6 in 10 people continue to suffer a year after COVID infection: Study

Six in ten people with COVID-19 still have at least one symptom a year later, a new study being presented at this year’s European Congress of Clinical Microbiology & Infectious Diseases (ECCMID) in Lisbon, Portugal has found.

The researchers in Luxembourg found that COVID-19 symptoms that don’t clear up after 15 weeks are likely to last at least a year. An estimated 25-40% of people with COVID-19 develop long COVID – persisting symptoms that can affect multiple organs and include mental health problems. Most of the data to date, however, is based on patients who were hospitalised with COVID-19 and it isn’t clear how it applies to COVID-19 cases more generally.

To find out more, Aurelie Fischer and colleagues at the Luxembourg Institute of Health, Strassen, Luxembourg, surveyed almost 300 people a year after they were diagnosed with COVID-19. The 289 participants (50.2% women) had an average age of 40.2 years and were divided in three groups, based on the severity of their initial infection: asymptomatic, mild and moderate/severe COVID-19.

They were asked to fill in a detailed questionnaire about whether they were experiencing 64 common long COVID-related symptoms. They also filled a questionnaire on sleep quality and one that looked at the effect of respiratory symptoms, such as breathlessness, on quality of life. Six in ten (59.5%) participants had at least one long COVID symptom a year after their initial infection, with fatigue, shortness of breath and irritability the most common.

A third (34.3%) were experiencing fatigue a year on, 12.9% said respiratory symptoms were affecting their quality of life and more than half (54.2%) had ongoing sleep problems. Participants who’d had moderate/severe COVID-19 were twice as likely to still have at least one symptom a year on than those whose initial infection was asymptomatic.

“Participants with a mild form of the acute illness were more likely than those who’d been asymptomatic to have at least one symptom at one year, and to have sleep problems, but to a lesser extent than those with a moderate or severe acute illness.” One in seven participants (14.2%) said they could not envisage coping with their symptoms long-term.

The participants’ health had been tracked since their COVID diagnosis, as part of Predi-COVID, a large-scale study into risk factors and biomarkers associated with COVID-19 severity and long-term health consequences of the disease in Luxembourg. Data from Predi-COVID also revealed that COVID-19 symptoms that didn’t resolve after 15 weeks were likely still to be present a year after initial infection.

“It shows that long COVID can still have a large impact on quality of life, even a year after the acute infection. In general, the more severe the acute illness is, the more likely someone is to have ongoing symptoms; however, those with an asymptomatic or mild initial infection may also experience a deterioration in their quality of life.