The team at Columbia University Irving Medical Center in New York - one of the hospitals flooded with patients in the spring - shared their own experiences and gathered reports from other medical teams around the world.
Their full picture shows that the coronavirus attacks practically every major system in the human body, directly damaging organs and causing blood to clot, the heart to lose its healthy rhythm, the kidneys to shed blood and protein, and the skin to burst. in rashes. It causes headache, dizziness, muscle pain, stomach pain and other symptoms as well as classic respiratory symptoms like cough and fever.
"Doctors should view COVID-19 as a multisystem disease," said Dr. Aakriti Gupta, a Columbia cardiologist who worked on the exam, in a statement. "There is a lot of news regarding clotting, but it is also important to understand that a substantial proportion of these patients suffer from kidney, heart and brain damage, and doctors need to treat these conditions with respiratory disease."
Much of the damage caused by the virus appears to come from its affinity for a receptor - a kind of molecular gateway in cells - called ACE2. The cells lining the blood vessels, the kidneys, the hepatic ducts, the pancreas, the intestinal tract and lining the respiratory tract are all coated with ACE2 receptors, which the virus can use to catch and infect the cells, writes the Columbia team in their review, published in the journal Nature Medicine.
"These results suggest that damage to multiple organs may occur at least in part due to direct damage to viral tissue," the team wrote.
Coronavirus infection also activates the immune system. Part of this response includes the production of inflammatory proteins called cytokines. This inflammation can damage cells and organs and the so-called cytokine storm is one of the causes of severe symptoms.
"This virus is unusual and it is difficult not to step back and not be impressed by the number of manifestations it has on the human body," said fellow research fellow Dr Mahesh Madhavan in a statement. cardiology who worked on the journal.
The effects of blood clotting appear to be caused by several different mechanisms: direct damage to the cells lining the blood vessels and interference with the various clotting mechanisms in the blood itself. Low oxygen levels in the blood caused by pneumonia can make the blood more likely to clot, the researchers said.
These clots can cause strokes and heart attacks, or can lodge in the lungs or legs. They clog the kidneys and interfere with the dialysis treatments needed by the sickest patients.
Damage to the pancreas can worsen diabetes, and diabetes patients have been shown to be at the highest risk for serious illness and death from coronavirus.
The virus can directly damage the brain, but some of the neurological effects are likely to come from treatment. "COVID-19 patients can be intubated for two to three weeks; a quarter require ventilators for 30 days or more," said Gupta.
"These are very prolonged intubations, and patients need a lot of sedation. Delirium in intensive care was a well-known disease before COVID, and hallucinations may be less of an effect of the virus and more of an effect of prolonged sedation. "
The virus affects the immune system, depleting the T cells that the body usually deploys to fight viral infections. "Lymphopenia, a marker of altered cellular immunity, is a cardinal laboratory finding reported in 67 to 90% of patients with COVID-19," the researchers wrote.
Doctors must treat all of these effects when patients with coronaviruses come to the hospital, the Columbia team said.
There is some good news.
"The gastrointestinal symptoms may be associated with a longer duration of the disease but have not been associated with increased mortality," the researchers wrote. Many skin effects, such as purple and swollen purple rashes and "Covid toes", also go away on their own.
