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

Ann Intern Med. 2020 Dec 15;173(12):974-980. doi: 10.7326/M20-0928. Epub 2020 Sep 1.


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.

Publication types

  • Multicenter Study

MeSH terms

  • Aerosols / adverse effects*
  • COVID-19 / epidemiology
  • COVID-19 / transmission*
  • China / epidemiology
  • Disease Transmission, Infectious / statistics & numerical data*
  • Feces / virology
  • Humans
  • RNA, Viral / analysis*
  • Retrospective Studies
  • SARS-CoV-2 / genetics*


  • Aerosols
  • RNA, Viral