Long COVID Persists 2 Years After Infection: Saint Joseph's Health Research

PASSAIC COUNTY, NJ — COVID-19's severity often gets characterized in terms of cases, hospitalizations and deaths. But another serious issue persists: long COVID, and it can last for two years after infection with the virus, according to research from the Saint Joseph's Health Network.

Formally called post-acute COVID-19 syndrome (PACS), long COVID is characterized by the persistence of symptoms at least four weeks after initial infection with the virus. Long COVID can occur even in mild cases. While the research points to several studies saying it lasts up to a year, research from St. Joseph's found its prevalence two years post-infection.

"To our knowledge this is the first US study to describe the duration and symptomatology of COVID-19 in patients over a two year follow up period," the authors wrote.

The study — published in peer-reviewed journal Clinical Microbiology and Infection — included 173 people diagnosed with COVID in March or April 2020 in the Passaic County-based health network. Ninety-one were hospitalized with the virus, while 82 got diagnosed in an outpatient setting.

During follow-ups after one year, 50.8 percent of the patients still had at least one persistent symptom. The most common were shortness of breath (25 percent), fatigue (24 percent) anxiety (21 percent), difficulty focusing/brain fog (18 percent), body aches (18 percent) and headaches (16 percent).

After two years, 21.3 percent of patients still had at least one persistent symptom — the most common being shortness of breath (13.2 percent), fatigue (12.1 percent), difficulty focusing/brain fog (10.4 percent), memory loss (9.2 percent) and anxiety (8.1 percent).

The study didn't include minors or people with cognitive impairment. But several studies warn that long COVID isn't uncommon in children.

Outside of independent research, there's little publicly available data on long COVID, making it challenging for the public to gage its severity and prevalence. The CDC says studies are in progress to better understand PACS.

But there may be 4 million full-time equivalent workers out of jobs because of long COVID, according to Brookings Institution estimates.

"That is just a shocking number," Katie Bach, a Brookings Institution senior fellow, told NPR. "That's 2.4% of the U.S. working population."

Researchers acknowledged their study's small sample size. But they warned that PACS remains poorly defined and needs more extensive research.

"With over half a billion people infected worldwide, thousands of new infections daily, and weaning protection from immunization or prior infection, a global public health crisis could be looming," researchers wrote. "For millions of patients, PACS can significantly impair cognitive function, quality of life and the ability to work at full capacity for years to come."

Read more about the research here.