Uncovering Construction Site–Specific Transmission Patterns of COVID-19: A Spatiotemporal Connectivity Analysis in Hong Kong

To adapt to the prolonged pandemic, the construction industry, which has a high vulnerability to coronavirus disease 2019 (COVID-19) infection, has sought more sector-specific and individual-level nonpharmaceutical interventions (NPIs). Understanding infection transmission patterns can determine what, when, and how NPIs should be implemented. This study examined infection transmission proceeding from construction sites using spatiotemporal analysis with COVID-19 case cluster data from construction sites in Hong Kong. The study revealed that COVID-19 transmission diffuses from the workplace to residential neighborhoods where infected construction workers live but not to the surroundings of infected construction sites. The average number of offspring cases infected by each seed case in the first to fifth transmission generations were 7.8, 26.1, 10.6, 3.6, and 1.3, respectively. Around 18% of cases were responsible for 79.6% of all COVID-19 transmission, driven mainly by workplace and household settings. The study found that closing a workplace within two working days after a primary case is identified can help reduce the attack rate by 5.33%. Encouraging household members of infected construction workers to follow quarantines can reduce offspring cases by 15.84% on average. A priori identification of superspreaders can help remove half of COVID-19 cases. [ FROM AUTHOR]

Post pandemic fatigue: what are effective strategies?

Recurrent updates in non-pharmaceutical interventions (NPIs) aim to control successive waves of the coronavirus disease 2019 (COVID-19) but are often met with low adherence by the public. This study evaluated the effectiveness of gathering restrictions and quarantine policies based on a modified Susceptible-Exposed-Infectious-Hospitalized-Recovered (SEIHR) model by incorporating cross-boundary travellers with or without quarantine to study the transmission dynamics of COVID-19 with data spanning a nine-month period during 2020 in Hong Kong. The asymptotic stability of equilibria reveals that the model exhibits the phenomenon of backward bifurcation, which in this study is a co-existence between a stable disease-free equilibrium (DFE) and an endemic equilibrium (EE). Even if the basic reproduction number ([Formula: see text]) is less than unity, this disease cannot be eliminated. The effect of each parameter on the overall dynamics was assessed using Partial Rank Correlation Coefficients (PRCCs). Transmission rates (i.e., [Formula: see text] and [Formula: see text]), effective contact ratio [Formula: see text] between symptomatic individuals and quarantined people, and transfer rate [Formula: see text] related to infection during quarantine were identified to be the most sensitive parameters. The effective contact ratios between the infectors and susceptible individuals in late July were found to be over twice as high as that in March of 2020, reflecting pandemic fatigue and the potential existence of infection during quarantine.

Photovoltaic rooftop's contribution to improve building-level energy resilience during COVID-19 work-from-home arrangement.

The COVID-19 pandemic has introduced opportunities for more research in resilience as globally cities experienced lock-down, causing change to conventional energy consumption pattern especially in the residential sector. This study aims to quantify the increased energy demand during work-from-home arrangement, using high-rise public residential buildings in Hong Kong, where its government announced work-from-home arrangement four times in 2020. Building energy modellings were conducted to compare the total energy demand of residential units during normal and work-from-home arrangements, followed by validation against peer models and empirical data. A 9% residential energy demand increase was demonstrated, hence additional energy supply became desirable for the sake of resilience. This study assesses the possibility to leverage photovoltaic rooftop to supplement the increased energy demand. The photovoltaics' potential contribution was estimated by solar energy simulation and evaluated in terms of the capability to utilize its generation output to supplement the additional energy demand. During the four work-from-home periods, it was shown that a photovoltaic system could have supplemented 6.8% - 11% of the increased energy demand, mainly subject to the air-conditioning operation and solar generation. These findings are valuable to safeguard energy resilience in upcoming grid planning and operation.