Architectural design and building-level infections during the early stage of COVID-19: A study of 2597 public housing buildings in Hong Kong

Abstract

Densely populated urban environments are at risk of significant economic and public health repercussions during infectious disease epidemics. Implementing stay-at-home orders became a recognized strategy in the recent pandemic. But reports of intra-building transmission and other unforeseen outcomes make it necessary to review the dynamics of such interventions. Our previous study conducted during the 5th wave of the COVID-19 pandemic in Hong Kong, characterized by the Omicron variant, highlighted the role of architectural design as a possible contributor to building-level infection. The study reported here investigates the association between architectural design, intra-building total infections (Infection_1), and consecutive infections (Infection_2) during the early stages of the pandemic. We analyzed data from the 1st to 4th waves of the pandemic, focusing on public housing units due to their homogeneity of architectural form. The study population resided in n = 2597 public housing buildings for which we obtained information about Infection_1 and Infection_2. Spatial analysis showed a marginal clustering pattern with Moran's I ranged from 0.07 to 0.16, and 0.06 to 0.13 respectively for Infection_1 and Infection_2 in intra-building infection distribution. Geographically Weighted Poisson regression (GWPR) indicated that certain architectural designs, such as ``8&L'' shape buildings were associated with significantly higher intra-building infections (IRR, 1.32; 95 % CI, 1.16–1.67 for infection_1 and IRR, 1.37, 95 % CI, 1.08–1.73 for Infection_2), I shape building increased the infection number by 43 % (IRR, 1.43; 95 % CI, 1.21–1.69 for infection_1) and 63 % (IRR, 1.63; 95 % CI, 1.31–2.02 for infection_2) in comparison with Non-standard building shape. Additionally, factors including building geometry, drainage systems, apartment size, floors, and floorplan area were also identified as significant contributors to intra-building infections. The study confirms the likely importance of architectural design in epidemic dynamics and lends weight to the argument for regarding high-rise public housing design as an important factor to create a pandemic-resilient public healthcare system. It also provides evidence consistent with the hypothesis that certain building types make it more likely that infections may spread within residential environments. This becomes an important consideration when considering the efficacy of lockdowns during an epidemic.