New research this week appears to confirm the suspicion that the coronavirus can infect many parts of the human body, not just the respiratory system. It also found that the virus can sometimes remain in the body even after a person’s initial symptoms have subsided. Preliminary findings may shed light on the complex chronic condition known as the long virus that some survivors suffer from.
SARS-CoV-2 is primarily a respiratory virus, like influenza or other human coronaviruses. In mild cases, its severe symptoms tend to affect the upper respiratory tract, while more severe cases are associated with pulmonary infection and pneumonia. But evidence from the lab and patients suggests that the virus can travel throughout the body and infect other tissues as well, thanks to the receptors it uses to hijack cells. Recently, for example, scholars have found Evidence that the coronavirus can easily infect fat and immune cells.
The scientists behind this new research, mostly from the National Institutes of Health, say their research is the most comprehensive view yet into how well the coronavirus can infect different parts of the human body and brain. To do this, researchers performed complete autopsies on the bodies of 44 people who had contracted the coronavirus. In all but five cases, infection was directly involved in the person’s death.
Overall, the team found copious signs of coronavirus outside of the respiratory tract, both early and late in the infection. Its presence was certainly higher in the airways and lungs. But they also found evidence of infection in the cardiovascular tissues of nearly 80% of patients. in the tissues of the gastrointestinal tract 73% of patients and in muscle, skin, fat and peripheral nervous tissue 68% of patients. In all of the 85 body parts and body fluids they studied, the virus could be found – at least some of the time – in 79 of them, including the brain. They found traces of viral RNA throughout the body and brain months after symptoms began, up to 230 days in the case of one patient.
The authors wrote in their research paper, which was released as Prepress Sunday but is under review for publication in the journal Nature, according to Bloomberg News.
There are important limitations to this research. For example, cases clearly tend to involve people who are seriously ill with the COVID-19 virus. The authors noted that even in the few cases where someone has mild or no symptoms associated with the virus, the virus can still be found throughout the body. The study was also conducted between April 2020 and March 2021, a time period when relatively few people were vaccinated. So it’s possible that those with some immunity might prevent the virus from infecting the body just as it did in these patients (there was no mention of anyone vaccinated in the paper). The emergence of several new variants of the virus, such as Delta and Omicron, since March may complicate the picture.
All that said, the results give us a clearer picture of how acute infection with SARS-CoV-2 works and how it can continue to cause problems after the initial illness appears to be over. some experts Believe At least some cases of COVID-19 can be attributed to persistent infection. But while these findings provide strong evidence for a long-term infection, they also raise new questions.
For example, the team found little evidence that the presence of the virus outside the lungs was associated with direct inflammation or other virus-related infections of cells, even in persistent infections. This is key because inflammation is one of the most common ways the body can chronically damage itself, and many experts believe it plays a major role in the symptoms of COVID-19. The authors note that in some persistent infections, the virus may be too defective to continue reproducing, which may explain why the body does not respond to it like a typical infection. This discovery does not rule out the possibility that the virus will continue to cause harm when it remains in the body, but it does add a new wrinkle to the puzzle of Covid-19 disease that scientists will have to study further.