LONG Covid appears to be more prevalent in women and young people (including children) than might have been expected from acute Covid-19 mortality, according research cited by the National Institute for Health Research Centre for Engagement and Dissemination (NIHR) in a second "themed review" on the condition.
The review also found that among Covid-19 patients admitted to hospital, between 50-89 per cent had at least one enduring symptom after two months. Among those not admitted to hospital, 20-30 per cent experience at least one enduring symptom around one month later and at least 10 per cent three months later.
The review also cites considerable variation in the range of symptoms that have been labelled as ‘Long Covid’ by researchers and that it may refer to up to four syndromes, with different underlying causes and treatment needs.
The first themed review by NIHR was published in October 2020 and this follow-up considered over 300 papers and academic opinion pieces from across the world, providing a "unique", evidence-based perspective.
Among other findings it cites increased evidence of organ impairment in both people who were admitted to hospital and those who stayed at home. One study also considered in the review reported that 30 per cent of Covid-19 patients suffered from anxiety and/or depression between 1-3 months after clearance of the virus. There is also some indication that ‘brain fog’ - one of the recurring pattern of symptoms relating to Long Covid - has a neurological rather than a social cause.
Professor Chris Whitty, Chief Medical Officer and co-lead for the National Institute for Health Research, commented: "This is a useful review of evidence currently available on the prolonged post-Covid symptoms currently termed ‘Long Covid’ which is highly debilitating for some of those who have had Covid.
"What we currently term ‘Long Covid’ likely covers a range of syndromes, which will require different approaches. It is important that we work out what exactly the various elements of ‘Long Covid’ are and then we can target research at these parts in order to prevent and treat it."
Dr. Elaine Maxwell, review author and Content Lead at the NIHR Centre for Engagement and Dissemination said: "While this review goes some way to improving our understanding of different patterns of the disease, we need to know more about the prevalence of each and their causes. We also need more data on how long symptoms last.
"It appears that at least 10 per cent of people are experiencing at least one Long Covid symptom three months after diagnosis, but limitations in the way data is collected means this may not be a comprehensive reflection and we may see estimates increase."