Long COVID symptoms can improve, but their resolution is slow and imperfect
- Written by Suman Majumdar, Chief Health Officer, Burnet Institute
Around 5–10%[1] of people who get infected with SARS-CoV-2 will experience symptoms that persist way beyond the initial acute period, a clinical syndrome we are learning more about, known widely as long COVID.
Shortness of breath, brain fog, lethargy and tiredness, loss of smell or taste are common features of long COVID[2], as is the development of new conditions such as diabetes, heart disease, stroke, depression and dementia.
But how long is the “long”? If and when do symptoms resolve?
Read more: When does COVID become long COVID? And what's happening in the body when symptoms persist? Here's what we've learnt so far[3]
A recent study[4] has examined this in detail, following people for two years after their infection. This and other recently published studies on long COVID show that while symptoms do resolve in many people, their resolution is slow and imperfect.
What did the study find?
The key work, led by Ziyad Al-Aly[5], examines the effect of SARS-CoV-2 two years after infection in a large group of US veterans. The researchers followed 139,000 people with COVID and almost six million uninfected controls for two years, tracking deaths, hospitalisations and 80 long-term impacts of COVID, categorised into ten organ systems.
They found that people who were initially hospitalised with COVID were 1.3 times more likely to die and 2.6 times more likely to be hospitalised again, compared to the control group (people without COVID), over the two years. After two years, this “hospitalised” group remained at increased risk of 50 conditions.
People who had milder COVID (who weren’t hospitalised with their initial COVID infection) had an increased risk of death for up to six months and increased risk of hospitalisation for up to 18 months. However, at two years, they remained at increased risk of 25 conditions.
So, while people who were initially hospitalised for COVID had worse outcomes over the two-year follow-up, there was still a substantial burden of illness in people who initially had milder COVID. This included a risk of clots and blood disorders, lung disease, fatigue, gut disorders, muscle and joint disorders and diabetes.
