Persistent virus
One of the most dangerous causes of long COVID is a persistent virus, as Proal discovered in late 2021 after an autopsy study that caught her attention. Researchers from the U.S. National Institutes of Health described their own analysis of tissues from almost 44 people who had also been infected.
While most of them died from COVID-19, five suffered a mild, asymptomatic infection that later succumbed to something else. All 44 harbored the viral RNA in their bodies, but their brain, muscles, gut, and lungs were also affected. Many of these organs later showed evidence of replicating the virus.
Other studies currently try to establish if replicating copies of the virus exist by comparing the ones of long COVID and other cohorts, which include people who recovered from COVID-19. In one of them, gastroenterologist Herbert Tilg at the Medical University of Innsbruck tried to look for molecular traces of the virus in the gut, which is one of the best hunting grounds for all researchers who are currently studying SARS-CoV-2.
If you wonder why, I’ll tell you: the gut is far easier for doctors to access than any other organ, including the lungs and brain, and it is believed that it can harbor viruses better than blood, which has the tendency to clear any pathogens way faster.
