New Wisconsin Department of Health Services Respiratory Virus Data
Influenza activity is currently at low levels in Wisconsin. Other than SARS-CoV-2, we are seeing significant levels of rhinovirus and parainfluenza viruses. Rates of influenza-like illnesses (ILI) in Wisconsin outpatients are considered low.
Data for US Surveillance from CDC have not been available since September 20, 2025. Influenza cases across Australia were about 70% A(H1), 20% B/Victoria, and 10% A(H3). There was, however, the emergence of an A(H3) variant (subclade K: https://nextstrain.org/seasonal-flu/h3n2/ha/2y) which took off across Australia at the end of the season. According to my source, this may be a pretty fit virus and may have quite a run in the Northern Hemisphere for the winter!
The use of rapid influenza testing is tenuous at this time based on low levels of circulating virus. RIDT(+) results should be confirmed using RT-PCR. Use of rapid COVID-19 testing is reasonable, and positive results do not need confirmation.
In case you need more evidence to vaccinate: Influenza, SARS-CoV-2, HIV, hepatitis C virus, and herpes zoster were associated with an increased risk of major cardiovascular events. Vaccines may play an important role in preventing the risk of cardiovascular disease. [See: Kawai K et al. Viral Infections and Risk of Cardiovascular Disease: Systematic Review and Meta-Analysis. J Am Heart Assoc. 2025 Oct 29:e042670. doi: 10.1161/JAHA.125.042670. Epub ahead of print. PMID: 41160032.]
The most common viral causes of acute respiratory infections in Wisconsin primary care practices are rhinoviruses and parainfluenza viruses. For the week ending October 27, 2025, 2.5% of 7,376 specimens tested across Wisconsin and compiled by the Wisconsin State Laboratory of Hygiene were positive for SARS-CoV-2. The most commonly identified gastopathogens are norovirus and Campylobacter.
Over the past 4 weeks the typical ARI case has been 15.3 years old; 88% of patients have been female. 33% of patients identified a sick contact 1-3 days before illness onset and they typically present to the clinic 3.7 days after illness onset. 33% of illnesses are characterized as mild, with 67% having moderate symptoms and 0% having severe symptoms.
| Viruses in Circulation | Percent* in statewide laboratory surveillance | Percent** in primary care surveillance clinics |
|---|---|---|
| Influenza A | 8.8 | 0 |
| Influenza B | 0.0 | 0 |
| Seasonal Coronavirus*** | 0.1 | 0 |
| RSV | 0.9 | 0 |
| Parainfluenza | 9.1 | 33 |
| hMPV | 1.0 | 0 |
| Rhino/Enterovirus | 51.7 | 67 |
| Adenovirus | 1.6 | 0 |
| Bocavirus | 0.0 | 0 |
| SARS-CoV | 26.8 | 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 0.6/100,000. This compares to rates for influenza 0.1/100,000 and RSV at 0.0/100,000.
COVID-19 Vaccine: Across Wisconsin, 454,381 individuals (7.6% of the population) have received the updated 2025/2026 COVID-19 vaccine.
COVID-19 Wastewater Surveillance: COVID-19 levels for Wisconsin are very low.
COVID-19 and Autism: Maternal SARS-CoV-2 infection in pregnancy was associated with increased risk of adverse neurodevelopmental diagnoses by age 3 years, with effects most pronounced after third-trimester exposure and in male offspring.
[See: Shook LL yet al. Neurodevelopmental Outcomes of 3-Year-Old Children Exposed to Maternal Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection in Utero. Obstetrics & Gynecology ():10.1097/AOG.0000000000006112, October 30, 2025. | DOI: 10.1097/AOG.0000000000006112]
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.
