Researchers from the United States have shown that the most likely explanation of the high mortality rate from COVID-19 is the excessive accumulation of SARS-COV-2 particles in light patients. The article of scientists was published in the journal Nature Microbiology.
Specialists from New York University collected samples of bacteria and fungi from the lungs of 589 patients of the university hospital in critical condition. In 142 patients, in addition to artificial ventilation, the lungs also needed bronchoscopy, specialists also analyzed the number of viral particles in the lower respiratory tract and with the help of metagenomic methods was determined by the microbes. In addition, the authors of the study determined immune cells prevailing in the body.
It turned out that the viral load – the number of viral particles – in the lungs in the patients dead from the coronavirus, was on average ten times more than that of survivors. At the same time, the researchers did not find evidence that autoimmune reactions were influenced by the outcome of the disease or secondary bacterial infections – which are called one of the main causes of high mortality during the Pandemic of the “Spanish” influenza at the beginning of the 20th century. The power of the immune response, the researchers note, was proportional to the number of virus particles in the lungs. In addition, 50 percent of the cases of the patients who died from coronavirus were reduced by the level of the adaptive immune system of the protein responsible for the “memorization of” microbes.
At the same time, the authors note that only patients who survived the first two weeks of hospitalization were studied in the study. It is possible, they recognize that secondary bacterial infections and autoimmune reactions are more affected by the mortality from COVID-19 at the early stage.