Toronto 
Cases as of April 7, 2020, 6:46 p.m. EDT/ Credit: Canada.ca
It is a known fact that Canada is not testing everybody who has COVID-19 like symptoms. Currently, many provinces are only testing the highest priority patients, like the health-care workers.
As of April 7, 2020, according to the Public Health Canada website, Canada has carried out 348,105 tests and has a total of 17,897 positive reported cases.
In order to estimate an approximate number of Canadians outside the hospital system who have been infected with novel coronavirus, Angus Reid Institute conducted a survey involving a representative sample of more than 4,200 Canadians.
The survey asked participants to record any new symptoms (excluding those that might have been part of a chronic condition) they had experienced from a list of eight symptoms (sore throat, a mild dry cough, frequent sneezing, difficulty breathing, a fever, a severe disruptive dry cough, loss of sense of smell, fever with hallucinations, no symptoms) over the month of March. Those living in households with more than one occupant were also asked if any others in the household had experienced these symptoms.
From the responses received, Angus Reid Institute narrowed the data to those having both fever and respiratory distress. This data was then superimposed with seasonal influenza data, results from those who received the COVID-19 tests within the survey respondents, a 20 per cent infection rate and a baseline of 25 per cent asymptomatic infection.
Credit: Angus Reid Institute
Combining all these, Angus Reid Institute estimates that there are 147,900 Canadian households where COVID infection was or is present.
Though it is impossible to know whether the survey results are reflective of the true number of cases in Canada, ARI poll stresses the importance of social distancing since the likelihood of being in contact with someone carrying this virus is ten times greater than if there are only 10,000 with COVID-19.
The detailed survey results and the methodology can be found here.
