Wisconsin DHS Health Alert #35: Increased Influenza Identified in Midwest Universities

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DHS Health Alert Network

Wisconsin DHS Health Alert #35: Increased Influenza Identified in Midwest Universities

Bureau of Communicable Diseases

November 30, 2021

Key Points

  • Increased influenza activity and large outbreaks have been reported among college and university students in Midwest states, including Wisconsin.
  • Overall, seasonal influenza activity remains low in Wisconsin and across the United States, but is expected to increase in the coming weeks.
  • Wisconsin health care providers and public health partners should review the 11/24 Centers for Disease Control and Prevention (CDC) Health Advisory for important information about testing and treatment of seasonal influenza.
  • Now is the time to escalate efforts to promote influenza vaccination for all Wisconsin residents 6 months of age and older who have not yet received their annual influenza shot. All influenza vaccines can be co-administered in the same visit with COVID-19 vaccines.


On November 24, the CDC issued a Health Alert Network Health Advisory describing increasing seasonal influenza A (H3N2) activity in the United States, especially among young adults and in college and university settings.

The recent outbreaks and associated increasing detection of influenza A/H3N2 viruses are notable because they represent the first significant influenza activity of the 2021-2022 season and the first activity since March 2020. Historically, seasons where influenza A/H3N2 is the predominant virus results in higher morbidity and an increase in outbreaks, especially among the older population, young children, and those living in congregate settings.

On college campuses, influenza viruses are known to spread rapidly in close quarters (e.g., common living spaces, classrooms, shared restrooms) and through social activities. Young adults, including college and university students, consistently have the lowest influenza vaccination coverage every influenza season in the United States.


The Wisconsin Department of Health Services (DHS) recommends that all people aged six months and older who do not have a medical contraindication receive the influenza vaccine. This recommendation includes vaccinating university students and staff. Offer vaccination now while influenza rates are low and throughout the season for as long as influenza is circulating.

Influenza vaccination will help prevent influenza illness symptoms that may be confused with COVID-19, helping reduce the burden on the healthcare system caused by healthcare visits and hospitalizations related to influenza.

Use of Antiviral Medications for Treatment and Post Exposure Prophylaxis

CDC recommends influenza antiviral medications to treat influenza as an important adjunct to vaccination. Influenza antivirals benefit clinical and public health by reducing illness and severe outcomes of influenza. Antiviral treatment is recommended as soon as possible for patients with suspected or confirmed influenza who are:

  • Hospitalized
  • Outpatients at increased risk for complications
  • Outpatients with progressive disease

CDC also recommends using clinical judgment for antiviral post-exposure prophylaxis for certain exposed non-ill close contacts of persons with suspected or confirmed influenza. Given the unique considerations of influenza outbreaks in various settings in the context of co-circulation with SARS-CoV-2, influenza antiviral PEP might be considered for persons who:

  • Have had recent close contact with a person with influenza (e.g., roommates)
  • Reside in confined quarters (e.g., dormitories, shelters, prisons) with increasing incidence of influenza
  • Are at increased risk for severe illness from influenza
  • Had recent close contact with a person with influenza and will be traveling for the holidays to reduce transmission during travel as well as to reduce transmission to family members or friends who may be at higher risk for influenza complications

Laboratory Testing

Symptoms of influenza and COVID-19 are similar. Symptomatic patients should be tested for both SARS-CoV-2 and influenza, preferably using an RT-PCR test for diagnosis. Establishing a definitive diagnosis for influenza and/or COVID-19 can facilitate prompt initiation of appropriate treatment and infection control measures.

Travel Precautions

Exercise caution traveling between universities and out of state, especially for upcoming sporting and recreational events, and traveling for holiday gatherings. Persons with respiratory symptoms consistent with COVID-19 or influenza should avoid or delay travel.

Reporting of Influenza Outbreaks

Individual cases of influenza are not reportable. To report a suspected influenza outbreak or for other influenza-related questions, including consultation and specimen testing authorization, please contact the local health department where the college or university is located. 

Links to Additional Information

CDC: Information for Clinicians on Influenza Virus Testing

CDC: Influenza Antiviral Medications: Summary for Clinicians

CDC: Interim Guidance for Influenza Outbreak Management in Long-Term Care and Post-Acute Care Facilities

Thank you for your attention and collaboration.


Ryan Westergaard, MD, PhD, MPH Chief Medical Officer and State Epidemiologist for Communicable Diseases Wisconsin Department of Health Services