An Oxford University study looking at the longer-term impact of Covid-19, so-called “long Covid”, has concluded that a large proportion of Covid-19 patients discharged from hospital are still experiencing symptoms of breathlessness, fatigue, anxiety and depression two to three months after contracting the virus.
The scientists carrying out the C-MORE study also detected abnormalities on magnetic resonance imaging (MRI) in multiple organs and have argued that persistent or chronic inflammation may be an underlying factor for these changes among Covid-19 survivors.
There are growing worries that long Covid could become a significant return-to-work challenge for occupational health practitioners. Research has suggested as many as one in 20 go on to develop long-term symptoms following catching the virus, with older women at most risk. The NHS is also establishing a network of specialist clinics to treat, and try to better understand, the condition.
The Oxford University study took 58 patients with moderate to severe laboratory-confirmed Covid-19, who had been admitted for treatment at the Oxford University Hospitals NHS Foundation Trust between March and May 2020.
The researchers also recruited 30 uninfected controls from the community, group-matched for age, sex, body mass index and risk factors such as smoking, diabetes and hypertension.
The participants underwent an MRI of their brain, lungs, heart, liver and kidneys; spirometry to test their lung function; a six-minute walk test; cardiopulmonary exercise test (CPET), as well as assessments of their quality of life, cognitive and mental health.
The study found that two to three months after the onset of the disease, 64% of patients experienced persistent breathlessness and 55% complained of significant fatigue.
On MRI, tissue signal abnormalities were seen in the lungs of 60% of the Covid-19 patients, in the kidneys of 29%, in the hearts of 26%, and the livers of 10%. Organ abnormalities were seen even in patients who had not been critically ill when admitted.
The scans also detected tissue changes in parts of the brain, and patients demonstrated impaired cognitive performance. Their ability to sustain exercise was also significantly reduced, although this was due to a combination of fatigue and lung abnormalities.
The study found patients were more likely to report symptoms of anxiety and depression, and a significant impairment in their quality of life compared to the controls.
Study co-lead Dr Betty Raman, of the Radcliffe Department of Medicine, said: “Whilst we have found abnormalities in multiple organs, it is difficult to know how much of this was pre-existing and how much has been caused by Covid-19.
“However, it is interesting to see that the abnormalities detected on MRI and exercise capacity in patients strongly correlated with serum markers of inflammation. This suggests a potential link between chronic inflammation and ongoing organ damage among survivors.”
Separately, the National Institute for Health and Care Excellence (NICE), the Scottish Intercollegiate Guidelines Network (SIGN) and the Royal College of General Practitioners (RCGP) have said they are developing guidelines on long Covid, or what they are terming “post-Covid syndrome”.
A guideline scope document was published in October, which defined post-Covid syndrome as “signs and symptoms that develop during or following an infection consistent with Covid-19 which continue for more than 12 weeks and are not explained by an alternative diagnosis.”
The condition usually presented with clusters of symptoms, often overlapping, which may change over time and could affect any system within the body. “Many people with post-Covid syndrome can also experience generalised pain, fatigue, persisting high temperature and psychiatric problems,” it added.
The full Oxford University paper can be found here.