CIDRAP Healthcare workers (HCWs) with COVID-19 had more severe symptoms that lasted longer than those with other respiratory diseases, and a higher proportion met the World Health Organization (WHO) or UK National Institute for Health and Care Excellence (NICE) definitions of long COVID, according to a report published in Viruses and Viral Diseases.
A team led by Murdoch Children’s Research Institute investigators in Parkville, Australia, also identified older age, chronic respiratory disease, and pre-existing symptoms as risk factors for long COVID, also known as post-acute COVID-19 syndrome (PACS).
Data from phase 3 clinical trial
The researchers analyzed data on long-COVID symptoms, duration, and pre-existing symptoms from the multinational randomized controlled trial (RCT) BRACE trial on HCWs diagnosed as having COVID-19 or another respiratory illness for 1 year after diagnosis.
Participants were tested for COVID-19 infection if they reported symptoms, gave blood samples every 3 months for evaluation for SARS-CoV-2 antibodies, and completed quarterly surveys. A subsample of 184 COVID-19 and 184 non-COVID controls were also chosen for a case-control analysis of daily symptom data with an extended pre- and post-infection follow-up period.
BRACE is a phase 3 RCT assessing the effect of bacillus Calmette-Guérin (BCG) tuberculosis vaccination on COVID-19 infection in HCWs in Australia, Brazil, the Netherlands, Spain, and the United Kingdom from March 2020 to April 2021.