Respondents to global survey report 205 symptoms across 10 organ systems after infection

Many people suffering from “long Covid” are still unable to work at full capacity six months after infection, a large-scale survey of confirmed and suspected patients has found.

While Covid-19 was initially understood to be a largely respiratory illness from which most people would recover within two or three weeks, as the pandemic wore on increasing numbers reported experiencing symptoms for months on end.

These long haulers – with symptoms affecting organs ranging from the heart to the brain – have no real explanation and no standardised treatment plan for their long-term condition. There is no consensus on the scale and impact of long Covid but emerging data is concerning.

In one of the largest studies yet, which has not been peer reviewed, Patient Led Research for Covid-19 (a group of long Covid patients who are also researchers) surveyed 3,762 people aged 18 to 80-plus from 56 countries who responded in nine different languages to 257 different questions.

Two-hundred and five symptoms across 10 organ systems were recorded, with 66 symptoms traced over seven months. On average, respondents experienced symptoms from nine organ systems.Advertisement

“This is a chapter that has not yet been written in the medical textbooks, and barely any major research papers yet published. Part of the progress here is simply inputting large numbers and stats to the existing anecdotal sense of what’s been happening, while aspects feel really quite novel. Nobody can address the condition until we’re better able to narrate what’s happening,” said Danny Altmann, a professor of immunology at Imperial College London.

The analysis was limited to respondents with illnesses lasting longer than 28 days, whose onset of symptoms occurred before June 2020, allowing examination of symptoms over an average six months’ duration.

Roughly 65% of respondents (2,454) reported experiencing symptoms for at least six months. The most likely symptoms to persist after six months included fatigue, post-exertional malaise, cognitive dysfunction (“brain fog”), neurological sensations, headaches, memory problems, insomnia, muscle aches, palpitations, shortness of breath, dizziness/balance issues, and speech and language problems.

Nearly 86% of respondents experienced relapses, most commonly triggered by physical activity, stress, exercise and mental activity.

Other less common symptoms, such as new allergies, facial paralyses, seizures, impaired vision or hearing were important targets for further investigation, said Altmann.

Memory and cognitive dysfunction, experienced by more than 85% of respondents, were the most pervasive and persistent neurological symptoms. They were equally common across all ages and had a substantial impact on respondents’ ability to work, the authors found.

Forty-five per cent of respondents reported requiring a reduced work schedule compared with pre-illness, while roughly 22% were not working at the time of the survey due to their health conditions.

But the findings must be interpreted with caution. The majority of respondents were English speaking, white and of higher socioeconomic status. Most participants reported having at least one pre-existing condition such as allergies, migraine and asthma. Fewer than a third of respondents in the survey also had a confirmed Covid-19 infection.

“There may be differences in terms of … those with confirmed infection and those without,” said Dr Tim Nicholson, who is part of a multidisciplinary team at King’s College hospital setting up NHS-funded clinics for long Covid.

Respondents were recruited from support groups, so the data is not necessarily representative of the general population, or people from more deprived backgrounds that are at higher risk of getting Covid, said Nisreen Alwan, an associate professor in public health at the University of Southampton.

“People who recover from long Covid are less likely to complete the survey limiting the comparison of those who fully recover to those who don’t.”

The enduring neurological problems that hospitalised Covid patients can experience have prompted calls for doctors to monitor patients for months after they are discharged.

Neurologists at the University of Brescia in Italy found that a third of 165 former Covid patients recalled for neurological assessment had problems six months after leaving hospital. Their symptoms varied widely from memory and attention issues to sleep disorders, fatigue, tremors and a loss of the sense of smell.

Standard examinations found nearly 40% of the patients had neurological abnormalities that appeared more severe in those hit hardest by the disease. To take account of pre-existing conditions, the doctors assessed the patients in hospital and checked their medical records, but some patients may still have had undiagnosed cognitive problems before they became infected.

In a write-up of the research, which has yet to be peer reviewed and published in a medical journal, the doctors argue that long-term neurological problems seem common even in patients with less severe disease. The findings highlight “the importance of long-term follow-up programmes to properly care for patients” and to nail down the “real impact of Sars-CoV-2 infection on brain health status that is still uncertain”.