Viable SARS CoV 2 in the air of a hospital room with COVID 19 patients
Background There currently is substantial controversy about the role played by SARS CoV 2 in aerosols in disease transmission, due in part to detections of viral RNA but failures to isolate viable virus from clinically generated aerosols. Methods Air samples were collected in the room of two COVID 19 patients, one of whom had an active respiratory infection with a nasopharyngeal (NP) swab positive for SARS CoV 2 by RT qPCR. By using VIVAS air samplers that operate on a gentle water vapor condensation principle, material was collected from room air and subjected to RT qPCR and virus culture. The genomes of the SARS CoV 2 collected from the air and of virus isolated in cell culture from air sampling and from a NP swab from a newly admitted patient in the room were sequenced. Findings Viable virus was isolated from air samples collected 2 to 4.8m away from the patients. The genome sequence of the SARS CoV 2 strain isolated from the material collected by the air samplers was identical to that isolated from the NP swab from the patient with an active infection. Estimates of viable viral concentrations ranged from 6 to 74 TCID50 units/L of air. Interpretation Patients with respiratory manifestations of COVID 19 produce aerosols in the absence of aerosol generating procedures that contain viable SARS CoV 2, and these aerosols may serve as a source of transmission of the virus.
medRxiv