Georgia Gov. Brian Kemp says he didn’t know asymptomatic people could transmit coronavirus from Newsweek, 2 Apr 2020
Individuals could have been infecting people before they ever felt bad, but we didn’t know that until the last 24 hours.
As shocking as his lack of knowledge on a pandemic that is changing the world society is, it’s important to note: “symptomatic” is to a degree subjective. Some people have higher base temperatures, are they symptomatic? Some cough regularly. Some have IBS. Unless there is an obvious degradation of health, there is really no well-defined checklist of factors to make someone symptomatic. So when is it safe to allow widespread personal integration and travel? I’m going to be an asshole and quote myself:
Viruses that show symptoms faster and that kill their hosts faster will have a more limited spread. COVID-19’s delay and lower fatality rate may be making it more widespread.
from Coronavirus – Wed 18 Mar 2020 – first pass at growth prediction, SARS and MERS
Here’s the timeline knowledge on transmission as best as I could find (I will updated if I get better info):
Table of Contents
1 Feb 2020
Severe acute respiratory syndrome coronavirus 2 > Infection (Wikipedia)
Whether the virus is infectious during the incubation period is uncertain.[34] On 1 February 2020, the World Health Organization (WHO) indicated that “transmission from asymptomatic cases is likely not a major driver of transmission”.[35] However, an epidemiological model of the beginning of the outbreak in China suggested that “pre-symptomatic shedding may be typical among documented infections” and that subclinical infections may have been the source of a majority of infections.[36]
12 Feb 2020
How can the coronavirus spread through bathroom pipes? Experts are investigating in Hong Kong (CNN)
Microbiologist Yuen Kwok-yung said at a Tuesday press conference that an improperly sealed pipe could have resulted in a virus transmission, by carrying infected feces into the building’s ventilation system and blowing it into people’s bathrooms.
“As the pipeline that transfers feces is connected to the air pipe, it is very likely for the virus in the feces to be transmitted through the air fan into the toilet,” Yuen said.
13 Feb 2020
Coronavirus can be spread by people who don’t show symptoms, CDC warns (New York Post)
Dr. Robert Redfield confirmed reports out of China that the virus can spread when the person is still asymptomatic, according to CNN.
“There’s been good communication with our colleagues to confirm asymptomatic infection, to confirm asymptomatic transmission, to be able to get a better handle on the clinical spectrum of illness in China,” Redfield told the outlet. … the discovery is concerning.
18 Feb 2020
Evidence of SARS-CoV-2 Infection in Returning Travelers from Wuhan, China (New England Journal of Medicine)
Published 18 Feb 2020
[On 1 Feb 2020] Two of the 114 persons (1.8%) in this cohort of travelers who had passed the symptoms-based screening tested positive for SARS-CoV-2 … the isolation of SARS-CoV-2 from both samples in cell culture of Caco-2 cells indicated potential infectivity
We discovered that shedding of potentially infectious virus may occur in persons who have no fever and no signs or only minor signs of infection.
23 Feb 2020
5 March 2020
WHO press conference, COVID-19
We know that that is possible, but we do not believe that that’s a major driver of transmission
–Maria Van Kerkhove
17 Mar 2020
How ‘silent spreaders’ are fueling the coronavirus pandemic (Los Angeles Times)
[Public health officials in China] concluded that in the outbreak’s earliest days — between Jan. 10 and Jan. 23 — people well enough to have stayed out of the hospital probably played a key role in the coronavirus’ explosive spread.
18 Mar 2020
Investigating the Impact of Asymptomatic Carriers on COVID-19 Transmission (medRxiv)
Published 18 Mar 2020, posted online 31 Mar 2020
Recent evidence reveals that this sub-population, as well as persons with mild, represent a major contributor in the propagation of COVID-19.
26 Mar 2020
“I want to note that ‘asymptomatic’ is a very swirly definition,” says Shaman, meaning that symptoms are self-reported and, therefore, subjective. But, in general, it means people who do not report feeling sick but do have a proven viral infection.