Influenza activity is minimal in Wisconsin.
The CDC estimates that there have been at least 47 million illnesses, 610,000 hospitalizations, and 26,000 deaths from flu so far this season. Across the U.S. there were 3,531 (5.6%) influenza detections at clinical laboratories, from the 63,566 specimens collected last week. Of detected influenza viruses at public health laboratories, 62.3% were influenza A and 37.7% were influenza B. Among influenza A viruses, 31.6% were H3, 68.4% were H1, and 0% were H5. CDC has reported current match estimates between circulating and vaccine strains for this season (H3: 60%; H1: 99%; B: 99%). The percentage of primary care patients with influenza-like illness (ILI) has decreased to 2.3% and is below baseline. ILI activity is high in 1 state, moderate in 1 state, low in 5 states, and minimal in 43 states; Wisconsin has minimal levels. 204 pediatric deaths (influenza A: 184); influenza B: 11; unknown: 1) have been reported for the 2024-2025 season to date.
Wisconsin has recorded 6,850 hospitalizations for influenza this season. This is well above the total hospitalizations for the entire level in 2023-2024 (3,901).
The performance of rapid influenza testing is lower because of low levels of circulating virus.
The performance of rapid SARS-CoV-2 testing is lower because of low levels of circulating virus.
It is reasonable to stop vaccination against influenza at this time.
There have been 70 confirmed and 7 probable cases (total = 77) detected in 14 states in 2024/2025 as reported by the CDC. Cases have been linked to dairy cattle (42), poultry (29), other animals (2), and unknown (4). There have been 4 hospitalizations and one death due to H5N1. The current public health risk is reported to be low.
A large and growing outbreak of measles is continuing in west Texas and New Mexico. As of April 25, 2025, a total of 884 confirmed measles cases were reported by 30 jurisdictions: Alaska, Arkansas, California, Colorado, Florida, Georgia, Hawaii, Illinois, Indiana, Kansas, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Missouri, Montana, New Jersey, New Mexico, New York City, New York State, Ohio, Oklahoma, Pennsylvania, Rhode Island, Tennessee, Texas, Vermont, Virginia, and Washington; with 94 (11%) hospitalizations and 3 (0.34%) deaths. Most cases (97%) have been unvaccinated or of unknown vaccination status.
For more information on prevention and treatment-
Very low respiratory virus activity has been noted in Wisconsin primary care practices. Rhinoviruses are increasing. For the week ending 4/19/2025, 3.7% of 9,148 specimens tested across Wisconsin by the Wisconsin State Laboratory of Hygiene and clinical labs were positive for SARS-CoV-2. The most commonly identified gastopathogen is norovirus.
Over the past 4 weeks the typical ARI case has been 32.1 years old. 83% of patients have been female. 67% of patients identified a sick contact 1-3 days before illness onset and they typically present to the clinic 11.4 days after illness onset. 40% of illnesses are characterized as mild, with 60% having moderate symptoms and 0% having severe symptoms.
| Viruses in Circulation | Percent* in statewide laboratory surveillance | Percent** in primary care surveillance clinics |
|---|---|---|
| Influenza A | 11.1 | 0 |
| Influenza B | 22.4 | 0 |
| Seasonal Coronavirus*** | 2.6 | 0 |
| RSV | 12.8 | 0 |
| Parainfluenza | 4.7 | 0 |
| hMPV | 6.7 | 0 |
| Rhino/Enterovirus | 16.8 | 0 |
| Adenovirus | 1.5 | 0 |
| Bocavirus | 0.0 | 0 |
| SARS-CoV | 21.4 | 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
SARS-CoV-2 activity is decreasing across Wisconsin.
The 7-day average for patients hospitalized for COVID-19 in Wisconsin is 99 (stable).
SARS-CoV-2 detections have been stable over the past 1 week.
Across Wisconsin, 1,020,508 individuals (17.3% of the population) have received the updated 2024/2025 COVID-19 vaccine.
- 6.6% of all deaths during week 16 (April 13-19) were due to pneumonia, influenza, or COVID-19, and has dropped below the seasonal epidemic threshold.
- Variants: the national proportions of variants for the week ending April 12, 2025, were LP.8.1 (69%); XEC (10%); and LF.7.7.2 (6%). SARS-CoV-2 continues to be a rapidly diversifying virus.
* 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.
