Public Health Madison & Dane County

Reportable Disease Data

Dashboard Update Schedule

This report will be updated quarterly (four times per year). The date of the most recent update can be found in the lower-left corner of the homepage. 

Dashboard Data Notes

Last updated January 2024

Purpose of the Dashboard

The purpose of this dashboard is to provide Dane County-specific communicable disease data to health care providers, community partners, and people who live in Dane County. People could use this data for a variety of purposes, such as:

  • Informing clinical testing decisions
  • Informing prevention actions at organizations or businesses
  • Informing personal health actions
  • Using data for reports and grant applications

Data Source

  • The diseases included on this dashboard are communicable diseases that are reportable in Wisconsin. Reportable diseases are considered to have significant public health impact. Most reports come from health care providers and laboratories, but schools, child care centers, long-term care facilities, blood and plasma donation centers, and workplaces also report communicable diseases. The list of Wisconsin's reportable diseases can be found in Wisconsin Administrative Code Chapter DHS 145 Appendix A, with general reporting requirements described in Wisconsin Statutes Chapter 252 and specific reporting requirements in Wisconsin Administrative Code Chapter DHS 145.
  • All data for this dashboard are from the Wisconsin Electronic Disease Surveillance System, or WEDSS. Most health care providers and laboratories in Dane County report communicable diseases though WEDSS, a secure web-based system which is used by all local and tribal health departments in Wisconsin. When we receive reports by mail, fax, or phone, we also enter them into WEDSS. The details for each case are stored in WEDSS.
  • HIV data are received from the Wisconsin Department of Health Services HIV Program. The HIV cases reported on the dashboard have been determined to be new HIV diagnoses. Data are provisional and subject to change as additional information becomes available. For more HIV data, see the HIV Program Data website.

Data Included

Counts of people diagnosed with a reportable disease who live in Dane County are included in the dashboard. Only people whose disease diagnosis meets the “confirmed" or “probable" case definitions are included on the dashboard, except for latent tuberculosis infection.

Wisconsin has case definitions for each reportable disease, most of which were adopted from the Council of State and Territorial Epidemiologists, a national organization that develops case definitions, which are adopted by the CDC and most states. Case definitions ensure that cases are counted in the same way across Wisconsin and the United States. To find Wisconsin's case definitions, you can go the Wisconsin Department of Health Services disease reporting website and click on a disease. On each disease's website, there is a “Case Reporting and Investigation Protocol (EpiNet)" that has that disease's reporting requirements and case definitions (it may be located within a section for Health Professionals or Reporting and Surveillance).

All diseases have a “confirmed" case definition, and some may also have a “probable" and/or “suspect" case definition. In general, “confirmed" case definitions require that a person has a positive result for a specific lab test and may also include specific symptoms. “Probable" case definitions often include symptoms, and/or a link to another person with the same infection. “Suspect" cases may have symptoms but not a positive lab or a positive result on a less specific lab test. Part of our communicable disease follow-up is to collect data to determine which case definition a person meets. We follow nationally-validated case definitions so that our data are comparable to state and national counts of the same disease. 

Latent tuberculosis infection is the only reportable condition on the dashboard that may not always meet the “confirmed" or “probable" case definition. Including data from “suspect" cases is important because these people do have tuberculosis infection and it is most likely latent (no symptoms, not contagious). If a person has latent tuberculosis that progresses to active tuberculosis, they will develop symptoms and become contagious. 

If a reportable disease is not listed on the dashboard, it means there have been no confirmed or probable cases in Dane County since January 1, 2019.

We use the “date created" date in WEDSS to determine which month and year a case falls in. The date created is the date the case was reported to WEDSS. Because most cases are initially reported to WEDSS when the lab result automatically comes into WEDSS, the date created will most often correspond to the date the lab result was generated and this date created is generally close to when the person became ill. Occasionally, we'll receive reports weeks or months after the person was sick, which could count them in a month well after they became ill, but this is rare. There are numerous other dates in WEDSS, such as illness onset date, laboratory test date, and the date the report was received. Other organizations may use one of these other dates to count cases, which can result in slightly different counts. Data in the dashboard go back to January 1, 2019.

Dashboard Update Schedule

The dashboard will be updated quarterly, on the third Thursday of January, April, July, and October. Each quarter, data will be added for the preceding three months and data for previous months in the same year will be updated as applicable. In January and April, data for the preceding year will also be updated as applicable. In July, the data for the previous year will be finalized. The Ten Most Common Reportable Illnesses section will be updated each July.

Data Changes

Numbers may change from quarter to quarter for several reasons. Sometimes it takes weeks or months for additional testing that may result in the case changing from “suspect" to “probable" or “confirmed." It may take a while to reach a person to find out what their symptoms were. Also, as staff at the Wisconsin Department of Health Services review cases, a case's status may change. 

Data Interpretation and Context

Increases and decreases on the dashboard can be a result of many things: a real change in the incidence of the disease, a change to the case definition impacting how the disease is counted, a change in testing practices, or other reasons. With Dane County's population growth, some illnesses may see increases simply because there are more people living in our community. It's important to dive into the context when studying these data. When we have information about an outbreak or alarming trend, we'll send out additional context in our quarterly newsletter. If you have questions about the ‘why' behind a trend, reach out to us: epi@publichealthmdc.com. 

Data Availability

To obtain data in table format, click on the three dots in the upper right-hand corner of each chart to view the data in table format. If you need something else, submit a data request on our website. We may also be able to provide additional details, such as demographic data or a wider range of years.

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