Influenza Update

UPDATED: April 30, 2021

Wisconsin continues to experience extremely low influenza activity at present.  Other than SARS-CoV-2, the only other virus we are seeing in any abundance is rhinovirus.  Wisconsin has recorded no influenza deaths for the 2020-2021 season.


Across the U.S. there have been 243 (0.06%) influenza detections at public health laboratories, from 438,098 specimens, since September 27, 2020 (this is incredibly low).  Of detected viruses, 61% have been influenza A and 39% have been influenza B.  The percentage of primary care patients with influenza-like illness has not risen above baseline and there has been only one pediatric influenza-associated death reported in the U.S. this season. 

Primary Care Snapshot

The most commonly identified viral cause of acute respiratory infections in Wisconsin is SARS-CoV-2.  For the week ending April 19, 2021, 4.2% of 72,540 specimens tested at the Wisconsin State Laboratory of Hygiene and clinical labs were positive for SARS-CoV-2.

Viruses in Circulation*Percent
Influenza A0.0
Influenza B0.0
Seasonal Coronavius**0.1
*estimate based on WSLH statewide data
** includes HKU1, NL63, 229E and OC43

SARS-CoV-2 Cases

As of today, 150,640,276 global cases have been confirmed, with 3,168,705 reported deaths (CFR = 2.1%).  There have been 32,290,529 laboratory-confirmed cases reported in the United States with 575,200 deaths (CFR = 1.8%).  Closer to home, there have been 597,258 confirmed cases in Wisconsin (an increase of 20,163 cases from last report), with 6,815 deaths (an increase of 193 deaths from last report; CFR = 1.1%).  Please note that the CFRs reported here are crude and based only on laboratory confirmed cases.


We are seeing a slight increase in SARS-CoV-2 transmission.  The 7-day average for patients hospitalized for COVID-19 in Wisconsin is 351 and a 7-day v=average of 112 (32%) requiring intensive care.

Wisconsin’s 14-day Trend

Over the past 14 days, there has been an increase in the growth rate of new cases per day (2.4 more cases each day).

COVID-19 Vaccine

Wisconsin’s COVID-19 vaccine rollout is underway with 4,248,455 doses allocated, and 4,363,653 doses administered as of 4/27/2021.  Across Wisconsin, 1,929,913 individuals (33.1% of the population) are now fully vaccinated. 

Across the US:

- The overall cumulative rate for COVID-19 hospitalization across the U.S. is 531.5/100,000 (one admission for every 188 people). 


- The overall cumulative death rate for COVID-19 across the U.S. is 175.4/100,000 (one death for every 570 people). 


-11.8% of deaths during week 16 (April 18-24) were due to pneumonia, influenza or COVID-19.


Please refer to guidance provided by Wisconsin Department of Health Services, available at:

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.

Sign up to the
WAFP Email List