We have done a fair bit of evaluation on COVID-19 in general, but not all of it has made its way to this references page. If you spot any especially relevant gaps or information that is contradictory to any of these links, please let us know, as things are moving quickly and we haven’t had time to credibility check all links.

COVID-19 Disease Progression (and feasibility implications)

Analysis performed up to 2020-03-20


  • There is a period of time before pneumonia is present, suggesting a multi-day progression of initially silent pneumonia that may be detectable.
  • Fever will often, but not always, appear before pneumonia; however fever has a broader range of potential causes. We nonetheless should track fever symptoms at the same time.

COVID-19 Pandemic Progression (and feasibility implications)

Analysis performed up to 2020-03-20


Testing is important and, with a shortage of testing capacity, targeting testing to those with higher probability is key. But, at later stages of the pandemic, community spread limits the effectiveness of targeting by case-tracking.


Long-Term Lung Damage in Recovered Patients


Individuals submitting baselines using Caredemic may help screen those people with potential long-term changes to their lung function, even due to silent pneumonia.

Phone-Based Oximetry (Measuring Blood Oxygen Using Mobile Phone Cameras)


We should explore this further to decide whether or not it should be included in collection.

COVID-19 Impact On Voice

  • Direct anecdote from a respected Mexican doctor: she indicates she can frequently hear a sign of probable COVID-19 in a patient’s voice during regular speech.
  • Carnegie Mellon University has made progress on an app that detects COVID-19 by coughing and talking. Our platform would go several steps further but incorporate their progress.


We can track anonymous usage of vocal cords. Full speech is probably unnecessary; instead we will explore more minimal approaches such as vowel sounds.

Misc Parking Lot of Items The Caredemic Team Is Looking Into

How many days before pneumonia is present in serious cases of COVID-19 (starts 5 days after initial symptoms, which emerge 2.2 -14 days after infection).

Timelines of when each symptom and phase emerges (e.g., asymptomatic lung damage).

(Timeline of normal disease progression from first onset of symptoms, which occurs on average 5 days after infection.) )


Pneumonia Symptoms

  • Dyspnoea (shortness of breath)
    • Median 8 days (IQR 5.0-13.0) Detection method is symptom.
  • ARDS
    • Median 9 days (IQR 8.0-14.0)
  • Mechanical ventilation
    • Median 10.5 days (7.0-14.0)

Symptoms in clinically presenting symptomatic cases

Disease progress

Asymptomatic infection

Differences between Type L (70% of strains in Wuhan) and Type S (Primary strain outside of China)

Coronavirus general


Importance of testing to curbing spread:

  1. [We] cannot stop this pandemic if we don’t know who is infected. We have a simple message for all countries: test, test, test.” – Tedros Adhanom, Director General of the World Health Organization.—16-march-2020
  2. “Testing is very important in terms of identifying cases so epidemiologists can then contact people exposed to individuals who are known to be positive and make recommendations about home isolation and further follow-up,” says Karen Carroll, professor of pathology and director of the Division of Medical Microbiology at Johns Hopkins.”
  3. “When a communicable disease outbreak begins, the ideal response is for public health officials to begin testing for it early. That leads to quick identification of cases, quick treatment for those people and immediate isolation to prevent spread.” – Dr. Eduardo Sanchez, American Heart Association Chief Medical Officer for Prevention


People not taking the symptoms seriously enough:

  1. “There is still considerable uncertainty around the fatality rates of COVID-19 and it likely varies depending on the quality of local healthcare. That said, it is around two percent on average, which is about 20 times higher than for the seasonal flu lineages currently in circulation.” – Francois Balloux, Professor of Computational Systems Biology at University College London.
  2. [With the seasonal flu], when there are enough people in the community who are immune, it protects people who are not immune… That is the case with flu, but not with COVID-19.” – Luis Ostrosky, a member of the Infectious Diseases Society of America
  3. [A] few anti-viral drugs have been developed that blunt the impact of some influenza strains, but no such tool exists for the coronavirus.” – Matt Koci professor of immunology, virology, and host-pathogen interactions at North Carolina State University (edited)


Silent spreading

  1. “The study concluded that 86 per cent of cases were ‘undocumented’ – that is, asymptomatic or had only very mild symptoms.” – Research published last week by Jeffrey Shaman of Columbia University in New York.
  2. “10 per cent of new infections are being spread by either healthy-looking, asymptomatic people or people who have yet to develop the disease’s flu-like symptom. As much as 25 per cent of all U.S. cases [have] remained asymptomatic.” – Robert R. Redfield, Director of the CDC, as quoted in an interview with NPR
  3. “A joint Japanese-U.S.-U.K. study looked at data from the passengers on the Diamond Princess cruise ship who were quarantined for two weeks in Japan after the ship had an outbreak in February. The researchers determined that nearly 18 percent of those who were infected never showed symptoms.”


Shortage of testing

  1. “We do not have a capacity, and we will not have the capacity in the short or medium term to test every [person] who has a cough or a runny nose.” – Dr. Deena Hinshaw, chief medical officer of health for the province of Alberta, Canada.
  2. “Testing is essential for identifying people who have been infected and for understanding the true scope of the outbreak. But…academic, clinical, and other laboratories have struggled to get or make new tests and diagnose patients.”