In 20200507h Day 128: About 8 day average confirmed COVID-19 case doubling time since first case Nov 17, 2019, I noted that assuming a first case of COVID-19 on November 17, 2019, if confirmed cases had doubled every 8 days, then today we would have 4,194,304 cases. Well, an hour ago I took a screenshot of the two coronavirus trackers and the average of the two is 4,196,452. Due to the social distancing measures now in place throughout the world, to the seasonal nature of coronavirus infections, and to the now ramped up testing, we are no longer increasing cases at an 8-day doubling rate.
If our confirmed cases had exactly doubled every 8 days, here is how the cases would have grown, with comparison to confirmed cases reported:
|Date||Cases 8-day Double||Cases Confirmed|
|2019-12-19h||16||11 (paper), 27-60 (SCMP)|
|2019-12-27F||32||34 (paper), 180+ (SCMP)|
|2020-01-04S||64||92 (paper), 381+ (SCMP)|
|2020-01-28T||512||6058 (widespread testing)|
*NOTE: 4,196,452 is the average confirmed cases from https://coronavirus.jhu.edu and https://www.worldometers.info/coronavirus/ at the time of writing this. Other confirmed case values starting January 28th are from worldometers.info. Before January 28th, confirmed cases were taken from Early Transmission Dynamics in Wuhan, China, of Novel Coronavirus–Infected Pneumonia and from First WHO Situation Report.
A reference for the first coronavirus case on Nov. 17, 2019 is from SCMP.com: Coronavirus: China’s first confirmed Covid-19 case traced back to November 17. In this article it is reported:
According to the government data seen by the Post, a 55 year-old from Hubei province could have been the first person to have contracted Covid-19 on November 17.
From that date onwards, one to five new cases were reported each day. By December 15, the total number of infections stood at 27 – the first double-digit daily rise was reported on December 17 – and by December 20, the total number of confirmed cases had reached 60.
On December 27, Zhang Jixian, a doctor from Hubei Provincial Hospital of Integrated Chinese and Western Medicine, told China’s health authorities that the disease was caused by a new coronavirus. By that date, more than 180 people had been infected, though doctors might not have been aware of all of them at the time.
By the final day of 2019, the number of confirmed cases had risen to 266, On the first day of 2020 it stood at 381.