COVID-19: Wisconsin Cases

About our data

All data are laboratory-confirmed cases of COVID-19 that we extract from our live Wisconsin Electronic Disease Surveillance System (WEDSS) and freeze once a day. These numbers are the official state numbers, though counties may report their own totals independent of DHS. Combining the DHS and local totals may result in inaccurate totals.

Deaths must be reported by health care providers, medical examiners/coroners, and recorded by local health departments in order to be counted.

The number of people with negative test results includes only Wisconsin residents who had negative test results reported electronically to DHS or entered manually into the WEDSS electronic laboratory module. As a result, this number underestimates the total number of Wisconsin residents with negative test results.

Data shown below are subject to change. We strive for transparency and accuracy in our data, and as individual cases are investigated by public health, there may be corrections to the status and details of cases that result in changes to this information. Some examples of corrections or updates that may lead to changes to our data, such as case and negative counts and deaths going up or down, include: 

  • Update or correction of case's address, resulting in a change to their location of residence to another county or state,
  • Correction to laboratory result,
  • Correction to a case's status from confirmed to unconfirmed (for example, if they were marked as confirmed because a blood test detecting antibodies was positive instead of a test detecting the virus causing COVID-19),
  • De-duplication or merging and consolidation of case records,
  • Update of case's demographic information from missing or unknown to complete information.

For information on testing, see: COVID-19, testing criteria section

Wisconsin and surrounding states and Great Lakes map image

View COVID-19 Maps

Download the following data:

Need more information? Look at our Data Dictionary (PDF) or visit our Data 101 section where you can find information on how we calculate and report COVID-19 data.







What is a COVID-19 probable case?

A person is counted as a probable case of COVID-19 if they are not positive by a confirmatory laboratory test method* (for example, a PCR or molecular test), but have met one of the following:

  1. Test positive using an antigen test method
  2. Have symptoms of COVID-19 AND known exposure to COVID-19 (for example, being a close contact of someone who was diagnosed with COVID-19)
  3. COVID-19 or SARS-CoV-2 is listed on the death certificate

A detailed surveillance case definition for COVID-19 probable cases (used by public health and not to be used for making diagnostic or clinical decision) is available under Reporting and Surveillance Guidance on the COVID-19 Health Care Providers webpage.

*This definition was updated as of August 19, 2020. Previously, probable cases also included those had a positive antibody test which detects COVID-19 antibodies in the blood. For more details on this transition, see the CDC’s statement.



Percent of COVID-19 cases by hospitalization status

Percent of COVID-19 cases living in group housing

Long-term care facilities include skilled nursing facilities (nursing homes) and assisted living facilities (community-based residential facilities and residential care apartment complexes).

Group housing facilities include correctional facilities, homeless shelters, dormitories, and group homes.

The data on group housing is unknown at this time for a portion of cases because these data have only been systematically collected since April 8, 2020. However, any COVID cases who were part of an outbreak investigation in a long-term care or other group housing facility prior to April 8 are classified under the appropriate group setting category (and are not included in the unknown category).

Percent of COVID-19 cases by recovery status

The number of patients recovered from COVID-19 is defined as the number of confirmed cases who are currently alive based on Wisconsin state vital records system data and had one or more of the following:

  • Documentation of resolved symptoms
  • Documentation of release from public health isolation
  • 30 days since symptom onset or diagnosis*

Active cases include COVID-19 cases who were diagnosed in the last 30 days, are not known to have died, and do not yet meet the definition of having recovered.

*Our data indicate that the vast majority of reported cases who recovered did so within 30 days. Rarely, more than 30 days were required to recover. As a result, a very small number of cases who are still recovering might be included in the 'Recovered' category.

Percent of COVID-19 cases who are health care workers

Data on COVID-19 cases who are health care workers represents a broad range of occupations in the health care field, including nurses, physicians, surgeons, physician assistants, health care support staff, emergency medical technicians and paramedics, dentists and other dental health workers, and pharmacists.


Last Revised: September 21, 2020