Detection of SARS-CoV-2 in the air from hospitals and closed rooms occupied by COVID-19 patients

To understand air transmission characteristics of SARS-CoV-2 and risks for health care personnel and visitors to hospitals, we analyzed air samples collected from various enclosures in hospitals at Hyderabad and Mohali and performed closed room experiments with COVID-19 positive individuals. We collected 64 air samples from COVID and non-COVID areas of various hospitals and 17 samples from closed rooms occupied by COVID patients. 4 samples from COVID care areas were positive for SARS-CoV-2 with no obvious predilection towards ICU/non-ICU areas in the hospital samples. In the closed room experiments, where one or more COVID-19 patients spent a short duration of time, one sample - collected immediately after the departure of three symptomatic patients from the room - was positive. Our results indicate that the chance of picking up SARS-CoV-2 in the air is directly related to a number of COVID positive cases in the room, their symptomatic status, and the duration of exposure and that the demarcation of hospital areas into COVID and non-COVID areas is a successful strategy to prevent cross infections. In neutral environmental conditions, the virus does not seem to spread farther away from the patients, especially if they are asymptomatic, giving an objective evidence for the effectiveness of physical distancing in curbing the spread of the epidemic.