A German study published today in BMJ finds a considerable burden of long-COVID symptoms, especially fatigue and neurocognitive impairment ("brain fog"), at 6 to 12 months—even among young and middle-aged adults who had mild infections.

A team led by Ulm University researchers parsed responses to a mailed survey from 11,710 adults aged 18 to 65 years living in southwestern Germany who tested positive for COVID-19 from Oct 1, 2020, to Apr 1, 2021, a period dominated by the wild-type virus.

Average participant age was 44.1 years, 58.8% were women, 56.8% were employed full-time before the pandemic, 77.5% didn't require medical care for their infection, 19.0% needed outpatient care, and less than 4% were hospitalized. Pre-existing chronic conditions included musculoskeletal disorders (28.9%), cardiovascular disease (17.4%), neurologic and sensory disorders (16.2%), and respiratory illnesses (12.1%).

The survey was fielded in August and September 2021, and the average interval between the initial positive COVID-19 test and survey completion was 8.5 months.