SARS‐CoV‐2 indoor environment contamination with epidemiological and experimental investigations

SARS- CoV- 2 has been detected both in air and on surfaces, but questions remain about the patient-specific and environmental factors affecting virus transmission. Additionally, more detailed information on viral sampling of the air is needed. This prospective cohort study (N= 56) presents results from 258 air and 252 surface samples from the surroundings of 23 hospitalized and eight home- treated COVID-19 index patients between July 2020 and March 2021 and compares the results between the measured environments and patient factors. Additionally, epidemiological and experimental investigations were performed. The proportions of qRT- PCR- positiveair (10.7% hospital/17.6% homes) and surface samples (8.8%/12.9%) showed statisti-cal similarity in hospital and homes. Significant SARS- CoV- 2 air contamination was observed in a large (655.25 m3) mechanically ventilated (1.67 air changes per hour, 32.4– 421 L/s/patient) patient hall even with only two patients present. All positive air samples were obtained in the absence of aerosol- generating procedures. In four cases, positive environmental samples were detected after the patients had devel-oped a neutralizing IgG response. SARS- CoV- 2 RNA was detected in the following particle sizes: 0.65– 4.7 μm , 7. 0– 12.0 μm, >10μm, and