From Wisconsin Division of Public Health:
Health Care Personnel Exclusion and Return to Work Following an Acute Respiratory Illness
https://www.dhs.wisconsin.gov/dph/memos/communicable-diseases/2025-04-bcd.pdf
Influenza has arrived and is rising significantly in Wisconsin. Levels of rhinovirus are declining. Rates of influenza-like illnesses (ILI) in Wisconsin outpatients are increasing.
Across the U.S. there were 4,790 (8.1%) influenza detections at clinical laboratories, from the 59,364 specimens collected last week. Of detected influenza viruses at public health laboratories last week, 96.0% were influenza A and 4.0% were influenza B. Among influenza A viruses, 86.0% were H3, 14.0% were H1, and 0% were H5. Of genotyped viruses, 89.0% of AH3 viruses are from subclade K. CDC has reported current match estimates between circulating and vaccine strains for this season (H3: 9%; H1: 100%; B: 86%). The percentage of primary care patients with influenza-like illness (ILI) is at 3,2% and is above baseline. ILI activity is high in Colorado, Louisiana, New Jersey and New York; moderate in 8 states, low in 13 states, and minimal in 25 states; Wisconsin has minimal levels. One pediatric death due to influenza A has been reported for the 2025-2026 season to date.
A recent paper describes the emergence of subclade K and the prolonged influenza season in Australia and New Zealand: https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2025.30.49.2500894
The use of rapid influenza testing is improving at this time based on increasing levels of circulating virus. Use of rapid COVID-19 testing is reasonable, and positive results do not need confirmation.
The most common viral causes of acute respiratory infections in Wisconsin primary care practices are rhinoviruses. For the week ending December 1, 2025, 3.7% of 6,073 specimens tested across Wisconsin and compiled by the Wisconsin State Laboratory of Hygiene were positive for SARS-CoV-2. The most commonly identified gastopathogen is norovirus.
Over the past 4 weeks the typical ARI case has been 56.1 years old; 67% of patients have been female. 25% of patients identified a sick contact 1-3 days before illness onset and they typically present to the clinic 5.3 days after illness onset. 50% of illnesses are characterized as mild, with 50% having moderate symptoms and 0% having severe symptoms.
| Viruses in Circulation | Percent* in statewide laboratory surveillance | Percent** in primary care surveillance clinics |
|---|---|---|
| Influenza A | 6.4 | 0 |
| Influenza B | 0.0 | 0 |
| Seasonal Coronavirus*** | 1.2 | 0 |
| RSV | 9.3 | 0 |
| Parainfluenza | 8.7 | 0 |
| hMPV | 0.8 | 0 |
| Rhino/Enterovirus | 33.6 | 100 |
| Adenovirus | 2.4 | 0 |
| Bocavirus | 0.0 | 0 |
| SARS-CoV | 37.5 | 0 |
*estimate based on WSLH statewide data
** estimate based on primary care patients seen at five clinics in Dane County
*** includes HKU1, NL63, 229E and OC43
Wisconsin: The 7-day average rate for patients hospitalized for COVID-19 in Wisconsin is 1.2/100,000. This compares to rates for influenza 1.2/100,000 and RSV at 0.4/100,000.
COVID-19 Vaccine: Across Wisconsin, 629,655 individuals (10.6% of the population) have received the updated 2025/2026 COVID-19 vaccine.
COVID-19 Wastewater Surveillance: COVID-19 levels for Wisconsin are very low and increasing.
Please refer to guidance provided by Wisconsin Department of Health Services, available at:
https://www.dhs.wisconsin.gov/covid-19/providers.htm
and by the U.S. Centers for Disease Control and Prevention, available at:
* The weekly influenza update is adapted from an email from Jon Temte, MD, PhD; Chair, Wisconsin Council on Immunization Practices; Professor, Department of Family Medicine and Community Health, University of Wisconsin School of Medicine and Public Health.
