There is not one form of long Covid, but 4 different subtypes, according to a new study by Weill Cornell Medicine. They are distinguished by the symptoms that the patients manifest.
- We speak of long Covid when the patient still feels symptoms beyond 4 weeks after infection with Sars-CoV-2.
- According to Public Health France, 20% of people who had an infection with Sars-CoV-2 still presented the criteria for a long Covid 18 months after contamination.
It is estimated that around 30% of people who have been infected with Sars-CoV-2 develop long-term covid afterwards. A new discovery makes it possible to learn more about this disease which can persist for several months. There would be 4 different forms of long covid.
Long Covid: subtypes differentiated by symptoms
To better understand the long Covid, researchers from Weill Cornell Medicine gathered the medical records of nearly 35,000 American patients who tested positive for Sars-CoV-2 from March 2020 to November 2021 and then developed persistent signs of Covid-19. They created an algorithm capable of spotting patterns among symptoms. This tool allowed them to detect four different patterns:
- Long Covid affecting the cardiac and renal system : 34% of patients had this subform. The average age of the patients in this group was higher than that of the others (median age of 65 years). They were more likely to be male (49%), had a relatively high rate of hospitalization for Covid-19 (61%) and had relatively more existing pre-conditions. This group also had the highest proportion (37%) of patients who were affected by the coronavirus during the first major wave in the USA (March to June 2020).
- Long Covid resulting in trouble breathing, sleeping or anxiety : 33% of the patients followed suffered from this form of long covid. In addition to breathing and sleeping problems, they could complain of headaches and chest pains. 63% of patients were women with a median age of 51 years. The hospitalization rate for Covid was much lower (31%). Almost two-thirds of people in this group tested positive for Sars-CoV-2 in later waves (November 2020 to November 2021). Pre-existing conditions centered on respiratory problems such as chronic obstructive pulmonary disease and asthma.
- Covid long with musculoskeletal and nervous system symptoms : it represents 23% of cases. Patients were in the majority in this group (more than 60%).
- Covid long with a combination of digestive and respiratory symptoms : 10% of patients still affected by their coronavirus contamination presented this form of the disease. They were mostly women, too.
Better understand the mechanisms of the long Covid to better treat it
“Understanding the epidemiology of long Covid allows physicians to help patients understand their symptoms and prognoses and facilitates treatment,” explained Dr. Rainu Kaushal, chair of the Department of Population Health Sciences at Weill Cornell Medicine and co-author of the study published in early December in the journal NatureMedicine.
By highlighting the 4 subtypes of long Covid, the researchers noticed – that with the exception of the first pattern – women represented a significant majority of patients. “This gender difference in long Covid risk is consistent with previous research, but so far very few studies have tried to discover the mechanisms underlying it”explained Dr. Fei Wang, co-author of the work and professor at Weill Cornell Medicine.
The team is thus continuing its research to more precisely define the symptoms of long Covid and identify the risk factors and possible treatments.
