New Delhi: Viral buildup in the lungs is the likely driver behind the steep mortality rates seen in the COVID-19 pandemic, according to a study published on Tuesday.
Researchers at New York University (NYU) Grossman School of Medicine, US, showed that people who died of COVID-19 had on average 10 times the amount of virus in their lower airways as did severely ill patients who survived their illness.
The finding, published in the journal Nature Microbiology, contradicts previous theories that simultaneous infections, such as bacterial pneumonia or overreaction of the body’s immune defence system, played major roles in heightened risk of death.
“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,” study lead author Imran Sulaiman, an adjunct professor at NYU Langone Health was quoted as saying.
- 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.
- Current guidelines from the Centers 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.
- No evidence to suggest 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 and consequently COVID-19 deaths.
- The strength of the immune response appeared proportionate to the amount of virus in the lungs.
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.