LONDON: Patients who experience long COVID have reported more than 200 symptoms across 10 organ systems in what is dubbed the largest international study of COVID-19 "long-haulers" to date, published on Thursday.
The study, led by University College London (UCL) scientists together with a patient-led research collaborative, found the most common symptoms of long-term COVID effects as fatigue, post-exertional malaise (the worsening of symptoms after physical or mental exertion), and cognitive dysfunction, often called brain fog.
Of the diverse range of symptoms, others 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; hence 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, said Dr Athena Akrami, neuroscientist at the Sainsbury Wellcome Centre at UCL and senior of the study published in the Lancet's 'EClinicalMedicine'."
"In this unique approach, we have gone directly to long haulers' around the world in order to establish a foundation of evidence for medical investigation, improvement of care, and advocacy for the long COVID population. This is the most comprehensive characterisation of long COVID symptoms, so far," she said.
For the study, patient researchers connected through the Body Politic online COVID-19 support group and created a web-based survey designed to characterise the symptom profile and time course in patients with confirmed or suspected long COVID, along with the impact on daily life, work, and return to health.
With responses from 3,762 eligible participants from 56 countries, the researchers identified a total of 203 symptoms in 10 organ systems; of these, 66 symptoms were tracked for seven months.
The research team, who have all had or continue to have long COVID, are now calling for clinical guidelines on assessing long COVID to be significantly widened beyond currently advised cardiovascular and respiratory function tests to include neuropsychiatric, neurological, and activity intolerance symptoms.
The authors also advocate that a national screening programme, accessible to anyone who thinks they have long COVID, should be undertaken.
Given the heterogeneous and diverse make-up of symptoms that affect multiple organ systems, it is only by detecting the root cause that patients will receive the correct treatment, they note.
Dr Akrami added: "For the first time this study shines a light on the vast spectrum of symptoms, particularly neurological, prevalent and persistent in patients with long COVID."
"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."
Headaches, insomnia, vertigo, neuralgia, neuropsychiatric changes, tremors, sensitivity to noise and light, hallucinations (olfactory and other), tinnitus, and other sensorimotor symptoms were also all common, and may point to larger neurological issues involving both the central and peripheral nervous system.
The survey was open to those aged 18 or over who had experienced symptoms consistent with COVID-19, including those with and without a positive SARS-CoV-2 test.
It consisted of 257 questions.
In order to characterise long COVID symptoms over an extended duration, analysis of survey data was limited to respondents with illnesses lasting longer than 28 days and whose onset of symptoms occurred between December 2019 and May 2020, allowing analysis of symptoms from week one to month seven.