[Goose]

[*] Do they consider contact tracing, by its effects so far, to be effective & efficient at reducing spread?
[*] Why are so many cases are being considered community spread, apparently signifying that they weren't being alerted by contact tracing?
  Lack of cooperation?  COVID-19 is primarily NOT spread by close contacts?   Widespread undetected cases?  Is this info being collected from new cases before they are being contacted as a result of contact tracing of their infectors (ie, contact tracing is too slow to be effective)?
[*] The "contact to a case" numbers are so low that it implies there is almost no spread in households.  Is that true, or is something else going on?  
[/list]

All good questions. Would be nice if the news media were asking them, but if they are, it isn't being made public.

An additional question regarding "Contacts to a Case" is whether SCC actually successfully contacted the person, or does it just mean they had the person's name as a contact? If it is the latter, some of these people aren't being informed they have been exposed and don't quarantine. That would make the effect of contact tracing even lower than the 19% by how many people they didn't reach.

As of right now, R in Santa Clara County is 1.11. Getting that number below 1 is the minimum goal. Contact tracing doesn't have to be great in order to help a lot. Notionally, if we could get the "Contacts to a Case" (that are actually contacted and quarantined) up to 28%, R would drop to 1. Probably not quite that simple but as a first approximation that would stop the increase in cases.

MT has fortunately tracked this data over time, because for some reason SCC provides only a cumulative summary. This is annoying because previous weeks performance affects the numbers displayed on the site. This is just kind of silly IMHO. I can see that the number needs to be a 7 day moving average or some equivalent thing to reduce noise in the data. but cumulative is not all that useful.

SCC also does not tell us how many of the cases (people who tested positive) they actually reached. If they are only contacting a small percentage of the positive cases, they can't obtain adequate numbers of contacts, even with good cooperation. We need to know how many cases they actually contacted.

We also need to know how many contacts they were actually given. If they are getting 100 cases per day and averaging 20 contact names per day, there is no way they can get above 20% cases related to a contact, no matter what they do. We then need to know how many of these contacts they actually reached, because only those people matter. Contacts you can't reach don't count. If we knew these numbers, we would actually know how things were going. SCC needs to know those numbers in order to figure out what they need to fix. If they have them, why don't they make them public?

[Goose]

[*] Do they consider contact tracing, by its effects so far, to be effective & efficient at reducing spread?
[*] Why are so many cases are being considered community spread, apparently signifying that they weren't being alerted by contact tracing?
  Lack of cooperation?  COVID-19 is primarily NOT spread by close contacts?   Widespread undetected cases?  Is this info being collected from new cases before they are being contacted as a result of contact tracing of their infectors (ie, contact tracing is too slow to be effective)?
[*] The "contact to a case" numbers are so low that it implies there is almost no spread in households.  Is that true, or is something else going on?  
[/list]

All good questions. Would be nice if the news media were asking them, but if they are, it isn't being made public.

An additional question regarding "Contacts to a Case" is whether SCC actually successfully contacted the person, or does it just mean they had the person's name as a contact? If it is the latter, some of these people aren't being informed they have been exposed and don't quarantine. That would make the effect of contact tracing even lower than the 19% by how many people they didn't reach.

As of right now, R in Santa Clara County is 1.11. Getting that number below 1 is the minimum goal. Contact tracing doesn't have to be great in order to help a lot. Notionally, if we could get the "Contacts to a Case" (that are actually contacted and quarantined) up to 28%, R would drop to 1. Probably not quite that simple but as a first approximation that would stop the increase in cases.

MT has fortunately tracked this data over time, because for some reason SCC provides only a cumulative summary. This is annoying because previous weeks performance affects the numbers displayed on the site. This is just kind of silly IMHO. I can see that the number needs to be a 7 day moving average or some equivalent thing to reduce noise in the data. but cumulative is not all that useful.

SCC also does not tell us how many of the cases (people who tested positive) they actually reached. If they are only contacting a small percentage of the positive cases, they can't obtain adequate numbers of contacts, even with good cooperation. We need to know how many cases they actually contacted.

We also need to know how many contacts they were actually given. If they are getting 100 cases per day and averaging 20 contact names per day, there is no way they can get above 20% cases related to a contact, no matter what they do. We then need to know how many of these contacts they actually reached, because only those people matter. Contacts you can't reach don't count. If we knew these numbers, we would actually know how things were going. SCC needs to know those numbers in order to figure out what they need to fix. If they have them, why don't they make them public?