Coronavirus disease (Covid-19) patients who experience prolonged symptoms have reported more than 200 symptoms across 10 organ systems, according to a global study published on Thursday. The researchers conducted an online survey to characterise the symptom profile and time course in patients with suspected and confirmed Long Covid.
They analysed the responses from 3,762 participants from 56 countries with confirmed or suspected Covid-19, making the study the largest to date of ‘long-haulers’. The data were collected from September 6, 2020, to November 25, 2020. The researchers estimated the prevalence of 203 symptoms in 10 organ systems and traced 66 symptoms over seven months.
The study, published in The Lancet’s EClinicalMedicine, suggests that the time of recovery for the majority of patients exceeded 35 weeks. During the illness, the patients experienced 55 symptoms on average across nine organ systems. As per the study, the most frequent symptoms after six months were fatigue, post-exertional malaise — worsening of symptoms after physical or mental exertion — and cognitive dysfunction, which varied in their prevalence over time.
Other symptoms included visual hallucinations, tremors, itchy skin, changes to the menstrual cycle, sexual dysfunction, heart palpitations, bladder control issues, shingles, memory loss, blurred vision, diarrhoea, and tinnitus.
“While there has been a lot of public discussion around long Covid, there are few systematic studies investigating this population,” said Athena Akrami, a neuroscientist at University College London in the UK, and senior author of the study.
“Relatively little is known about its range of symptoms, and their progression over time, the severity, and expected clinical course (longevity), its impact on daily functioning, and expected return to baseline health,” she added.
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The researchers are calling for clinical guidelines on assessing Long Covid to be significantly widened beyond currently advised cardiovascular and respiratory function tests. The researchers said that the study highlights the importance of slowing the spread of the virus through validated public health measures and vaccinations and the necessity of a robust safety net, including sick leave, family leave, disability benefits, and workplace protections and flexibilities.
“Memory and cognitive dysfunction, experienced by over 85 per cent of respondents, were the most pervasive and persisting neurologic symptoms, equally common across all ages, and with substantial impact on work,” said Akrami.
Due to the retrospective nature of the study, the researchers acknowledged the possibility of recall bias, which could impact the reliability of symptom prevalence estimates. Highlighting the limitations of the study, they said that both overreporting and underreporting of symptoms are possible. They also said that the study may not be representative of the entire Long Covid population or their experiences.
(With PTI inputs)