FOR IMMEDIATE RELEASE: May 23, 2020

CONTACT: Bob Wheaton, 517-241-2112

LANSING, MICH. The Michigan Department of Health and Human Services (MDHHS) today changed the way it reports data on COVID-19 testing.

The change makes the data more accurate and relevant as the state continues to expand diagnostic testing to help slow and contain the spread of COVID-19. The update to the website separates out the results of two different types of tests – serology and diagnostic. Michigan – along with some other states – has not separated data for diagnostic and serology tests.

Data on serology testing – also known as antibody testing – is separated from the other testing numbers. Currently, serology testing can be used to help determine whether someone has ever had COVID-19, while traditional viral diagnostic tests determine if someone has active disease.

“Accuracy and transparency are paramount as we continue to respond to this pandemic,” said Dr. Joneigh Khaldun, chief medical executive and chief deputy for health. “We continue to expand and improve data reporting to make sure the public understands where their community stands with the COVID-19 outbreak.”

MDHHS emphasizes that the change in reporting does not affect the number of lab-confirmed COVID-19 cases in Michigan. It does lower the percentage of positive tests over the last nine days – when serology testing became more common. Michigan’s overall percentage of positive tests since the beginning of the outbreak remains virtually the same – changing from 14.2 percent positive tests to 14.3 percent.

Michigan’s COVID-19 website now shows results for 512,891 total tests reported to the state – with 450,918 diagnostic test results and 61,973 serology results.

Diagnostic tests are most helpful in tracking the spread of COVID-19 since they can show the number of people who currently have the COVID-19 virus. Serology tests are still being studied regarding their utility.  They are currently most helpful in understanding how much a community may have been exposed to the disease. However, it is unknown if the presence of an antibody truly means someone is immune to COVID-19, and if so, for how long. Results of antibody tests should not change decisions on whether an individual should return to work, or if they should quarantine based on exposure to someone with the disease.

Approximately 12 percent of Michigan’s tests overall have been serology tests; about 60 percent of those have been from the past nine days.

Testing data can be found on the Lab Testing page of Michigan’s coronavirus website.

Information around the COVID-19 outbreak is changing rapidly. The latest information is available at Michigan.gov/Coronavirus and CDC.gov/Coronavirus.