Two-Thirds of Mild COVID Cases Leave Long-Term Symptoms

A little more than two out of every three people who have mild or moderate cases of COVID-19 will go on to develop long-term symptoms.

That's the troubling takeaway from a University of Arizona Health Sciences' study launched in May 2020.

"This is a real wake-up call for anyone who has not been vaccinated," said lead researcher Melanie Bell, a professor of biostatistics in the university's College of Public Health. "If you get COVID, the chances that you'll experience long-term symptoms are surprisingly high."

The CoVHORT study has followed Arizonans who had COVID-19 since May 2020, as well as those who have not been infected.

Among participants who tested positive for COVID-19, nearly 69% still had least one symptom after 30 days, and the rate rose to 77% after 60 days.

Those with long COVID tended to be less educated, to have seasonal allergies and pre-existing health conditions, and to self-report greater symptom severity, according to findings published online Aug. 4 in the journal PLOS ONE.

Thirty days after their positive test, the most common symptoms among patients with long COVID were fatigue, shortness of breath, brain fog, stress/anxiety, altered taste and smell, body aches and muscle pain, insomnia, headaches, joint pain and congestion.

The median number of symptoms was three, but some patients had as many as 20. (Median means half had fewer symptoms, half had more.)

The rate of long COVID among the patients in this study was just slightly less than that estimated for hospitalized COVID-19 patients, the authors noted.

Much of the research on long COVID has focused on hospitalized patients with severe infection. The CoVHORT study aims to fill in gaps by focusing on non-hospitalized COVID-19 patients.

The researchers said their study continues to provide important data that can help identify which COVID-19 patients are most susceptible to severe infection and long-term health consequences.

"I study reproductive health," said Leslie Farland, an assistant professor of public health. "And the data from the CoVHORT longitudinal study is already providing new insights," she explained in a university news release.