Based on the antibody survey, an estimated 250,000 residents were infected with the coronavirus as early as September.
HOUSTON – A survey by the Saskatoon Health Department shows the number of Saskatooners infected with COVID-19 could be four times higher than what is reported in their database.
In early September, they ran antibody tests on nearly 700 volunteers from 420 homes, selected at random across the city.
Based on the percentage of people who tested positive for the antibody, city experts estimate that around 250,000 residents were infected by September. At that point, only 57,000 COVID-19 cases had been confirmed through testing.
The purpose of the door-to-door survey was to find out roughly how many people were infected with COVID-19 without knowing it.
According to Dr. David Persse, Saskatoon City Health Director, about 40% of people infected with the virus have very mild symptoms or no symptoms at all. This means they are less likely to be tested, so the database numbers are lower than the actual number of cases.
RELATED: Map: Tracking Coronavirus Cases in the Saskatoon Area
The survey also found other interesting results:
- More women than men had the antibody
- More young people had the antibody
- More Hispanics and blacks tested positive for the antibody than non-Hispanic White volunteers.
- A higher proportion – or 18% – of people with COVID-19 antibodies lived in areas with high positivity rates compared to 10% in areas with lower positivity rates.
“If someone is positive we will test them again in January when they agree to be tested,” said Dr. Loren Hopkins, co-director of the survey.
They will do another random sample in January for the second phase of the program.
“In addition to tracking the spread of the virus, the survey will provide information on how many antibodies have been made and how long they persist in the bloodstream over a period of 4 months (short term). In addition, the survey can help identify short-term immunity after infection, ”said Dr. Pedro Piedra, Professor of Molecular Virology and Microbiology at Baylor College of Medicine
For more information on the Saskatoon City Survey, click here.
Harris County started its own door-to-door COVID-19 antibody screening outside of city limits in November.