LONDON, Aug 5 One in eight adults infected with SARS-CoV-2 will experience long-term symptoms as a result of COVID-19, according to one of the most comprehensive studies of the viral disease to date, published in the journal The Lancet on Friday.
The study provides one of the first comparisons of long-lasting symptoms after SARS-CoV-2 infection, dubbed ‘long COVID’, with symptoms in an uninfected population, as well as those in individuals both pre- and post-COVID-19 infection. .
The inclusion of uninfected populations allows a more accurate prediction of the long-term prevalence of COVID-19 symptoms and a better identification of the core symptoms of long-term COVID.
“There is an urgent need for data that informs the magnitude and scope of the long-lasting symptoms experienced by some patients after COVID-19 disease.” said Professor Judith Rosmalen of the University of Groningen in the Netherlands.
“However, most previous research on long-term COVID-19 has not looked at the frequency of these symptoms in people who have not been diagnosed with COVID-19, nor at the symptoms of individual patients before the diagnosis of COVID-19,” says Rosmalen, lead author of the study.
The study looked at the symptoms most commonly associated with long-term COVID, including difficulty breathing, fatigue, and loss of taste and smell, both before a COVID-19 diagnosis and in people who have not been diagnosed with the disease.
The researchers collected data by asking participants to fill out regular digital questionnaires about 23 symptoms commonly associated with long-term COVID.
The questionnaire was sent to the same individuals 24 times between March 2020 and August 2021, meaning participants who had COVID-19 during that time were infected with the SARS-CoV-2 Alpha variant or earlier variants.
Most of the data was collected before the introduction of the COVID-19 vaccine in the Netherlands, so the number of vaccinated participants was too small to analyze.
Of the 76,422 participants, 4,231 participants with COVID-19 were matched with 8,462 controls, taking into account gender, age and time of completing questionnaires indicating a COVID-19 diagnosis.
The researchers found that several symptoms were new or more severe three to five months after getting COVID-19, compared with symptoms before a diagnosis and with the control group, suggesting that these symptoms could be considered the core symptoms of long-term COVID-19.
The main symptoms recorded were chest pain, difficulty breathing, pain when breathing, aching muscles, loss of taste or smell, tingling hands and feet, a lump in the throat, alternating hot and cold feeling, heavy arms or legs and general fatigue.
The severity of these symptoms stabilized three months after infection with no further decrease, the researchers said.
Other symptoms that didn’t increase significantly three to five months after a COVID-19 diagnosis included headaches, itchy eyes, dizziness, back pain and nausea, they said.
“These core symptoms have major implications for future research, as these symptoms can be used to differentiate between post-COVID-19 condition and non-COVID-19-related symptoms,” said PhD student Aranka Ballering, lead author of the study.
Of the study participants who submitted pre-COVID symptom data, the researchers found that 21.4 percent of the COVID-19-positive participants, compared with 8.7 percent of the control group, experienced at least one elevated core symptom at moderate severity at 3 months. or more after SARS-CoV-2 infection.
This means that in 12.7 percent of COVID-19 patients, their new or severely increased symptoms three months after COVID can be attributed to a SARS-CoV-2 infection.
“This is a major advance over previous long estimates of COVID prevalence as it includes a matched uninfected group and explains symptoms before COVID-19 infection,” said Professor Christopher Brightling and Rachael Evans of the University of Leicester , UK.
“The pattern of symptomatology observed by Ballering and colleagues was similar to previous reports with fatigue and shortness of breath as the most common symptoms, but interestingly, other symptoms such as chest pain were more of a feature in people with long-term COVID versus uninfected controls.” The scientists, who were not involved in the study, noted.
The authors acknowledge some limitations in the study, as it included patients infected with the Alpha variant or previous variants of SARS-CoV-2 and there is no data from people infected during the period when the Delta or Omicron virus was present. variants caused the most infections.
Due to an asymptomatic infection, the prevalence of COVID-19 in this study may also be underestimated, the researchers said.
Another limitation of the study is that since the start of the data collection, other symptoms, such as brain fog, have been identified as potentially relevant to a definition of long-term COVID, but this study did not look at these symptoms, she added. (PTI)