Between six and twelve months following coronavirus infection, about a third of persons report at least one persistent symptom, according to a survey of 152,000 adults in Denmark.
The study enrolled the biggest group of persons who were not hospitalised with COVID to date and followed them for a longer period of time than previous large studies, according to the researchers from Denmark’s State Serum Institute (SSI).
According to the questionnaire-based study, the most often reported long-term complaints included changes in smell and taste, as well as weariness.
The poll, which took place between September 2020 and April 2021, far before the recent Omicron variant increase, compared the replies of 61,002 persons who tested positive for coronavirus six, nine, or 12 months before to the survey with those of 91,878 people who tested negative.
Overall, 29.6% of respondents who tested positive reported at least one persistent physical symptom six to twelve months after infection, compared to 13% in the control group.
Within the six to twelve months following infection, slightly more than half (53.1 percent) of people with positive tests reported experiencing mental or physical weariness, sleep issues, or cognitive impairments. This compares to a control group rate of 11.5 percent.
The study also found that persons with a history of SARS-CoV-2 infection were more likely to get new diagnoses of anxiety and despair.
The work was released as an advance online publication and has not yet been peer reviewed.
The findings, according to study author Anders Peter Hviid, an epidemiology professor at SSI, are another indication that policymakers should consider COVID-19’s long tail.
“It’s something you should consider when evaluating the risks and advantages of… the procedures you’re performing and immunizations,” he said in a phone interview, emphasising the need for more research.
Prevalence estimates for what is known as extended COVID vary. The World Health Organization (WHO) refers to this disorder as Post-COVID-19 syndrome. It is defined as persistent symptoms – such as fatigue or shortness of breath – three months after the first infection that remain for at least two months.
The WHO believes that between 10% and 20% of persons are impacted at that stage and notes that further research is needed to determine the longer-term prognosis.
According to David Strain, a lecturer at the University of Exeter Medical School in the United Kingdom who was not involved in the study, the finding is “very alarming.”
“If Omicron continues to cause extended Covid at the same rate as these previous forms, we might be in for a significant issue within the next 12 months, considering the amount of people exposed to this virus,” he warned.