Georgios Kitsios, MD, PhD

The sickest patients with COVID-19 require life support on a ventilator to help their breathing while their immune system fights off the virus. About half of COVID-19 patients who end up on a ventilator do not survive, and even those who survive suffer from long-lasting consequences. Investigators to date have focused on how the SARS-CoV-2 virus is cleared from the lungs, and whether an overtly active immune system can at times cause more damage than benefit. However, about 50% of COVID-19 patients on ventilators develop a serious, life-threatening infection, called ventilator-associated pneumonia (VAP), caused by organisms other than SARS-CoV-2. We will investigate how the virus and the immune system interact with microbes in the ventilated lungs of sick patients with COVID-19. Our goal is to define targets for more timely therapeutic and preventive interventions for VAP in vulnerable patients with COVID-19 and similar viral illnesses in future epidemics.

Update:

We enrolled 112 patients with severe COVID-19 who were on ventilators in three hospitals. So far, we have identified three clusters of microbes in the lungs of patients. Patients with fewer different types of bacteria tended to have higher levels of lung inflammation and worse outcomes, such as longer times on ventilators and lower survival rates. Interestingly, we found that certain bacteria like Klebsiella were associated with higher lung inflammation, while some oral bacteria, such as Streptococcus and Rothia, were linked to potential lung injury. On the other hand, Prevotella, a common lung bacterium, was inversely related to inflammation. These results suggest that the types of bacteria in the lungs can influence the level of inflammation and potentially affect patient outcomes.