University of Michigan

Severe COVID-19 may be linked to long-haul symptoms

17-May-2021 9:00 AM EDT, by University of Michigan

Newswise — People who experience very severe COVID-19 illness have a higher prevalence of persistent symptoms, according to a new University of Michigan study.

The findings highlight the urgent need to characterize and treat long-haulers—people who continue to experience lingering symptoms months after their initial diagnosis. Referred to as post-acute sequelae of SARS-CoV-2 infection, or PASC, symptoms include extreme fatigue, shortness of breath and persistent loss of taste or smell.

"While we're in the midst of trying to stop the spread of the pandemic, we need to develop formal, coordinated surveillance of long-term symptoms to better understand this syndrome and provide guidance for clinical management," said lead author Jana Hirschtick, a research investigator in the Center for Social Epidemiology and Population Health at the U-M School of Public Health. 

Hirschtick and colleagues found that 53% of COVID-19 survivors had persistent symptoms 30 days post-COVID onset, while 35% were symptomatic 60 days post-onset. 

For their analysis, the researchers used the Michigan COVID-19 Recovery Surveillance Study, a population-based study of adults 18 and older with a PCR-confirmed SARS-CoV-2 test in the Michigan Disease Surveillance System. All noninstitutionalized adults with a valid phone number and zip code or county in MDSS who were alive at the time the survey sample was drawn were eligible for selection.   

The U-M research team used a random sample of 2,000 adults with COVID-19 onset on or before April 15, 2020, from 13 geographic areas, six counties (Macomb, Oakland, St. Clair, Monroe, Washtenaw, Wayne) and one city (Detroit) in Michigan. Of the sample, 629 completed the survey between June-December 2020. 

The researchers estimated prevalence of persistent symptoms 30 and 60 days after COVID-19 onset, and included sociodemographic and clinical factors as well as self-reported symptom severity and hospitalization status. 

Their final sample with data available for the study (593) was predominantly female (56%), aged 45 and older (68%), and non-Hispanic white (46%) or Black (35%). Of the respondents:

  • 53% reported symptoms at 30 days and 35% reported symptoms at 60 days.
  • Respondents reporting very severe (vs. mild) symptoms had 2.25 times higher prevalence of symptoms at 30 days and 1.71 times higher prevalence of symptoms at 60 days. 
  • Hospitalized (vs. nonhospitalized) respondents had about 40% higher prevalence of symptoms at 30 and 60 days. 
  • Although persistent symptoms were more prevalent among older respondents and those with severe disease, 21% of 18-to-34-year-olds and 25% of respondents reporting mild illness still had symptoms 60 days after their COVID-19 onset.
  • Older age, lower income, self-reported severe or very severe (vs. mild) symptoms and hospitalization statistically significantly predicted 30-day COVID-19, while having a diagnosed psychological disorder, very severe symptoms and hospitalization statistically significantly predicted 60-day COVID-19.

"Our data suggest a significant proportion of people with COVID-19 will continue to experience symptoms, even among people with relatively mild initial illness," said Nancy Fleischer, associate professor of epidemiology and principal investigator of the Michigan COVID-19 Recovery Surveillance Study.

Due to a lack of a clear definition of the illness and of population-based studies, prevalence estimates vary greatly, the researchers say. Their study sought to provide PASC prevalence estimates using a population-based sample of diagnosed COVID-19 cases in Michigan, and assess demographic and clinical correlates of PASC.

After adjusting the models, researchers also found that:

  • There were no statistically significant differences in 30-day or 60-day COVID-19 by race/ethnicity. 
  • Annual household income was a strong and significant predictor of 30-day COVID-19. Even after adjusting for demographic and clinical factors, respondents with an income less than $75,000 had about 40% higher prevalence of 30-day COVID-19 than respondents with an income at or above $75,000.
  • Income was not significantly associated with 60-day COVID-19 in fully adjusted models.
  • Respondents with a psychological condition had 42% higher prevalence of 60-day COVID-19.
  • Self-reported acute illness severity was strongly associated with both 30-day and 60-day COVID-19.

"These results add to the growing body of evidence that a sizable proportion of symptomatic COVID-19 cases of varying severity experience PASC," Fleischer said. "People are continuing to suffer from symptoms well after their initial illness, and the medical and public health communities need to help address this ongoing crisis." 


Among the study limitations, the sample includes individuals with COVID-19 onset in Michigan early in the pandemic, when access to testing was limited, which may limit generalizability of their findings.

The Michigan COVID-19 Recovery Surveillance Study now has data on respondents with COVID-19 onset through September 2020, and will be examining PASC among this larger group of respondents. Additionally, researchers will be examining characteristics and predictors of different subsets of PASC symptoms, which may represent distinct syndromes. 

The study was supported by the Michigan Department of Health and Human Services, Michigan Public Health Institute, U-M Institute for Data Science; U-M Rogel Cancer Center and the Department of Epidemiology at the U-M School of Public Health.

Related stories:


Michiganders with COVID-19 experienced a double whammy of prolonged illness, economic distress


U-M, state of Michigan surveying coronavirus survivors to inform future response to pandemic


Filters close

Showing results

110 of 6084
Newswise: Public
Released: 28-Jul-2021 2:45 PM EDT
Highly Potent, Stable Nanobodies Stop SARS-CoV-2
Max Planck Society (Max-Planck-Gesellschaft)

Göttingen researchers have developed mini-antibodies that efficiently block the coronavirus SARS-CoV-2 and its dangerous new variants.

Newswise: Public
Released: 28-Jul-2021 2:20 PM EDT
Psychological Consequences of COVID-19 in Health Care
University of Bonn

Physicians, nursing staff, medical technical assistants, and pastoral workers in hospitals: they have all been placed under severe strain by the Covid-19 pandemic.

Newswise: Public
Released: 28-Jul-2021 2:10 PM EDT
Why Lockdown in Africa Does Not Work as a First COVID-19 Pandemic Response
University of Johannesburg

In an African pandemic it is more productive to consider lockdowns, after using other non-medical measures first, Especially in countries with high levels of poverty and corruption, says Prof Nicholas Ngepah, a Professor of Economics at the University of Johannesburg in South Africa.

Newswise:Video Embedded how-to-talk-with-people-who-are-not-vaccinated-against-covid-19
Released: 28-Jul-2021 1:40 PM EDT
How to Talk With People Who Are Not Vaccinated Against COVID-19

Even though she has asthma, putting her at higher risk for severe complications from COVID-19, Angela Reeves-Flores, 33, waited until a week ago to get vaccinated.

Newswise: Indian Women’s Nutrition Suffered During COVID-19 Lockdown
Released: 28-Jul-2021 12:50 PM EDT
Indian Women’s Nutrition Suffered During COVID-19 Lockdown
Cornell University

A new study from Cornell University finds the nationwide lockdown India imposed last year in response to COVID-19 caused disruptions that negatively impacted women’s nutrition.

Released: 28-Jul-2021 12:00 PM EDT
MD Anderson Research Highlights for July 28, 2021
University of Texas M. D. Anderson Cancer Center

The University of Texas MD Anderson Cancer Center’s Research Highlights provides a glimpse into recently published studies in basic, translational and clinical cancer research from MD Anderson experts. Current advances include a newly discovered protein that controls B cell survival, understanding epigenetic changes in malignant peripheral nerve sheath tumors (MPNSTs) and melanoma, identifying a protein that protect genome stability, developing novel cell therapies for COVID-19, a new option for treating neuropathic pain, exosome delivery of CRISPR/Cas9 to pancreatic cancer, discovering how cancer cells tolerate aneuploidy and the role of health disparities in long-term survival of adolescent and young adult patients with Hodgkin lymphoma.

Released: 28-Jul-2021 11:30 AM EDT
Study Reveals Characteristics of SARS-CoV-2 Spike Protein
University of Kentucky

A new University of Kentucky College of Medicine study published in the Journal of Biological Chemistry provides foundational information about SARS-CoV-2’s spike protein.

access_time Embargo lifts in 2 days
Embargo will expire: 4-Aug-2021 9:00 AM EDT Released to reporters: 28-Jul-2021 11:15 AM EDT

A reporter's PressPass is required to access this story until the embargo expires on 4-Aug-2021 9:00 AM EDT The Newswise PressPass gives verified journalists access to embargoed stories. Please log in to complete a presspass application. If you have not yet registered, please Register. When you fill out the registration form, please identify yourself as a reporter in order to advance to the presspass application form.

Newswise: UIC Awarded $6 Million to Develop Potential COVID-19 Treatment
Released: 28-Jul-2021 10:15 AM EDT
UIC Awarded $6 Million to Develop Potential COVID-19 Treatment
University of Illinois Chicago

Researchers at the University of Illinois Chicago are developing a potential treatment for COVID-19, thanks to a $6 million technology and therapeutic development award from the U.S. Department of Defense supporting pre-clinical animal studies.

Newswise: Don’t Let the Raging Virus Put Life in Jeopardy. Chula Recommends How to Build an Immunity for Your Heart Against Stress and Depression
Released: 28-Jul-2021 8:55 AM EDT
Don’t Let the Raging Virus Put Life in Jeopardy. Chula Recommends How to Build an Immunity for Your Heart Against Stress and Depression
Chulalongkorn University

Cumulative stress, denial, and chronic depression are the byproducts of the COVID-19 pandemic. The Center for Psychological Wellness, Chulalongkorn University recommends ways to cope by harnessing positive energy from our heart.

Showing results

110 of 6084