Leal, Jenine, et al. 2020. “Have clusters of COVID-19 over time been described in condos, apartments and/or hotels? What are the most commonly hypothesized mechanisms of transmission?” Alberta Health Services, COVID-19 Scientific Advisory Group. July 16, 2020.
Key Messages from the Evidence Summary:
• There is a paucity of evidence describing clusters or outbreaks of SARS-CoV-2 infection in condos, apartments and hotels. Available studies and media reports are summarized below.
• Epidemiological investigations of multi-residential building and hotel outbreaks in the primary literature and reports in the media suggest droplet and contact with contaminated fomites as the likely source of transmission. One media report explored the role of plumbing wastewater systems as a source of respiratory exposure to SARS-CoV-2.
• Based on preliminary investigations of the Hong Mei House in Hong Kong, as reported in the media, investigators suspect a bathroom pipe that appeared to be altered with self-refitting exhaust pipes. The report suggests this contributed to transmission of SAR-CoV-2 from one resident to another, 10 floors below the index patient. An epidemiological analysis coupled with environmental study of this cluster has not been reported in the peer-reviewed academic literature or otherwise. Therefore, although mechanistically possible to transmit viral particles via plumbing systems, uncertainty remains on the contribution to transmission in indoor spaces, particularly hotels and multi-residential buildings.
• Built environments serve as potential transmission vectors for the spread of COVID-19 by inducing close interactions with individuals, by containing fomites and through viral exchange and transfer through the air or other systems (Dietz et al., 2020). Based on this rapid brief, the past review on HVAC systems, and the fact that humans spend >90% of their daily lives inside the built environment, “it is crucial to understand the potential transmission dynamics of COVID-19 within built environments, the human behavior spatial dynamics and building operational factors that may promote or mitigate the spread of COVID-19” (Dietz et al., 2020).
NOTES:
Date question received by advisory group: July 8, 2020
Date of first assessment: July 16, 2020