1 in 10 people still experience symptoms of COVID-19 8 months after infection, according to a new study by researchers at Danderyd Hospital and Karolinska Institutet in Sweden
Researchers have discovered that 1 in 10 people still experience at least one moderate to severe long-term symptom of COVID-19 8 months after mild infection. The study, published in the journal JAMA, also found that the most common long-term symptoms are a loss of smell, taste and fatigue.
In the first phase, blood samples were collected from 2,149 employees at Danderyd Hospital and have since then been collected every four months. The study participants, of whom about 19% had antibodies against SARS-CoV-2, also responded to questionnaires regarding long-term symptoms and their impact on the quality of life.
In the third follow-up, the research team examined self-reported presence of long-term symptoms and their impact on work, social and home life for participants who had had mild COVID-19 at least eight months earlier.
This group consisted of 323 healthcare workers (83% women, median age 43 years) and was compared with 1,072 healthcare workers (86% women, median age 47 years) who did not have COVID-19 throughout the study period.
The results presented that 26% of those who had COVID-19 previously, compared to 9% in the control group, had at least one moderate to severe symptom that lasted more than two months and that 11%, compared to 2% in the control group, had a minimum of one symptom with negative impact on work, social or home life that lasted at least eight months.
Charlotte Thålin, specialist physician, Ph.D. and lead researcher for the COMMUNITY study at Danderyd Hospital and Karolinska Institutet, said: “We investigated the presence of long-term symptoms after mild COVID-19 in a relatively young and healthy group of working individuals, and we found that the predominant long-term symptoms are loss of smell and taste. Fatigue and respiratory problems are also more common among participants who have had COVID-19 but do not occur to the same extent.
“However, we do not see an increased prevalence of cognitive symptoms such as brain fatigue, memory and concentration problems or physical disorders such as muscle and joint pain, heart palpitations or long-term fever.”
“Despite the fact that the study participants had a mild COVID-19 infection, a relatively large proportion report long-term symptoms with an impact on quality of life. In light of this, we believe that young and healthy individuals, as well as other groups in society, should have great respect for the virus that seems to be able to significantly impair quality of life, even for a long time after the infection,” added Sebastian Havervall, deputy chief physician at Danderyd Hospital and PhD student in the project at Karolinska Institutet.
“We will, among other things, be studying COVID-19-associated loss of smell and taste more closely, and investigate whether the immune system, including autoimmunity, plays a role in post-COVID,” Charlotte Thålin concluded.