ABSTRACT
The spread of infectious diseases is a spatial process, including Coronavirus disease 2019 (COVID-19). Cluster infections of COVID-19 have arisen globally in various urban spaces, implying that tracking the spread necessitates a spatial approach to understanding the dynamics of the disease. In this study, we employ an online survey in the Seoul metropolitan area in South Korea to examine changes in the use of urban spaces and factors that affect individual's choice in using urban spaces in the COVID-19 era. We classify various urban spaces into three activity types according to the previous studies: spaces for mandatory activities, maintenance activities, and discretionary activities. The results show that every type of urban space is visited less than before the COVID-19 outbreak. Factors involved in the use of spaces for mandatory activities include the preference for offline consumption, gender, and risk perception of COVID-19. In the case of non-mandatory activity spaces, factors that commonly influence the use of the spaces are compliance with social distancing regulations, preference for offline consumption, refraining from outdoor activities, risk perception of COVID-19, and perceived safety in the city concerning COVID-19. The present study is significant as it identified not only different factors affecting the choice of mandatory and non-mandatory activity spaces but also distinctive variables determining the choice of urban spaces for maintenance activity and discretionary activity. From the analysis, this study draws policy implications to effectively prevent and control infectious disease in the context of urban spaces. © 2021 SPSD Press from, SPSD Press, Kanazawa. All Rights Reserved.
ABSTRACT
Background: As only few studies have analyzed viral kinetics between the incubation and symptomatic periods of COVID-19 patients, we investigated the viral kinetics and compared viral loads between patients with mild and severe COVID-19. Methods: We determined the viral kinetics of 10 patients diagnosed with COVID-19 at Chosun University Hospital. Six patients were classified into the “mild” group and 4 into the “severe” group according to supplemental oxygen use during admission. Samples were collected via nasopharyngeal swabs and sputum specimens. SARS-CoV-2 was detected using real-time reverse transcription-polymerase chain reaction (RT-PCR). Chest radiograph scores during hospitalization were obtained Results: Ct values of the upper respiratory tract specimens were low during the early stages after symptom onset but gradually increased over time in both groups. The severe group had lower Ct values than the mild group. The Ct values of the RdRP and E genes on day 6 after symptom onset were significantly lower in the severe group than in the mild group (p < 0.05). Three of 6 patients had positive results on RT-PCR even before symptom onset;2 of them had the lowest Ct values. The chest radiograph scores were higher in the severe group than in the mild group, and the score in the severe group was the highest at approximately 3 weeks after symptom onset. Ct values when the RdRP gene and E gene were targeted to detect SARS-CoV-2 on the basis of the days after symptom onset in all the patients Conclusion: Viral load and chest radiograph scores were significantly different between the severe and mild groups of COVID-19 patients. (Figure Presented).