One in eight people infected with the coronavirus develops at least one long-term symptom of Covid-19, revealed on Thursday (4) one of the largest studies ever done on the disease.
With more than 500 million cases of coronavirus reported worldwide since the start of the pandemic, concerns have arisen about lasting symptoms in people with long-term Covid.
But few studies have compared people with prolonged Covid to those who haven’t been infected.
A new study published by The Lancet asked more than 76,400 adults in the Netherlands to fill out an online questionnaire on 23 typical symptoms of prolonged Covid.
Between March 2020 and August 2021, each participant answered the questionnaire 24 times.
In that period, more than 4,200, or 5.5%, reported being infected by Covid-19.
Of those, more than 21% had at least one or several severely increased symptoms three to five months after infection.
However, nearly 9% of people in a control group who did not contract Covid-19 reported a similar increase.
This suggests that 12.7% of those who had Covid, nearly one in eight, suffered from long-term symptoms, according to the study.
The researchers also recorded symptoms before and after the Covid infection, allowing for the exact identification of what was related to the virus.
They determined that common symptoms of prolonged Covid include chest pain, breathing difficulties, muscle aches, loss of taste and smell, and fatigue.
One of the study’s authors, Aranka Ballering, from the University of Groningen in the Netherlands, said that prolonged Covid was “an urgent problem, with an increasing human cost”.
“By looking at symptoms in an uninfected control group and in individuals before and after a Sars-CoV-2 infection, we were able to see symptoms that could be a result of non-infectious health aspects of the pandemic, such as stress caused by restrictions and uncertainties,” he added.
The authors acknowledged that the study has limitations in that it does not cover late variants such as Delta or Ômicron and does not collect information on symptoms such as lapses in the mind, considered typical of prolonged Covid.
Christopher Brightling and Rachael Evans, experts at the University of Leicester in the UK who were not involved in the study, said it was “a big improvement” over previous studies because it included a control group of uninfected people.