As I responded to the sibling comment, I don't think that is accurate. Of course many, if not most cases can not be traced, many certainly can be. Some people know exactly where they got covid, and who they exposed, and where.
The US has 50,000 full time contact tracers working to collect this information. Surely there is some data by now?
>Your questions are unanswerable.
IF the question is categorically unanswerable (which I don't believe), contact tracing programs should be disbanded.
Instead, please think of it as "one of the most powerful, non-medicinal, mechanisms for interrupting disease transmission."
It accomplishes this through its overt actions: attempting to alter the behavior of potential and exposed contacts by encouraging quarantining for an appropriate length of time and to get tested if symptoms develop.
I disagree. Understanding how and where COVID spreads has been an essential part of contract tracing in all of the countries that have successfully implemented it. This data is absolutely collected by tracers.
http://publichealth.lacounty.gov/media/coronavirus/data/cont...
http://publichealth.lacounty.gov/media/coronavirus/locations...
Full disclosure: I've had covid.
We assume we were exposed at the clinic, where our kid needed emergency medical treatment. But if so, only one of us was with the child indoors -- in a cleaned room with a doctor in full PPE and us in masks -- and treatment lasted less than 5 minutes.
But by the time we experienced onset of symptoms, days later, we had been in close proximity with my in-laws (they need care and were part of our bubble) for over 24 hours. Luckily, they developed no symptoms and tested negative.
So 5 minutes of exposure to an asymptomatic carrier at the clinic likely transmitted the virus to us, but 24 hours in close contact failed to transmit the virus to my in-laws.
The delay of onset and inconsistent transmission patterns make this virus exceedingly difficult and expensive to track. Your questions are unanswerable.