Besides dealing with everything else that COVID-19 has thrown our way, medical experts are working hard to get a better idea of what's causing long COVID – a condition where symptoms persist for months after a COVID-19 infection.
A new study has identified 203 different long COVID symptoms across 10 different organ systems in the body, highlighting just how widespread and varied the affliction is and how it can interfere with many different aspects of daily life.
The researchers behind the study – who have all experienced, or continue to experience, long COVID themselves – are calling for national screening programs to catch more cases of long COVID, as well as more accurate clinical guidelines for describing the condition.
"While there has been a lot of public discussion around long COVID, there are few systematic studies investigating this population," says neuroscientist Athena Akrami from University College London. "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."
"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."
With a total of 3,762 people quizzed across 56 countries, the international study is the biggest and most comprehensive look yet at how 'long haulers' continue to have problems way beyond the normal timescale of COVID-19.
The most commonly reported symptoms were fatigue, post-exertional malaise (symptoms getting worse after physical or mental effort), and cognitive dysfunction or 'brain fog'. Other symptoms included visual hallucinations, tremors, sexual dysfunction, memory loss, and diarrhea – a whole range of physical and cognitive health issues.
On average, participants reported 55.9 symptoms each, across 9.1 organ systems. Of the 3,762 respondents with long COVID, 2,454 had experienced symptoms for at least six months. All that takes a toll: 45.2 percent of participants said they had reduced their working hours, while 22.3 percent were not working at all at the time of the survey.
"By seven months, many patients have not yet recovered (mainly from systemic and neurological/cognitive symptoms), have not returned to previous levels of work, and continue to experience significant symptom burden," write the researchers in their published paper.
There's a lot that we still don't know about long COVID, though the picture is slowly becoming clearer. Symptoms seem to fade after vaccination, but only for some patients, while research has also shown that women are at greater risk of long COVID.
Around 1 in 10 people who get COVID-19 are thought to still be suffering from some symptoms more than 12 weeks after a positive test result. Considering the spread of the pandemic around the globe, we're potentially talking about millions of people.
The researchers want to see tests covering neurological and neuropsychiatric symptoms, as well as the current cardiovascular and respiratory ones, to catch more people who are continuing to struggle with COVID-19.
"There are likely to be tens of thousands of long COVID patients suffering in silence, unsure that their symptoms are connected to COVID-19," says Akrami.
The research has been published in EClinicalMedicine.