Skip to navigation Skip to Content

Search

Menu
Search Marshfield Clinic Health System
Join a world-class health system. Find jobs

Marshfield Clinic Research Institute contributes data, lab testing for CDC study on household flu transmission surge during pandemic

​​Jan. 26, 2023

MARSHFIELD – Marshfield Clinic Research Institute was a key part of a Centers for Disease Control and Prevention-led study that found household spread of flu during the second flu season of the COVID-19 pandemic was more than twice as high as it was prior to the pandemic.

The CDC study published Thursday in the Journal of the American Medical Association looked at household flu transmission in the two flu seasons prior to the COVID-19 pandemic and the 2021-22 flu season among cohorts in four states, including Wisconsin.

During the 2021-22 season, 50% of household contacts of a patient with flu were themselves infected within seven days after the first person became sick, compared with 20% of household contacts during two flu seasons before the COVID-19 pandemic. The secondary spread of flu in the household setting estimated during the 2021-22 season was also higher than estimates reported from previous flu household transmission studies.

“This study highlights the need for household measures to prevent flu transmission, and the importance of annual flu vaccination to reduce the risk of flu illness," said Research Scientist Huong McLean, Ph.D., one of the study's authors and the local principal investigator.

Potential reasons for the higher levels of household spread of flu during the 2021-22 season compared to previous seasons include:

  • Antibodies against flu may have declined or waned as a result of lower levels of flu circulation in the two years after the start of the COVID-19 pandemic.
  • Reductions in seasonal flu vaccination among children during the COVID-19 pandemic may have contributed to increased population susceptibility.
  • Social interactions in the United States changed during the COVID-19 pandemic, with people generally spending more time at home, potentially raising the risk of household transmission.

All pre-pandemic study participant enrollments were done through Marshfield Clinic Research institute and Vanderbilt University. MCRI's Integrated Research & Development Laboratory performed laboratory testing to identify influenza cases in the pre-pandemic seasons.

Joining McLean as authors of the study were Epidemiologist Dr. Ed Belongia, M.D.; and Jennifer Meece, Ph.D., Director of Integrated Research & Development Laboratory and MCRI interim executive director.​

​​

 Media Relations

John Gardner
Marshfield Clinic Health System Director of Communications
715 221-8659
gardner.john
@marshfieldclinic.org

Jeff Starck
Senior Media Relations Specialist - Marshfield, Eau Claire, Ladysmith, Minocqua, Neillsville, Park Falls, & Rice Lake
715 389-4978
starck.jeffrey
@marshfieldclinic.org

Dan Baulch
Senior Communications
Specialist -
Beaver Dam
920 887-4152
baulch.dan
@marshfieldclinic.org

Jim Korth
Communications Specialist – Wausau/Weston
715-679-5455
korth.james
@marshfieldclinic.org

Joe Rizzo
Director of Public Relations and Business Development –
Marshfield Medical
Center-Dickinson
906-776-5671
Joe.Rizzo@dchs.org