[M T]

• The attitude that you have to have symptoms in order to get tested scares me as those with the disease have been spreading it before they have symptoms (see my post early this morning for the medical article indicating the early massive virus shedding).  This attitude will lead to explosive growth.
  

Does anybody here know at what point in the process of getting sick the current test(s) can detect the disease fairly reliably? If T designates the first day with detectable symptoms, does the test indicate positive on day T - 1, T - 2, T -4, ...? If anybody knows, please enlighten us and share your info. It may be out there, but I haven't seen it.

The Feb 24 US-China Joint Mission final report indicated

According to preliminary data from Guangzhou CDC as of 20 February, virus can initially be detected in upper respiratory samples 1-2 days prior to symptom onset

However, I believe that is updated by newer data.

If you are asking about presymptomatic infection, then you may want to ask:
  1) How long after exposure does a swabbing give positive results?
  2) How long after exposure are you shedding virus sufficient to infect someone?
  3) How long after exposure do symptoms appear?
  4) How long after swabbing are the test results available?
I think aKidDoc answered parts of those, not necessarily with hard data.  If I understand correctly, for this disease, the answer to question 2 is pretty close to the answer to question 1.

Similar investigation in The serial interval of COVID-19 from publicly reported confirmed cases

The serial interval of COVID-19 is defined as the time duration between a primary case (infector) developing symptoms andsecondary case (infectee) developing symptoms. ...
We estimate a mean serial interval for COVID-19 of 3.96 [95% CI3.53-4.39] with a standard deviation of 4.75 [95% CI 4.46-5.07].  Notably, 59 of the 468 reports indicate that the infectee developed symptoms earlier than the infector.

Their minimum serial interval was -11, which would mean that the virus in patient A caused another infection more than 11 (around 15) days before symptoms appeared in patient A. Asymptomatic patients (there are some) would have an undefined value as they never show the symptoms.

The previously mentioned Transmission interval estimates suggest pre-symptomatic spread of COVID-19

The mean incubation period was 7.1 (6.13, 8.25) days for Singapore and 9 (7.92, 10.2)days for Tianjin. The mean serial interval was 4.56 (2.69, 6.42) days for Singapore and 4.22 (3.43, 5.01) for Tianjin.

For China, test results were available the same day (I believe I saw 3 hours).  Until recently, US tests had to go to CDC for testing, which involved shipping delays, resulting in possibly 48 hours for results.  I'm sure it is better now.  A number of metropolitan areas have test facilities.

The WHO-China report (dated Feb 24) also had this:

Overall, producers have the capacity to produce and distribute as many as 1,650,000 tests/week.

---

Yeah, because this was rolled out so quickly, implementing additional questoinnaires has caused up to 6-hour lines to get through customs, which of course means the very people most likely to be contagious are all trapped in one gigantic room together for hours on end...:

Whew, it is a good thing that Santa Clara County included this in the order limiting gatherings:

A "gathering" does not include normal operations at airports or spaces where persons may be in transit.

If those lines were at the San Jose airport, SCC wouldn't need to have the sheriff come in and cite the airport or the immigration authorities.

[M T]

• The attitude that you have to have symptoms in order to get tested scares me as those with the disease have been spreading it before they have symptoms (see my post early this morning for the medical article indicating the early massive virus shedding).  This attitude will lead to explosive growth.
  

Does anybody here know at what point in the process of getting sick the current test(s) can detect the disease fairly reliably? If T designates the first day with detectable symptoms, does the test indicate positive on day T - 1, T - 2, T -4, ...? If anybody knows, please enlighten us and share your info. It may be out there, but I haven't seen it.

The Feb 24 US-China Joint Mission final report indicated

According to preliminary data from Guangzhou CDC as of 20 February, virus can initially be detected in upper respiratory samples 1-2 days prior to symptom onset

However, I believe that is updated by newer data.

If you are asking about presymptomatic infection, then you may want to ask:
  1) How long after exposure does a swabbing give positive results?
  2) How long after exposure are you shedding virus sufficient to infect someone?
  3) How long after exposure do symptoms appear?
  4) How long after swabbing are the test results available?
I think aKidDoc answered parts of those, not necessarily with hard data.  If I understand correctly, for this disease, the answer to question 2 is pretty close to the answer to question 1.

Similar investigation in The serial interval of COVID-19 from publicly reported confirmed cases

The serial interval of COVID-19 is defined as the time duration between a primary case (infector) developing symptoms andsecondary case (infectee) developing symptoms. ...
We estimate a mean serial interval for COVID-19 of 3.96 [95% CI3.53-4.39] with a standard deviation of 4.75 [95% CI 4.46-5.07].  Notably, 59 of the 468 reports indicate that the infectee developed symptoms earlier than the infector.

Their minimum serial interval was -11, which would mean that the virus in patient A caused another infection more than 11 (around 15) days before symptoms appeared in patient A. Asymptomatic patients (there are some) would have an undefined value as they never show the symptoms.

The previously mentioned Transmission interval estimates suggest pre-symptomatic spread of COVID-19

The mean incubation period was 7.1 (6.13, 8.25) days for Singapore and 9 (7.92, 10.2)days for Tianjin. The mean serial interval was 4.56 (2.69, 6.42) days for Singapore and 4.22 (3.43, 5.01) for Tianjin.

For China, test results were available the same day (I believe I saw 3 hours).  Until recently, US tests had to go to CDC for testing, which involved shipping delays, resulting in possibly 48 hours for results.  I'm sure it is better now.  A number of metropolitan areas have test facilities.

The WHO-China report (dated Feb 24) also had this:

Overall, producers have the capacity to produce and distribute as many as 1,650,000 tests/week.

---

Yeah, because this was rolled out so quickly, implementing additional questoinnaires has caused up to 6-hour lines to get through customs, which of course means the very people most likely to be contagious are all trapped in one gigantic room together for hours on end...:

Whew, it is a good thing that Santa Clara County included this in the order limiting gatherings:

A "gathering" does not include normal operations at airports or spaces where persons may be in transit.

If those lines were at the San Jose airport, SCC wouldn't need to have the sheriff come in and cite the airport or the immigration authorities.