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Take a look at a selection of our recent media coverage:
6th November 2023
Tens of thousands of people are suffering with long Covid symptoms more than a year after infection, say researchers who carried out the UKs largest study of the impact of the virus.
A survey of a quarter of a million people taking part in the REACT study found that while most people recover within 12 weeks, 7.5% of people had persistent symptoms for more three months and 5% reported symptoms lasting more than a year.
But people infected in the Omicron wave of the pandemic were 88% less likely to experience symptoms longer than four weeks after infection, compared to earlier wave, the study found, which could be due to immunity building up in the population and vaccination.
The new analysis, published in the journal Nature Communications, also highlighted how persistent symptoms of Covid-19 were related to worse mental health and quality of life.
Being female, already having more than one comorbidity, being from a deprived area, and being infected with an original strain of Covid-19 were all related with higher risk of symptoms lasting more than 12 weeks and longer recovery time in those with persistent symptoms, the researchers said.
The survey results – which were collected in towards the end of 2022 – show a snapshot of the continued impact of Covid-19 in the UK, the Imperial College London team noted.
Mild fatigue, difficulty thinking or concentrating and joint pains were the most common ongoing symptoms. But others reported loss or change of sense of smell or taste, shortness of breath, severe fatigue, chest tightness or pain, and poor memory.
Almost a third of people reporting symptoms at 12 weeks recovered within a year, the researchers found.
Professor Paul Elliott, chair of epidemiology and public health medicine at Imperial College London, said: ‘We find that the variant of SARS-CoV-2 people are infected with, the initial severity of their symptoms, and whether they have pre-existing health conditions all have an impact on whether they will develop lasting symptoms.’
Study lead Dr Christina Atchison, principal clinical academic fellow within the School of Public Health at Imperial College London, said while the landscape has changed considerably since the early peak of the Covid-19 pandemic, this analysis shows that a proportion of adults are still experiencing lasting symptoms.
‘Importantly, we find that compared to wild type virus, those infected when Omicron was dominant were far less likely to report symptoms lasting beyond 12 weeks,‘ she said. ‘This may reflect the changing levels of immunity in the population from previous exposure to the virus and vaccination.’
The team is now doing detailed interviews with some of those affected with ongoing symptoms to further understand the variation in people’s experiences and the impact on their everyday lives as well as the broader longer-term impact of the pandemic on health and wellbeing of those who took part in REACT.
11th May 2023
Fergus Gleeson has long held an interest in MRI scanning techniques that use hyperpolarised xenon – an odourless gas – to detect early-stage lung disease. Here, he discusses his interest in xenon, how the gas works in practice and his latest research findings in relation to long-Covid.
In 2020, Fergus Gleeson, professor of radiology at Oxford University and consultant radiologist at Oxford University Hospitals NHS Foundation Trust, turned his attention to a small study of post-Covid patients. They were experiencing breathlessness several months after being discharged from hospital, despite CT scans that appeared to show their lungs were normal.
The findings from this small study prompted Professor Gleeson to widen the research to investigate possible lung damage in non-hospitalised, post-Covid patients who continue to experience breathlessness many months after infection.
He is the principal investigator of the EXPLAIN study, one of 19 projects to receive nearly £40m from the National Institute for Health Research to improve understanding of long-Covid, from diagnosis and treatment through to rehabilitation and recovery.
I’ve worked in the xenon field since 2007/08 to identify patients with obstructive lung disease and interstitial lung disease, as have other researchers, including Professor Jim Wild, who is the head of imaging and NIHR research professor of magnetic resonance at the University of Sheffield. [Indeed, Wild pioneered the method, development and applications of hyperpolarised xenon MRI used in the EXPLAIN study.]
Xenon is unique in its ability to measure gas transfer in the lungs. The MRI scanner is programmed to detect signal from polarised xenon. The oxygen in the normal air we breathe isn’t used because it does not give enough MRI signal. Xenon behaves just like oxygen, so radiologists can use it to observe how it moves from the lungs into the blood stream and highlight any areas where it is not flowing well between the airways, gas exchange membranes and capillaries in the lungs.
The patient lies in an MRI scanner on a magnet with a vest like coil around their chest and breathes in one litre of inert gas xenon through a plastic straw. It is possible to watch the physiology of a patient’s lungs in real time and see where the xenon might be held up, how fast it moves, whether it gets to the alveoli and from this assess how well the exchange of oxygen and carbon dioxide happens in the blood. The degree of gas exchange is colour coded with areas of more damaged lungs being darker or a different colour to areas with normal exchange.
The scan times may be very short, for example a single sequence may only require the patient to breathe in and hold their breath for 14-20 seconds. There’s no radiation exposure so it can be repeated over time to see whether the changes to the lungs improve. If the research proves to be clinically useful, the equipment could be set up in multiple regional centres in a relatively short space of time. All that is needed is a cylinder of xenon and the polariser – which is about the size of a large chest of drawers. The MRI scanner would also need to be modified to detect the signal from the xenon gas.
Ours is located in the radiology department at the Churchill Hospital in Oxford. There’s one in Sheffield University’s imaging department, one is being installed at University College Hospital London and one at Manchester University. There’s also a couple in Denmark, two in Germany, several in the United States and at least one in Canada.
Some people were complaining of persistent breathlessness and fatigue for many months after the Covid-19 infection, so we conducted a small study on patients aged between 19 and 69. None of them required intensive care or ventilation, and standard CT scans showed no significant lung damage. The hyperpolarised xenon MRI scans revealed signs of lung damage for a number of the patients who were reporting breathlessness.
We then broadened the study out to include non-hospitalised individuals who had tested positive for Covid-19 across a range of age groups. Now, there are many different arms of the study and we’re working with three other hospital sites: Sheffield, Manchester and Cardiff. Hundreds of thousands of people in the UK continue to experience symptoms months after having Covid-19, with breathlessness one of the most commonly reported symptoms.
We hope to identify what’s causing patients with long-Covid breathlessness and essentially give them answers as to how long they might have these abnormalities and whether they’ll get better.
We’re using hyperpolarised xenon MRI scans to investigate possible lung damage in long-Covid patients who have not been hospitalised with Covid-19 but who continue to experience breathlessness. The full study will recruit around 400 participants following on from our two initial pilot studies. The EXPLAIN study will include:
We detected significantly impaired gas transfer from the lungs to the bloodstream in long-Covid patients when other tests were normal. These patients had never been in hospital, did not have an acute severe illness when they had their Covid-19 infection, and some had experienced symptoms for a year after contracting it. The important questions that now need answering are how many patients with long-Covid will have abnormal scans, what the significance of the abnormality we’ve detected is, what the cause of the abnormality is and what its longer-term consequences will be. Once we understand the mechanisms driving these symptoms, we will be better placed to develop more effective treatments.
We need to complete recruitment and analyse the data, so we have some way to go before fully understanding the nature of the lung impairment that follows Covid-19 infection. However, the clinical-academic collaboration in EXPLAIN and other studies funded by NIHR are fundamental steps towards understanding the biological basis of long-Covid. This, in turn, will help us to develop more effective therapies.
9th January 2023
An analysis by US researchers suggests that only some of the post COVID-19 condition symptoms can be uniquely attributed to infection with the virus when compared to the post-infection symptoms induced by other, common viral infections.
Post COVID-19 condition which is also commonly referred to as long COVID, is defined as the continuation or development of new symptoms 3 months after the initial COVID-19 infection, with these symptoms lasting for at least 2 months with no other explanation. Although there are a number of specific symptoms that have been recognised, the more common ones have included fatigue, cough, chest tightness, breathlessness, palpitations and myalgia. Nevertheless, it is also known that other viral infections can result in lasting symptoms and myalgic encephalomyelitis or post-viral fatigue syndrome is a common disorder, in which patient complain of exhaustion, fatigue, muscle aches and pains, and invariable psychiatric symptoms such as emotional lability, poor memory/concentration, and depression. Thus it is necessary to have a better understanding of the risks associated with the development of specific symptoms to enable a more accurate characterisation of post COVID-19 condition.
In the present study, the US researchers focused on the identification of the persistent symptoms that could be used to define post COVID-19 condition. They made use of information held in the Cerner Real-World Data, which is large US database that receives input from 122 centres across the US. The researchers looked at a wide range of symptoms and which developed 30 days after an acute infection with either COVID-19 and the common cold, influenza and viral pneumonia. These latter three infections were combined to create a viral respiratory infection (VRI) group and de-identified participants were included if they had at least 365 days of data following their acute infection. In addition, a third cohort which included individuals who did not have any recorded infection with COVID-19 or a VRI were included as controls. Comparisons were then made for COVID-19 vs VRI, COVID-19 vs non-infected controls and VRI vs non-infected controls.
Post COVID-19 condition and subsequent significant diagnoses
A total of 17,487 COVID-19 patients were propensity matched with VRI patients and 15,694 individuals were propensity matched with non-infected controls.
When compared to non-infected controls, COVID-19 infection was a significant and positive predictor, for a diagnosis of palpitations (odds ratio, OR = 1.32, 95% CI 1.17 – 1.49), hair loss (OR = 1.32), fatigue (OR = 1.13), chest pain (OR = 1.10), dyspnoea (OR = 1.09), joint pain (OR = 1.08) and obesity (OR = 1.08). Moreover, the odds ratios were also significantly elevated for these conditions when compared to the VRI group.
However, there were notable differences for some recognised post COVID-19 condition symptoms. For example, there was no difference between COVID-19 and the VRI group for anxiety/depression, myalgia, insomnia and anosmia. While there was a significantly elevated risk of cognitive impairment when comparing COVID-19 and the VRI group, there was no difference between COVID-19 and non-infected controls.
The authors concluded n how infection with COVID-19 was not more significantly associated with an increased risk of some recognised post COVID-19 conditions compared to other common viral infections.
Baskett WI et al. COVID-Specific Long-Term Sequelae in Comparison to Common Viral Respiratory Infections: An Analysis of 17,487 Infected Adult Patients. Open Forum Infect 2022