So the chain of events is you are a positive case. You leave your number with the testing crowd. The testing crowd inform you if you are positive? The trace crowd then have to call you to get your movements for 48 hours prior to when you were confirmed. Then try get all possible contacts from within that timeframe, get their phone numbers and contact them to inform them to get tested at which point if they test positive it repeats.
Now Iād imagine that is manageable and effective at low numbers of transmission
At high numbers of transmission I would say it is a nightmare and largely ineffective as your chances of getting everyone are impossible. Hence measures
This is a very instructive article on the challenges in the U.S - some of the quoted numbers would be similar to here, not with regards actual tracing, but wrt to the people who would answer their phones, or be compliant with tracers etc
I think most people in this country identified as close contacts would be reasonably cooperative, maybe that is not the case. Forget the reluctant / difficult close contacts, hang up and move on.
If the tracers managed to get even 50% of contacts to isolate pending a test surely it would quickly lead to a significant reduction in numbers.
Itās logical to think that but unless testing and tracing is turned around pretty much instantaneously it is not effective at reducing numbers. I think we are at a 3.8 day turnaround, which has fuck all effect on reducing the rate of transmission based on studies.
for every 50% of the people you miss they are possible out and about spreading at the effective R0
It is absolutely effective and necessary at low levels of community transmission to track/trace and isolate in order to contain it. If the same problems exist and you only get 50% of cases you eventually get to high levels of community transmission again
South Korea were able to do with as they have a specific law for infectious diseases which mandates people to give certain information to the tracers, also, they have effective digital tracing on cards, phones, cameras etc.
We are woefully under prepared to implement a tracing only strategy
Not as much as we had last month but community transmission is still high.
so in the past fortnight from last night - 5,778 cases were notified. roughly 60% associated to known outbreaks or travel/healthcare. 40% they havenāt a clue where it came from.
According to Esteban thereās no point in contact tracing. If you donāt trace and test close contacts how can you effectively assess the R number?
This sounds like catch 22.
-Weāll open up when we get the R number down said major major.
-How will we know when the R number comes down asked yossarian.
-We donāt measure the R number so we wonāt know when it comes down.
-Then how will we know when to open up?
-We canāt know when to open up because we are locked down.
if you donāt trace and test EVERY close contact how can you effectively assess the R number?
You can guess
Tracing and isolating is ineffective at high levels of transmission. It will not reduce the level of transmission. Measures and adherence to those measures will. As numbers reduce from measures, testing and tracing becomes more effective and necessary to keep them low, especially as measures and restrictions are eased and lifted.
Youāre saying weād prefer to guess rather than make an effort to gather data? Iāll repeat again, we are not currently in a state of high transmission.
