More than three quarters of coronavirus patients have at least one ongoing symptom six months after initially becoming unwell, according to a new study.
The research looked at the long-term effects of Covid-19 on people admitted to hospital in Wuhan, China, and found that the most common symptom to persist is fatigue or muscle weakness, in 63% of patients.
Patients also frequently experience sleep difficulties (26%), and anxiety or depression was reported among 23% of patients, according to the study.
Researchers found patients who were severely ill in hospital more often had impaired lung function and abnormalities detected in chest imaging – which could indicate organ damage – six months after symptom onset.
The new study looked at patients who had been treated in Wuhan
The study, published in The Lancet, found that levels of neutralising antibodies fell by more than half (52.5%) after six months in 94 patients whose immune response was tested at the peak of the infection.
Researchers suggest this raises concerns about the possibility of being re-infected by the virus.
Professor Bin Cao, from the National Centre for Respiratory Medicine, China-Japan Friendship Hospital and Capital Medical University, said: “Because Covid-19 is such a new disease, we are only beginning to understand some of its long-term effects on patients’ health.
“Our analysis indicates that most patients continue to live with at least some of the effects of the virus after leaving hospital, and highlights a need for post-discharge care, particularly for those who experience severe infections.
Medical workers in protective suits attend to coronavirus patients at the intensive care unit (ICU) of a designated hospital in China
“Our work also underscores the importance of conducting longer follow-up studies in larger populations in order to understand the full spectrum of effects that Covid-19 can have on people.”
The new study included 1,733 Covid-19 patients, with a median age of 57, who were discharged from Jinyintan Hospital in Wuhan between January 7 and May 29 last year.
Follow-up visits were done from June 16 to September 3, 2020, and the median follow-up time was 186 days.
All patients were interviewed face-to-face using questionnaires to evaluate their symptoms and health-related quality of life.
They also underwent physical examinations, lab tests, and a six-minute walking test to gauge patients’ endurance levels.
In addition, 94 patients whose blood antibody levels were recorded at the height of the infection as part of another trial received a follow-up test.
Medical workers in Wuhan, China, where the virus originated
At follow-up, 76% of patients (1,265/1,655) reported at least one ongoing symptom.
Fatigue or muscle weakness was reported by 63% (1,038/1,655), while 26% (437/1,655) had sleep difficulties and 23% (367/1,733) experienced anxiety or depression.
Of the 390 patients who underwent additional testing, 349 completed the lung function test.
Patients with more severe illness commonly had reduced lung function, with 56% (48/86) of those at severity scale five to six – who required ventilation – experiencing reduced flow of oxygen from the lungs to the bloodstream.
For patients at severity scale four – who required oxygen therapy – and those at scale three (who did not require oxygen therapy) the figures were 29% (48/165) and 22% (18/83), respectively.
Studies into the effects of the virus are still ongoing
Patients with more severe disease performed worse in the six-minute walking test, with 29% of those at severity scale five to six walking less than the lower limit of the normal range, compared with 24% for those at scale three, and 22% for scale four.
Researchers also found that some patients went on to develop kidney problems post-discharge.
Tests revealed that 13% (107/822) of patients whose kidney function was normal while in hospital had reduced kidney function in follow-up.
The researchers say that as the number of participants with antibody test results both at acute phase and follow-up was limited, larger samples are needed in the future to clarify how levels of antibodies against the virus change over time.
They add that further work is also needed to compare differences in outcomes between inpatients and outpatients, as patients with mild Covid-19 symptoms who stayed in temporary Fangcang shelter hospitals were not included in the study.