The Office for National Statistics (ONS) have released the latest estimates of the prevalence of self-reported ‘long COVID’ and associated activity limitation, using data from the UK COVID-19 Infection Survey.
Dr David Strain, Clinical Senior Lecturer and Honorary Consultant, University of Exeter Medical School, said:
“The increase in number of cases of long Covid is not at all surprising given the recent UK strategy of managing Covid based on the risk of hospitalisation and death alone. We have seen cases of long Covid due to the omicron BA.2 variant be at least as high as previous variants, despite not causing the same hospitalisation rate. The most concerning figure here however is the 376,000 people who have had the disease for over two years, remembering this by definition is only looking at the first four months of Covid infections in the UK. This number will inevitably climb as all of those who caught Covid in the second, third and fourth waves experience continued symptoms.
“It is important to caveat that these are self-reported figures. There are many people who have experienced Covid and are still feeling “not quite right” who probably would not identify as having long Covid. This is particularly true in some ethnicities who have different perceptions of health and disease, and may account for why people of colour appear to be under-represented in these numbers. As such the legacy of this pandemic may be much bigger. Prospective studies in China, Denmark, and Norway have all demonstrated the percentage of people who experience any residual symptoms (irrespective of how minor) to be significantly higher than our figures, ranging from 23% of those who contract COVID in the community and up to 76% of those who were hospitalised due to Covid. These numbers were pre-vaccination, and include any symptom reported by the patient on direct questioning, which may not always be attributable to the COVID itself. The ONS has already demonstrated that the likelihood of developing long COVID in a fully vaccinated population are reduced by about 40% compared to an unvaccinated population. They also provide one of the best national pictures of people continuing to independently report symptoms in the world . By inclusion of only those who are self-reporting symptoms, thereby excluding all of the minor symptoms that have a minimal impact on individuals’ quality of life, this report may better reflect the wider impact of long Covid on society and healthcare needs.
“There are currently several different theories as to the underlying cause of the symptoms. These range from residual virus “hiding” in tissues that the immune system cannot easily get to, such as the brain or the gut. This then causes a slow release of chronic inflammation making people feel constantly debilitated. Other theories include an autoimmune reaction, where the body continues to fight itself once it is done fighting the virus; permanent damage done to the mitochondria (The powerhouse off each individual cell), or changes in our immune responsiveness to every day environmental bacteria and viruses.
“There is much yet to learn about this disease, in no small part because previous research into post viral fatigue syndromes, such as myalgic encephalomyelitis (ME, sometimes known as chronic fatigue syndrome) is far from complete, indeed in some settings woefully inadequate.
“There are studies underway to identify the cause including looking into the genetics of the disease [I am the chief investigator of this one], as well as studies looking at potential treatment of both symptoms and cures – for example the LOCOMOTION or STIMULATE ICP study.”
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