[chrisk]

I got the impression that in San Mateo county they were tracking and tracing all along, based on what I received two weeks ago. I have reproduced it below for reference.
 
Thank you for your interest in SM County Health’s actions to investigate contacts as part of our public health protection responsibilities that we are engaged in with the challenge of COVID-19.
 
We are continuing to perform contact investigations for all residents who have tested positive for COVID-19 as well as follow-up on identified exposures in San Mateo County, including ill individuals visiting the area. As the availability of testing increases, we expect to see the number of cases continue to rise. Contact investigation and follow-up is resource-intensive. We are continuing to increase staffing capacity, redirecting Health staff from other areas of responsibility that have been curtailed as we prioritize our essential functions and/or for which demand has lessened, so that new positive results can be investigated quickly even as the number of reports rise.  
 
Regards,
srija
 
Srija Srinivasan
Deputy Chief

San Mateo County Health
(650) 573-2095 T
ssrinivasan@smcgov.org
smchealth.org
facebook.com/smchealth
twitter.com/smchealth



From this, one could conclude they were never overwhelmed. That said, I would like to suggest that one of the main problems in contact tracing and testing has been that we don't know a lot about this virus. AFAIK, we really don't know how common asymptomatic infection is. We really don't know what the incubation period is (defined as the time from exposure until one is contagious to others) We also don't know for sure how long one is typically contagious, although two to three weeks seems to be the number.

Just to be clear, this is how I understand contact tracing and testing works.

1)A patient is diagnosed with COVID-19 (either by PCR test or otherwise). That patient will be quarantined for two to three weeks, but due to the fact we are not yet sure about reinfection the person will need to be quarantined by themselves.

2)The county determines all the people that have been in "significant" contact with this patient (by interviews, by cell phone location, however else).
Determining which "contacts" require follow up is probably a bit of an art. Somehow those contacts will be determined.
Those contacts will be informed that they are presumably exposed. If any of these people have symptoms, they for sure will be either diagnosed with COVID-19 on that basis and/or tested for the virus using a PCR test. For each contact so diagnosed go to step 1 above.

Now comes another tricky part.
3) I believe that ideally you quarantine all the remaining contacts, even though they are not (yet) sick. They also will have to be quarantined by themselves since if they are going to get sick we don't want them spreading the disease to those that are not sick and conversely.
At this point, you also have to decide whether it is worth testing them with a PCR test. They are going to be quarantined anyway. If they test positive the county can immediately go to step 1 with this patient. This is a "win" because it starts contact tracing sooner and should result in less spread. It also allows detection of asymptomatic patients that would not otherwise be detected. If they test negative, you still have to quarantine them because they possibly just haven't developed the disease adequately to test positive. If the testing capacity is adequate, you test. If it isn't, you have to make choices.

As I see it, one big issue is where do you put all those quarantined people. In the US, if you send them home many of them, particularly if they aren't sick, simply won't comply with the quarantine. Ft. Hunter Liggett is nice this time of year. Failing that, how about the Ft. Ord firing ranges. Plenty of sand :-).

So, do I have this right? Comments welcome.

There are plenty of empty hotel rooms. I read about an infected person in SM County who was sent to a hotel to keep him away from his family as well as others.

(Also, the Fairfield Inn in San Carlos was taken over to house sick Grand Princess passengers and is now available for other quarantine purposes).

[chrisk]

I got the impression that in San Mateo county they were tracking and tracing all along, based on what I received two weeks ago. I have reproduced it below for reference.
 
Thank you for your interest in SM County Health’s actions to investigate contacts as part of our public health protection responsibilities that we are engaged in with the challenge of COVID-19.
 
We are continuing to perform contact investigations for all residents who have tested positive for COVID-19 as well as follow-up on identified exposures in San Mateo County, including ill individuals visiting the area. As the availability of testing increases, we expect to see the number of cases continue to rise. Contact investigation and follow-up is resource-intensive. We are continuing to increase staffing capacity, redirecting Health staff from other areas of responsibility that have been curtailed as we prioritize our essential functions and/or for which demand has lessened, so that new positive results can be investigated quickly even as the number of reports rise.  
 
Regards,
srija
 
Srija Srinivasan
Deputy Chief

San Mateo County Health
(650) 573-2095 T
ssrinivasan@smcgov.org
smchealth.org
facebook.com/smchealth
twitter.com/smchealth



From this, one could conclude they were never overwhelmed. That said, I would like to suggest that one of the main problems in contact tracing and testing has been that we don't know a lot about this virus. AFAIK, we really don't know how common asymptomatic infection is. We really don't know what the incubation period is (defined as the time from exposure until one is contagious to others) We also don't know for sure how long one is typically contagious, although two to three weeks seems to be the number.

Just to be clear, this is how I understand contact tracing and testing works.

1)A patient is diagnosed with COVID-19 (either by PCR test or otherwise). That patient will be quarantined for two to three weeks, but due to the fact we are not yet sure about reinfection the person will need to be quarantined by themselves.

2)The county determines all the people that have been in "significant" contact with this patient (by interviews, by cell phone location, however else).
Determining which "contacts" require follow up is probably a bit of an art. Somehow those contacts will be determined.
Those contacts will be informed that they are presumably exposed. If any of these people have symptoms, they for sure will be either diagnosed with COVID-19 on that basis and/or tested for the virus using a PCR test. For each contact so diagnosed go to step 1 above.

Now comes another tricky part.
3) I believe that ideally you quarantine all the remaining contacts, even though they are not (yet) sick. They also will have to be quarantined by themselves since if they are going to get sick we don't want them spreading the disease to those that are not sick and conversely.
At this point, you also have to decide whether it is worth testing them with a PCR test. They are going to be quarantined anyway. If they test positive the county can immediately go to step 1 with this patient. This is a "win" because it starts contact tracing sooner and should result in less spread. It also allows detection of asymptomatic patients that would not otherwise be detected. If they test negative, you still have to quarantine them because they possibly just haven't developed the disease adequately to test positive. If the testing capacity is adequate, you test. If it isn't, you have to make choices.

As I see it, one big issue is where do you put all those quarantined people. In the US, if you send them home many of them, particularly if they aren't sick, simply won't comply with the quarantine. Ft. Hunter Liggett is nice this time of year. Failing that, how about the Ft. Ord firing ranges. Plenty of sand :-).

So, do I have this right? Comments welcome.

There are plenty of empty hotel rooms. I read about an infected person in SM County who was sent to a hotel to keep him away from his family as well as others.

(Also, the Fairfield Inn in San Carlos was taken over to house sick Grand Princess passengers and is now available for other quarantine purposes).