you still be incubating a virus / able to transmit it?

No idea what the moon bit is, but the tests aren't 100% certain ... you can worry too much. I only had a test as part of a study, text screenshot attached.

My DS has a cold now with occasional cough, so I'm sure school will want him to test. See what they say Monday.

Yes you could. You could be a false negative for a start. But for moonshot to work you don’t need everyone to get the correct test result, you just need enough that R

That is helpful. I have realised that I was asking the wrong question or had two questions. Assuming the test is 100% accurate, could you be incubating the virus (such that it wouldn’t show up on the test at that stage)? So, we’ve answered the question about false negatives, but are there also correct negatives but you are still incubating? (Presumably Moonshot could still work if we most cases were picked up.). I think Moonshot is meant to be a daily rapid test (presumably along with the random Class A drugs testing Priti Patel wants employers to implement).

The incubation question I would be interested to know the answer to as well. As people are infectious for 48 hours prior to symptoms, the whole thing would be pointless if the test didn’t detect those who are in that 48 hour window. But I don’t know enough about the testing to know if the tests would detect those.

If you were incubating but not within the 48 hour pre symptom infectious period, it doesn’t really matter. As I understand it the moonshot idea is just to allow people to do certain things like go to a concert, go to a football match etc so the result only matters to allow them to do something at that time. Italy are apparently using something similar at I think it’s Milan airport and screen everyone pre flight. So if you were incubating but it picked up those in the infectious but pre symptom period, then I can see how it works. If it fails to pick up those, it’s a waste of time.

The theory is that if you are in the very early stages of incubation, you are not yet shedding the virus in sufficient quantities to deliver an infective dose. You only become infectious a couple of days before symptoms.

So the Holy Grail here is a test that can deliver a sufficiently reliable positive result early on - ideally at the point where you are still building up the amount in your body, enough for detection but before or at the point you become infectious.

This is very interesting. I don't have much of an understanding of science, which I think makes it difficult for me to understand what is going on and concepts of risk, but I do remember my DM having a leaflet of childhood diseases that talked about the "incubation period" and the "isolation period" so I was just interested how that worked with Covid and the Moonshot, when the incubation period is thought to be 7 to 10 days and isolation 14 days.

Assuming the test is 100% accurate, could you be incubating the virus (such that it wouldn’t show up on the test at that stage)?

Yes yes yes (I am qualified to answer).

The general opinion is that you are very unlikely to test negative AND be infectious to others, though. Neither in that moment and in the very near future, so might be safely not infectious for next 36 hours or so. This opinion is based on both observations of real-life transmission chains and theory (understanding how transmission happens).

Honestly I can't keep up with latest, but months ago there was a good study showing the viral load in throat became detectable about 36 hours before symptoms started, and peaked about 12 hours before symptoms started. Majority view is that without coughing or spluttering, this silent-high-viral load person still seems highly unlikely to pass it on.

Some people are talking about airborne & aerosols: these are on a probability distribution with droplet transmission at one end and airborne at the other. The vast majority of covid transmissions must be via droplets; if droplet transmission is well controlled, transmission from the other types will decline sharply too. It makes sense to worry first about controlling the main transmission pathway.

Low risk is not = Absolute zero risk. There's no proper discussion going on about acceptable levels of risk.