Young and healthy adults that tested positive for COVID-19 can take weeks to fully recover from even a mild infection, according to a new CDC report.

This shows that the recuperation from the novel coronavirus can be a long and tedious process for many patients from different age groups.

The Centers for Disease Control and Prevention (CDC) carried out a telephone survey across 13 states, interviewing 274 symptomatic adults with mild COVID-19. Out of them, 35% reported not returning to their usual state of health two to three weeks after testing positive.

“COVID-19 can result in prolonged illness even among persons with milder outpatient illness, including young adults,” the report’s authors wrote. It’s the first acknowledgment of its kind from the CDC, suggesting that prolonged symptoms from the novel coronavirus aren’t limited to severe cases.

The survey was carried out 14 to 21 days after the test, asking patients about symptoms during testing, whether they had returned to their usual state of health, and if they suffer from a chronic medical condition. Among those who had prolonged symptoms, 26% were between 18 and 41 years old, 32% between 35 and 49, and 47% over 50.

Not returning to usual health within 2–3 weeks of testing was reported by approximately 33% of respondents. Even among young adults aged 18–34 years with no chronic medical conditions, nearly one in five reported that they had not returned to their usual state of health 14–21 days after testing

The CDC had argued in the past that “prolonged symptom duration and disability are common in adults hospitalized with severe coronavirus”. This survey further highlights that risk — even young and generally healthy patients with mild cases were still reporting lingering coronavirus symptoms such as cough, fatigue, or shortness of breath weeks after testing positive for the virus.

“Characterizing return to baseline health among outpatients with milder COVID-19 illness is important for understanding the full spectrum of COVID-19–associated illness and tailoring public health messaging, interventions, and policy,” the CDC wrote, highlighting the importance of the findings.

The researchers argued public health messaging should target populations that might not perceive COVID-19 illness as being severe or prolonged — especially young adults and those without chronic underlying medical conditions, who might feel they are completely safe. They called for prevention measures, including social distancing, frequent handwashing, and the use of face coverings.

The findings didn’t come as a surprise for the so-called COVID “long-haulers,” people who say they have been suffering from symptoms of the disease for weeks.

Groups on social media have become viral in recent months, such as “Survivor Corps”, an open group on Facebook with over 83,000 members.