THE ESSENTIAL
- An American study published in December 2022 shows that patients who contracted a severe form of Covid-19 showed a decline in their cognitive performance that mimicked accelerated ageing.
- We talk about long covid when the patient still feels symptoms beyond 4 weeks of infection.
Researchers from the University of Minnesota wanted to determine the location and persistence of Sars-CoV-2 in the body. To do this, they carried out the autopsies of 44 people who died of Covid-19.
Sars-CoV-2: traces of the virus in the brain
For this study presented in Nature, tissues were taken from the 44 people who died of Covid-19. A brain sample was taken from 11 of them.
Not surprisingly, the analysis has shown that Sars-CoV-2 mainly infects and damages the airways and lung tissue. On the other hand, more surprisingly, traces of the virus have also been found in other parts of the body. Researchers found virus RNA in 84 areas and body fluids, including the brain, up to 230 days (nearly eight months) after the onset of symptoms for one case.
While coronavirus RNA and proteins were spotted in the hypothalamus and cerebellum of one patient, as well as the spinal cord and basal ganglia of two others, the scientists noted that there was little damage to the brain tissue, “despite a significant viral load.”
Furthermore, viable Sars-CoV-2 was isolated in 25 of the 55 samples tested (45%). It has been found in various tissues, including the brain, heart, lymph nodes, digestive tract, adrenal gland, and eyes.
Useful work also to fight the long covid
The lead author of the study, Dr. Daniel Chertow, explained in a University of Minnesota statement that prior to his work, “the thinking on the ground was that Sars-CoV-2 was primarily a respiratory virus.”
For him, the discovery of the presence of Sars-CoV-2 throughout the body helps to better understand the development of the long covid. The expert assures that his work, disclosed to his colleagues several months ago, has made it possible “to explore the relationship between heavily infected body tissue and long-term Covid, i.e. symptoms that persist for weeks and months after infection.”
