Experts suggest routine lab tests may be ‘unreliable’ for diagnosing long Covid.
A new study supported by the US-based National Institutes of Health (NIH) has shined a light on the difficulties of identifying and diagnosing sufferers of long Covid based on typical examinations.
“Our challenge is to discover biomarkers that can help us quickly and accurately diagnose long Covid to ensure people struggling with this disease receive the most appropriate care as soon as possible,” said Dr David Goff, director for the Division of Cardiovascular Sciences at the NIH’s National Heart, Lung, and Blood Institute.
“Long Covid symptoms can prevent someone from returning to work or school, and may even make everyday tasks a burden, so the ability for rapid diagnosis is key.”
While most Covid sufferers feel better within a couple of days or weeks, some experience its symptoms for far longer. This is what’s referred to as ‘long Covid’ – encompassing a wide series of symptoms that may persist for months or even years.
Extreme tiredness, feeling out of breath, brain fog and even heart palpitations are among its most common signs. Others have reported a prolonged loss of smell and chest pain too.
Within the NIH’s study, researchers were keen to see whether Covid-19 leads to a change in ‘biomarkers’ found in the human body. In a nutshell, these are molecules within tissues or bodily fluids that indicate the presence of a disease or condition.
Although these are widely used by the medical community to diagnose patients, no clinical biomarkers of long Covid have been validated or found. So, as of now, diagnosing the condition is quite challenging, requiring extensive lab work, medical history research and various tests.
As part of their study, more than 10,000 adults were recruited at 83 sites across the US.
Among them, 8,746 had previously suffered from different variants of Covid, while 1,348 had never been infected. These participants then completed several surveys, blood tests, urine tests and physical examinations before scientists monitored their lives through a two-year study period.
Unfortunately, lab tests showed very little differences in biomarkers between those who’d previously been infected and those who hadn’t. Although some patients experienced an increase in blood sugar levels, the cause was soon ruled out as diabetes.
“Future work will use RECOVER’s biobank of cohort samples such as blood and spinal fluid, to develop more novel laboratory-based tests that help us better understand the pathophysiology of long COVID,” concluded, Professor Kristine Erlandson who co-authored the study.