The most common persistent symptoms in recovered COVID-19 patients were fatigue and loss of sense of smell or taste, according to a new study. Researchers at the University of Washington, Seattle, surveyed a couple hundred patients three to nine months after they were confirmed to have the infection, as well as a set of uninfected controls.

Long COVID, has become a syndrome on its own, as many people who are infected by this virus go on to experience long term side effects: these include fatigue, headaches, brain fog, memory loss, gastrointestinal problems, muscle aches and heart palpitations. Some patients have even developed diabetes.

As the authors of this most recent study write “Notably, 14 participants, including nine non-hospitalized individuals, reported negative impacts on daily living activities after infection. With 57.8 million cases worldwide, even a small incidence of long-term debility could have enormous health and economic consequences.” They believe their study is the largest to date looking at long term health effects of this infection.

In this study, only about 6% of the COVID-19 patients stayed asymptomatic. Almost 85% had moderate symptoms, but remained outpatients, and 9% had moderate or severe disease that led to re-admission to a hospital.

The lead author of this study is Jennifer K. Logue. It was published in JAMA Network Open last week.

A total of 177 of 234 participants with COVID-19 completed the survey, which was received between 31-300 days after COVID-19 onset, with a median of 169 days.

Among participants with COVID-19, persistent symptoms were reported by 17 of 64 patients (26.6%) aged 18 to 39 years, 25 of 83 patients (30.1%) aged 40 to 64 years, and 13 of 30 patients (43.3%) aged 65 years and older. Overall, 49 of 150 outpatients (32.7%), 5 of 16 hospitalized patients (31.3%), reported at least 1 persistent symptom. Of 31 patients with hypertension or diabetes, 11 (35.5%) experienced ongoing symptoms.

The most common persistent symptoms were fatigue (24 of 177 patients [13.6%]) and loss of sense of smell or taste (24 patients [13.6%]). Overall, 23 patients (13.0%) reported other symptoms, including brain fog (4 [2.3%]). A total of 51 outpatients and hospitalized patients (30.7%) reported worse health-related quality of life (HRQoL) compared with baseline vs 4 healthy participants and asymptomatic patients (12.5%); 14 patients (7.9%) reported negative impacts on at least 1 activity of daily living, the most common being household chores.