A study published in Nature Medicine looks at long COVID in a group of 312 patients in Norway.
Dr David Strain, Senior Clinical Lecturer, University of Exeter, said:
“This is a fascinating manuscript that has performed a detailed exploration of long COVID, and gives a particular insight into potential mechanisms. The very detailed follow-up of this population demonstrated rates of on-going symptoms at 6 months much higher than the current ONS estimates in the UK – between 55% for the non-hospitalised patients rising to 81% with the hospitalised population. This is more likely to be due to the difference between a regular prompted review in the current study, compared with the unprompted recall that the ONS is dependent on. There is also no sense of severity of symptoms in this study, which may result in people reporting fatigue when directly questioned, that they would not ordinarily have noticed or commented on in a less directed survey.
“It is concerning that over half of the population from 15-30 years report ongoing symptoms beyond 6 months, given the current rise in cases amongst this age group within the UK. This is a population who, both in this study and in UK practice, are unlikely to have severe initial infections, however the ongoing neurological and physical symptoms described by these young adults, support the government’s decision to slow down the roadmap to recovery until the vaccination program can reach all of these individuals. Whilst the very low percentage in those under 15 should be reassuring for parents looking at the current rise in UK cases in school age children, it should be interpreted with the caution that this is based on very low numbers (only 16 children) and a variant of the virus that did not cause any detectable disease in this population.
“The association between number of symptoms and the antibody response to the virus lends weight to the theories that this has an underlying immune mechanism. This is in keeping with the observations that vaccination is making a significant proportion of individuals with long COVID feel better, and lends hope to all, including those who were not so fortunate, that treatments with immuno-modulants (that affect the immune system)may be on the horizon to help those who are still debilitated by this disease months, indeed over a year later.”
Prof Peter Openshaw, Professor of Experimental Medicine, Imperial College London, said:
“In this nice prospective study of 312 patients (82% of cases in Bergen, Norway) recruited during the first wave. Cases were followed up for 6 months; some were milder (247 home-isolated) and others more severe (65 were hospitalized).
“At 6 months, 61% had persistent symptoms. This was predicted by severity of initial illness, convalescent anti-SARS-CoV-2 antibody titres and pre-existing lung disease.
“Perhaps the most remarkable finding is that in young adults (aged 16–30 years), 52% (32/61) had symptoms at 6 months. These included loss of taste/smell (28%, 17/61), fatigue (21%), dyspnoea (13%), poor concentration (13%) and memory (11%).
“The findings highlight the importance of avoiding infection by control measures that include vaccination in young adults, even if they are only at risk of mild COVID.
“The major caveat is that there was no control group. How many people suffer similarly after other common colds, or flu? How much did the intensive follow up and the high level of interest and anxiety affect the findings?
“The authors point out that in Norway, 11% of general population have chronic fatigue compared to 14% in the present study. As usual, more research is needed.”
Dr Michael Head, Senior Research Fellow in Global Health, University of Southampton, said:
“It is hard to generalise too much on the findings within this paper, given the location of Bergen in Norway and the sample size of 312. However, the research does add to the emerging evidence base that long covid is extremely common across all age groups and not just observed in older individuals or those who were hospitalised. In the UK±, over 1 million people self-report long covid, and around one-third of these reported initial an initial COVID-19 infection over 1 year ago. Fatigue is the most commonly reported symptom.
The researchers also note that the prevalence and severity of COVID-related fatigue appears to be greater than the longer-term fatigue seen in influenza or in glandular fever¥. This does make decision-making around a ‘return to normal’ more complex than just reviewing metrics of hospitalisations numbers or deaths from COVID-19. There must also be due consideration of the ongoing and significant burden of disease from long covid”
± Reference for UK data https://www.ons.gov.uk/peoplepopulationandcommunity/healthandsocialcare/conditionsanddiseases/bulletins/prevalenceofongoingsymptomsfollowingcoronaviruscovid19infectionintheuk/4june2021
¥Glandular fever is caused by the Epstein-Barr virus, as mentioned by the researchers in the press release
Dr Elaine Maxwell, Scientific Advisor National Institute for Health Research (NIHR), said:
“This adds to what we already know, and the age profile has been seen in the ONS data.
“I think it’s pretty well established that Long Covid numbers in non hospitalised patients will exceed those who were hospitalised, due simply to the much greater number of people who have managed their Covid19 infection at home, and the recent papers from UCLH and Defence Medical Rehabilitation centre show that people not admitted to hospital may have a different phenotype.
“Every study uses different inclusion criteria so estimates of prevalence vary according to definition rather than by what is actually happening. This estimate is in the middle of the range we reported in our last review in March.
“So good to see confirmation, but nothing that hasn’t already been reported elsewhere.”
‘Long COVID in a prospective cohort of home-isolated patients’ by Bjørn Blomberg et al. was published in Nature Medicine on Wednesday 23 June
All our previous output on this subject can be seen at this weblink: