Influenza is at low levels in Wisconsin.
Across the U.S. there were 739 (1.3%) influenza detections at clinical laboratories, from the 57,221 specimens collected last week. Of detected influenza viruses at public health laboratories last week, 94.8% were influenza A and 5.2% were influenza B. Among influenza A viruses, 43.8% were H3, 52.4% were H1, and 3.8% were H5. CDC has reported current match estimates between circulating and vaccine strains for this season (H3: 75%; H1: 96%; B: 100%). The percentage of primary care patients with influenza-like illness (ILI) is at 2.5% and is below baseline. ILI activity is low in 6 states and minimal in 44 states; Wisconsin has minimal levels. One pediatric death, due to influenza A, has been reported for the 2024-2025 season to date.
Wisconsin has recorded 27 hospitalizations for influenza this season. This is below the level in 2023-2024 (34) at this point.
The performance of rapid influenza testing is reduced because of low levels of circulating virus.
The performance of rapid SARS-CoV-2 testing is reduced because of declining levels of circulating virus.
7 human infections with influenza A(H5) virus were reported to CDC this week; there have been 46 cases detected in the U.S. in 2024. A human A(H5N1) case (adolescent in critical condition) has been reported from British Columbia, CANADA. There are no known exposures.
As of November 8, 2024, Wisconsin has 1,596 confirmed cases statewide (age range: 1 month—83 years), with detections in 64/72 counties. 48% of the cases have been in individuals aged 11–18 years. 69 infants have been identified with pertussis and 10 have been hospitalized. No deaths have been reported. The percent positive rate for specimens submitted for pertussis tests is elevated at 2.4%.
Viruses associated with acute respiratory infections in Wisconsin primary care practices have been dominated by Rhinovirus. For the week ending 11/02/2024, 6.0% of 9,806 specimens tested across Wisconsin by the Wisconsin State Laboratory of Hygiene and clinical labs 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 39.5 years old. 67% of patients have been female. 20% of patients identified a sick contact 1-3 days before illness onset and they typically present to the clinic 9.6 days after illness onset. 20% of illnesses are characterized as mild, with 80% having moderate symptoms and 0% having severe symptoms.
| Viruses in Circulation | Percent* in statewide laboratory surveillance | Percent** in primary care surveillance clinics |
|---|---|---|
| Influenza A | 9.0 | 0 |
| Influenza B | 0.8 | 0 |
| Seasonal Coronavirus*** | 0.9 | 0 |
| RSV | 2.8 | 0 |
| Parainfluenza | 6.2 | 0 |
| hMPV | 1.6 | 0 |
| Rhino/Enterovirus | 21.0 | 100 |
| Adenovirus | 1.8 | 0 |
| Bocavirus | 0.0 | 0 |
| SARS-CoV | 56.1 | 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
The 7-day average for patients hospitalized for COVID-19 in Wisconsin is 125 (stable).
There has been a slight decrease over the past 1 week.
Across Wisconsin, 623,561 individuals (10.5% of the population) have received the updated 2024/2025 COVID-19 vaccine.
Please refer to guidance provided by Wisconsin Department of Health Services and by the U.S. Centers for Disease Control and Prevention.
* 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.
