Until now, the main cause of death from Covid-19 has been attributed to simultaneous infections such as bacterial pneumonia or inflammation caused by exaggerated immune system response But now a new study suggests that the accumulation of coronavirus in the lungs has been the biggest cause of death during the pandemic.
A study, led by researchers from the Grossman School of Medicine, New York University and published today in Nature Microbiology, has shown that people who died from covid-19 had in their lungs an amount of virus or viral load about 10 times higher than seriously ill patients who survived the disease.
“Our results suggest that the body’s inability to cope with the large number of viruses that infect the lungs is largely responsible for COVID-19 deaths in the pandemic,” says the study’s lead author, Imran Sulaiman, Adjunct Professor in the NYU Langone Health Department of Medicine.
So far, the coronavirus has killed more than 4 million people worldwide; people connected to mechanical respirators have the worst prognosis: 70% do not overcome the disease.
Experts have always attributed the high mortality of other viral pandemics, such as the Spanish flu of 1918 and the swine flu of 2009, to secondary bacterial infections but it was not clear if this also happened to people with covid-19.
The aim of the new study was to clarify the role of secondary infections, viral load and immune cell populations in mortality from covid-19, according to Sulaiman.
The research focused on the detailed study of the lower respiratory tract in patients with coronavirus.
To do this, bacterial and fungal samples were collected from the lungs of 589 men and women hospitalized at NYU Langone (in Manhattan) and on Long Island. All required mechanical ventilation.
142 patients underwent bronchoscopy to clear the airways and the amount of virus contained in the samples was analyzed and the microbes present were identified by studying small fragments of the germs’ genetic code.
The study authors also looked at the type of immune cells and compounds located in the lower respiratory tract.
The study revealed that those who died had an average of 50% less production of a type of immune chemical that targets the coronavirus compared to covid-19 patients who survived the disease.
These personalized proteins are part of the adaptive immune system of the body, a subset of cells and chemicals that “remember” the newly found invading microbes, leaving the body better prepared for future exposures.
“These results suggest that a problem with the adaptive immune system prevents it from effectively fighting the coronavirus. If we could identify the origin of this problem, we could find an effective treatment that strengthens the body’s defenses,” says the study’s co-lead author and professor of the NYU Langone, Leopoldo Segal.
The action protocols of the United States Centers for Disease Control and Prevention do not recommend the use of antiviral As the remdesivir in severely ill patients on mechanical ventilation but Sulaiman believes that in light of the study results, these drugs could be a valuable tool in treating patients.
Eddie is an Australian news reporter with over 9 years in the industry and has published on Forbes and tech crunch.