[M T]

Contract tracing has been happening in  NY, FL, TX, CA, and all the other state.  If any one of them said, we're seeing a lot of cases that we can associate with  X (for any X) then we'd expect X to be in the CA list of things to rein in, or the ones in Texas, or elsewhere.

I don't know why we haven't seen any studies on transmission spots (that I'm aware of).  The little we see, like demographics, are coming out of the government institutions.   Even something as little as saying that N% of the cases are spread in the household would help.  Even SCC's info about construction workers was muddied because no one reported that spread was happening at construction sites, only that there were a number of cases being found where they were checking symptoms before work at construction sites.

I was looking at San Antonio numbers.  Of the 21K cases, they have identified sources for 7800 of them.  Of those, 57% are close contact, 37% are community spread, 6% travel.   I wonder if that is distorted by the easy cases of "I know I got it from a household member".   If so, that suggests that maybe only about 20% (4440/21000) are from easy-to-identify contacts.

If one quits wondering why they aren't doing contact tracing and starts wondering why contact tracing isn't identifying the sources (even if only for the infectees), one begins to think that community spread is easier and perhaps more unreliable than we've been thinking.   But it is really hard to follow the embers in a wild fire.

[M T]

Contract tracing has been happening in  NY, FL, TX, CA, and all the other state.  If any one of them said, we're seeing a lot of cases that we can associate with  X (for any X) then we'd expect X to be in the CA list of things to rein in, or the ones in Texas, or elsewhere.

I don't know why we haven't seen any studies on transmission spots (that I'm aware of).  The little we see, like demographics, are coming out of the government institutions.   Even something as little as saying that N% of the cases are spread in the household would help.  Even SCC's info about construction workers was muddied because no one reported that spread was happening at construction sites, only that there were a number of cases being found where they were checking symptoms before work at construction sites.

I was looking at San Antonio numbers.  Of the 21K cases, they have identified sources for 7800 of them.  Of those, 57% are close contact, 37% are community spread, 6% travel.   I wonder if that is distorted by the easy cases of "I know I got it from a household member".   If so, that suggests that maybe only about 20% (4440/21000) are from easy-to-identify contacts.

If one quits wondering why they aren't doing contact tracing and starts wondering why contact tracing isn't identifying the sources (even if only for the infectees), one begins to think that community spread is easier and perhaps more unreliable than we've been thinking.   But it is really hard to follow the embers in a wild fire.