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Scientists funded by the federal government have proposed a definition of long Covid based on symptoms identified in a big study published Thursday within the Journal of the American Medical Association.
The definition relies on 12 symptoms that almost all separate individuals with long Covid six months or more after their infection from individuals who didn’t have the coronavirus.
Because the very early days of the pandemic, many individuals have suffered myriad sometimes debilitating symptoms that persist long after they were infected with Covid-19.
Patients adopted the name long Covid. Scientists call the condition post-acute sequelae, or PASC.
But there still is not any systematic, universally accepted definition of long Covid for research, and which could function the muse for future tools to diagnose the condition.
“It’s really attempting to provide you with a concrete, replicable specific definition for long Covid,” said Dr. Leora Horwitz, writer of the study and a professor at NYU Grossman School of Medicine.
The study funded by the National Institutes of Health examined nearly 10,000 participants across 85 hospitals, health centers and community centers in 33 states.
Greater than 8,600 patients who had Covid were compared with greater than 1,100 who didn’t have the virus.
The research is a component of the NIH’s massive $1.15 billion RECOVER research initiative that goals to define long Covid, understand what causes the condition and develop treatments for it. RECOVER is an acronym for Researching COVID to Enhance Recovery.
Key symptoms
The symptoms that stood out probably the most amongst participants with long Covid included lack of smell and taste, post-exertional malaise, chronic cough, brain fog, thirst, palpitations, chest pain, fatigue, changes in sexual desire, dizziness, gastrointestinal issues, abnormal movements and hair loss.
The scientists assigned points based on how much each symptom distinguished participants with long Covid from those that didn’t catch the virus.
A participant who has 12 points or more is taken into account more likely to have long Covid.
Lack of smell and taste and post-exertional malaise, for instance, stood out greater than other symptoms, and had scores of 8 and seven points, respectively. Palpitations and dizziness, that are characteristic of long Covid, but that are also common symptoms in lots of other conditions, scored 2 points and 1 point, respectively.
Future clinical use
Horwitz, writer of the study, said the proposed definition of long Covid could help develop a technique for doctors to diagnose patients.
But Horwitz said the definition presented within the study is an early working one, still must be refined and is just not yet ready for clinical use.
Within the absence of a universally accepted definition, many long Covid patients have struggled to get appropriate health care, particularly early within the pandemic, because some symptoms are common to other conditions, which may make a diagnosis difficult.
There are not any tests that may diagnose long Covid based on markers within the blood. Scientists participating in RECOVER are attempting to grasp the underlying biology that causes long Covid, which could potentially result in such tests in the longer term.
Horwitz said the proposed definition could help create a rubric to diagnose patients with long Covid in a way much like Lupus. There isn’t any single blood test that may diagnose Lupus, so physicians also depend on a set of common symptoms to find out whether a patient has the disease.
Horwitz said the goal is to offer researchers a more systematic definition that might be used to reply questions on risk aspects and the way likely long Covid is after repeat infection and between different variants of the virus, amongst other issues.
Biological samples from the patients who developed long Covid through the study may very well be used to analyze what causes the condition and potentially help find treatments and guide enrollment in future clinical trials, in line with the study.
Long Covid more common before omicron
The study also found that long Covid was more common amongst people infected before the omicron variant swept the U.S. in December 2021.
About 17% of patients who enrolled greater than 30 days after their infection during omicron developed long Covid. Against this, about 35% of those infected before the omicron era developed long Covid.
But patients who were reinfected during omicron were more more likely to develop long Covid than those that reported one infection when the variant was surging. About 21% of those with repeat infections who enrolled after 30 days developed long Covid compared with 16% who caught Covid once.
Individuals who were fully vaccinated were less more likely to develop long Covid no matter once they were infected.
About 16% of participants up up to now on their shots who got infected during omicron developed long Covid, compared with 22% who didn’t receive their shots. Before omicron, 31% of individuals up up to now on their shots who got infected developed long Covid, compared with 37% who weren’t vaccinated.