A buildup of coronavirus in the lungs is likely tied to high COVID-19 mortality rates, according to a study published Aug. 31 in Nature Microbiology.
Researchers at New York City-based NYU Grossman School of Medicine collected bacterial and fungal samples from the lungs of 589 COVID-19 patients hospitalized at NYU Langone facilities. All required mechanical ventilation. For 142 patients who had a bronchoscopy procedure to clear their air passages, investigators analyzed the amount of virus in lower airways. Study authors also surveyed the type of immune cells and compounds in their lower airways.
Four study findings:
1. People who died from COVID-19 had, on average, 10 times the viral load in their lower airways compared to severely ill patients who survived.
2. Those who died had an average of 50 percent lower production of an immune chemical that targets the virus compared to the surviving COVID-19 patients.
3. Investigators found no evidence implicating a secondary bacterial infection as the cause of the deaths, though they said this may be because critically ill patients were frequently given antibiotics.
4. "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," Imran Sulaiman, MD, PhD, study lead author and adjunct professor in the department of medicine at NYU Langone Health, said in an Aug. 31 news release.
Investigators only studied COVID-19 patients who survived the first two weeks of hospitalization, said Leopoldo Segal, MD, study senior author and associate professor for the department of medicine at NYU Langone. Bacterial infections or autoimmune reactions may play a greater role in COVID-19 mortality occurring earlier on, Dr. Segal said.