As the coronavirus pandemic spreads, we've asked readers what they most want to know about its impact, prevention and treatment. This is an answer to one of those questions. You can find more answers here.


Given limited testing, does anyone know the real number of COVID-19 cases in Minnesota?

It has been clear for some time that the official COVID-19 case counts don’t reflect the actual number of people who have been sickened by the new coronavirus.

First, there was a shortage of test kits, then continuous waves of shortages of chemicals needed to process the tests, the swabs needed to take samples and the masks and protective gear needed to protect the health care workers collecting the sample.

When researchers at the Minnesota Health Department and the University of Minnesota School of Public Health took on the task of projecting the impact that COVID-19 would have on hospital resources and human life, they assumed that 12 percent of all infections had been detected through testing.

But when they looked at the number of people that had already died in Minnesota, the numbers didn’t quite add up, especially given new research that shows that one infected person can pass the disease on to as many as four others.

Now they estimate that the case detection rate is more like 1 percent.

“Multiply the number of confirmed cases by 100, and that is where we expect to be,” said Stefan Gildemeister, health care economist at the Minnesota Health Department. “The epidemic is much more widespread than would be apparent.”

That means that on April 22, with 2,721 confirmed cases in Minnesota through laboratory testing, there actually could be more than 272,000 infected people in the state. That would mean that roughly 4.8% of the population has been infected with the new coronavirus.

However, those are estimates and the state hopes to fill the knowledge gap through new antibody testing which will help researchers better understand the infection rate.

Because of the lack of diagnostic testing, most testing has been directed to people with severe infections who are in the hospital, as well as those in long-term care facilities and health care workers.

For people with mild symptoms, which constitute nearly 80% of all cases, diagnostic testing is not necessary as there is no treatment for COVID-19. Even with a test, a doctor would recommend the same actions as someone who had the flu or a severe cold: stay at home, get rest, drink fluids and try not to infect others.

Even with seasonal influenza, public health officials don’t know how many people actually get the flu each season. They monitor hospitalizations and deaths and get reports from clinics across the state that help paint a picture of how each season is unfolding.

But with COVID-19 being more infectious and deadly than the flu, Minnesota officials recently announced plans to expand testing in cooperation with the University of Minnesota and the Mayo Clinic. The goal is to ramp up capacity to do 20,000 diagnostic and 15,000 antibody tests per day.

DATA: See our complete COVID-19 tracking page for Minnesota, the U.S.