Probable Evidence of Fecal Aerosol Transmission of SARS-CoV-2 in a High-Rise Building.

BACKGROUND

The role of fecal aerosols in the transmission of severe acute respiratory syndrome coronavirus 2 has been suspected.

OBJECTIVE

To investigate the temporal and spatial distributions of 3 infected families in a high-rise apartment building and examine the associated environmental variables to verify the role of fecal aerosols.

DESIGN

Epidemiologic survey and quantitative reverse transcriptase polymerase chain reaction analyses on throat swabs from the participants; 237 surface and air samples from 11 of the 83 flats in the building, public areas, and building drainage systems; and tracer gas released into bathrooms as a surrogate for virus-laden aerosols in the drainage system.

SETTING

A high-rise apartment building in Guangzhou, China.

PARTICIPANTS

9 infected patients, 193 other residents of the building, and 24 members of the building's management staff.

MEASUREMENTS: Locations of infected flats and positive environmental samples, and spread of virus-laden aerosols.

RESULTS

9 infected patients in 3 families were identified. The first family had a history of travel to the coronavirus disease 2019 (COVID-19) epicenter Wuhan, whereas the other 2 families had no travel history and a later onset of symptoms. No evidence was found for transmission via the elevator or elsewhere. The families lived in 3 vertically aligned flats connected by drainage pipes in the master bathrooms. Both the observed infections and the locations of positive environmental samples are consistent with the vertical spread of virus-laden aerosols via these stacks and vents.

LIMITATION: Inability to determine whether the water seals were dried out in the flats of the infected families.

CONCLUSION

On the basis of circumstantial evidence, fecal aerosol transmission may have caused the community outbreak of COVID-19 in this high-rise building.

PRIMARY FUNDING SOURCE: Key-Area Research and Development Program of Guangdong Province and the Research Grants Council of Hong Kong.