According to a study published on Tuesday, viral buildup in the lungs is the likely cause of the Covid-19 pandemic’s high mortality rates.
Researchers from New York University’s (NYU) Grossman School of Medicine in the United States discovered that people who died from Covid-19 had 10 times the amount of virus in their lower airways as severely ill patients who survived their illness.
The researchers found no evidence implicating a secondary bacterial infection as the cause of the deaths, although they cautioned that this may be due to the frequent course of antibiotics given to critically ill patients.
“Our findings suggest that the body’s failure to cope with the large numbers of virus infecting the lungs is largely responsible for Covid-19 deaths in the pandemic,” said study lead author Imran Sulaiman, an adjunct professor at NYU Langone Health.
The researchers noted that current guidelines from the Centres for Disease Control and Prevention do not encourage the use of antivirals such as remdesivir for severely ill patients on mechanical ventilation.
However, the study results suggest that these medications may still remain a valuable tool in treating these patients, they noted.
Despite previous concerns that the virus may prompt the immune system to attack the body’s own lung tissue and lead to dangerous levels of inflammation, the researchers found no evidence that this was a major contributor to Covid-19 deaths in the group studied. They noted that the strength of the immune response appeared proportionate to the amount of virus in the lungs.
The coronavirus has so far killed over 4 million people worldwide. Those placed on mechanical ventilators in order to breathe fare particularly poorly.
Experts attribute the high mortality seen in other viral pandemics such as the Spanish flu in 1918 and swine flu in 2009 to a secondary bacterial infection. However, it remained unclear whether a similar issue afflicted people with Covid-19.
The latest study provides the most detailed survey of the lower airway environment in coronavirus patients, the researchers said. They collected bacterial and fungal samples from the lungs of 589 men and women who were hospitalised in the US, all of whom required mechanical ventilation.
