Thread by @39Magilla

(1) How does this data show that the #COVID19 incubation period averages 5.2 days with 97.5% of cases presenting within 11.5 days?

In many cases there was a 40 day exposure before symptoms arose.

This is the basis for the 14 day quarantine; is it valid?

github.com/HopkinsIDD/nco…

(2) The blue bars represent the time between the patient's first and last possible exposure to the virus. The blue dots represent the middle of the exposure window.

For two thirds of the cases, the midpoint is over 20 days before symptoms present.

(3) If we look at the time between the start of restrictions & its impact on Confirmed Cases, we see a delay of 17-19 days.

For NY, Social Contact began to drop on 3/5 & reached its lowest value on 4/1.

Confirmed Cases saw an inflection point on 3/22 & started falling on 4/20.

(4) Exposures directly correlate to Social Contact, so the 17-19 days must be Incubation & Symptom Progression.

In NY, Cases & Hospitalizations rose together, b/c the only testing that was performed was Hospital triage.

Symptom progression to Hospitalization averaged 7 days.

(5) Therefore the average Incubation period must be on the order of 12 days, which is much longer than the 5.2 days estimated by the study.

This also would invalidate the basis for the 14 day quarantine.

What assumption was made about those exposure windows?

(6) Credits and References:

Mobility data courtesy of @IHME_UW

New York Daily Statistics courtesy of JHU CCSE

Incubation Research Article courtesy of Annals of Internal Medicine:
annals.org/aim/fullarticl…

(7) PS: If you think I am misinterpreting these exposure windows, please let me know.

I suspect they may be showing us that cumulative exposure may be important.

Also, many cases show very long periods of symptoms, more than 6 weeks. What's with that?