The findings come from a large Dutch study and demonstrate the symptoms of the virus months after people's acute infections.
A new study from the Netherlands shows the lingering effects of COVID-19. According to a large Dutch study published in The Lancet, 1 in 8 adults who are infected with virus feel long term symptoms.
The study comes from data gathered within Lifelines, a multidisciplinary, prospective, population-based, observational cohort study examining the health and health-related behaviors of people living in the north portion of the Netherlands.
The participants were 18 years of age or older. They were sent invitations to digital COVID-19 questionnaires, used longitudinal dynamics of 23 somatic symptoms surrounding COVID-19 diagnoses (due to SARS-CoV-2 alpha [B.1.1.7] variant or previous variants) were assessed using 24 repeated measurements between March 31, 2020, and Aug 2, 2021.
“There is urgent need for data informing the scale and scope of the long-term symptoms experienced by some patients after COVID-19 illness,” Professor Judith Rosmalen from the University of Groningen, lead author of the study, said. “However, most previous research into long COVID has not looked at the frequency of these symptoms in people who haven’t been diagnosed with COVID-19 or looked at individual patients’ symptoms before the diagnosis of COVID-19.”
Even after the acute virus has dissipated, some patients still feel the lingering effects of COVID-19 several months after first becoming infected. In fact, the investigators discovered that several symptoms were new or more severe 3 to 5 months after having COVID-19, compared to symptoms before a COVID-19 diagnosis and to the control group, suggesting these symptoms can be viewed as the core symptoms of long COVID.
Core symptoms recorded were chest pain, difficulties breathing, pain when breathing, painful muscles, loss of taste and/or smell, tingling hands/feet, a lump in throat, alternately feeling hot and cold, heavy arms and/or legs and general tiredness. The severity of these symptoms plateaued at 3 months after infection with no further decline. Other symptoms that did not significantly increased 3 to 5 months after a COVID-19 diagnosis included headache, itchy eyes, dizziness, back pain and nausea.
Of the study participants who had submitted pre-COVID symptom data, the investigators found that 21.4% (381/1,782) of COVID-19-positive participants, compared to 8.7% (361/4,130) of the control group, experienced at least one increased core symptom at moderate severity 3 months or more after SARs-CoV-2 infection. This implies that in 12.7% of COVID-19 patients their new or severely increased symptoms three months post-COVID can be attributed to SARS-CoV-2 infection.
“By looking at symptoms in an uninfected control group and in individuals both before and after SARS-CoV-2 infection, we were able to account for symptoms which may have been a result of non-infectious disease health aspects of the pandemic, such as stress caused by restrictions and uncertainty,” Aranka Ballering PhD candidate and first author of the study, said.
Some of the limitations of the study included patients infected with the Alpha variant or earlier variants of SARS-CoV-2 and has no data from people infected during the period when the Delta or Omicron variants were causing most infections. Additionally, due to asymptomatic infection, the prevalence of COVID-19 in this study may be underestimated.
Another limitation to this study is that since the beginning of data collection other symptoms, such as brain-fog, have been identified as potentially relevant for a definition of long COVID but this study did not look at these symptoms. Furthermore, the study was undertaken in one region and did not include and ethnically diverse population.