The main factor in severe cases of the course of COVID-19, leading to death, was the high concentration of the pathogen in the lungs, scientists from New York University found. The research is published in the journal Nature.
“Our results show that a large part of the deaths from COVID-19 is the body’s inability to cope with the large amount of virus infecting the lungs,” said one of the authors, Imran Suleiman, MD, associate professor in the Department of Medicine at New York University.
Scientists collected samples of bacteria and fungi from the lungs of 589 critically ill patients. In 142 people who, in addition to mechanical ventilation, required bronchoscopy, specialists also analyzed the number of viral particles in the lower respiratory tract and determined which microorganisms were there.
The study found that the viral load, or the number of viral particles, in the lungs of deceased patients was, on average, ten times higher than that of those who survived.
In parallel, scientists have found no evidence that the cause of death was a secondary bacterial infection. At the same time, they admitted that this could be due to the fact that almost all seriously ill patients received a course of antibiotics.
The researchers also found no confirmation that the virus can force the immune system to attack its own lung tissue, leading to severe inflammation and is considered the leading cause of death in COVID-19. They found that in all the cases studied, the strength of the immune response was proportional to the viral load. In deceased patients, on average, the development of an immune response aimed at “remembering” the coronavirus was reduced by 50%.
Due to the fact that the high mortality rate of patients on mechanical ventilation (more than 70%) is often attributed to secondary bacterial infections, the emphasis in treatment is on antibiotics, the study says. However, its results suggest that antiviral drugs such as remdisivir may play a critical role in treatment, the scientists noted.
Leopoldo Segal, head of the study, assistant professor of medicine at New York University, warned that his team only studied patients who survived the first two weeks of hospitalization. It is possible that bacterial infections are more influencing mortality from COVID-19 in its early stages.
In Russia, more than 700 people die every day from coronavirus for almost two months. Several anti-records were broken over the summer, the last maximum was recorded on August 26, when 820 people died.
The number of people infected per day has been gradually decreasing since mid-July and on August 31 it was less than 18 thousand people. According to doctors interviewed by RBC, an increase in mortality with a decrease in morbidity is due to the fact that mortality rates will change later: now people who fell ill a few weeks ago are dying.
