ABSTRACT
With the outbreak of the novel coronavirus pneumonia (COVID-19), urban traffic control is an important measure to block the spread and control the development of the epidemic. In this study, to elucidate the blocking effects of different traffic control measures on the transmission of COVID-19 within city territories, the four administrative cities of Jingzhou, Xiaogan, Jingmen, and Shijiazhuang were selected as the study areas. The situation of the epidemic before and after the implementation of three typical traffic control measures-road closure, passenger traffic stoppage, and community population flow control-was analyzed. Based on the classical dynamics theory of infectious diseases, an optimized epidemic transmission susceptible, infectious, removed, exposed (SEIR) model was established, considering the infectivity of the exposed, population migration, and population flow in urban communities. Thereafter, the model was used to study the blocking effects based on whether traffic control measures were implemented in each city and the various traffic control measures on the development of the epidemic. The results indicate that the daily incidence rate of each city is related to the immigration index of approximately 14 days ago;the traffic control measures adopted by each city are also highly effective in blocking the spread of the epidemic. Compared with no traffic control measures, the peak numbers of infected persons in Jingzhou, Xiaogan, Jingmen, and Shijiazhuang decreased by 61.29%, 53.71%, 66.16%, and 66.33%, respectively. The blocking effects of the three control measures exhibit a few differences. The blocking effect of road closure measures is the most prominent;the numbers of latent and infected persons can be reduced by 40.54%-70.88% and 49.11%-64.34%, respectively, using different implementation nodes. Furthermore, a timely and comprehensive implementation of the three traffic control measures can effectively block the spread of the epidemic and control the development of the epidemic in cities. This improved SEIR model, which considers the characteristics of the incubation period, can accurately predict the development trends of the epidemic, thus serving as a technical reference for the formulation of urban traffic control plans over the duration of the epidemic. © 2022, Editorial Department of China Journal of Highway and Transport. All right reserved.
ABSTRACT
The outbreak of coronavirus disease-19 (COVID-19) caused by novel coronavirus (severe acute respiratory syndrome coronavirus-2, SARS-CoV-2) has posed a serious threat to public health. Virus particles of SARS-CoV-2 are composed of outer envelopes and inner nucleocapsids. The nonstructural and structural proteins encoded by the genome play an important role in the whole life cycle of their adsorption, penetration, uncoating, synthesis of nucleic acids and proteins, assembly and liberation. Antiviral drugs can be developed to target the virus itself or key host molecules for virus infection. So far, antibody drugs targeting spike glycoprotein S and small molecule drugs targeting RNA polymerase have shown antiviral effects. They are currently more promising candidate drugs. However, their efficacy still needs to be proved by further clinical trials, and miracle antiviral drugs have not yet appeared. Considering the virus and host targets, the combination therapy of multi-targets and multidrugs, may achieve better therapeutic effect. In this paper, the structure and life cycle of SARS-CoV-2, the research progress in potential targets and drugs were reviewed to provide useful information for the development of anti-SARS-CoV-2 drugs.
ABSTRACT
As the coronavirus disease of 2019 (COVID-19) is spreading around the world, the number of confirmed cases and deaths continues to rise rapidly. However, there are still no specific drugs for its treatment. Chloroquine, a classic medication used for malaria and autoimmune diseases, has attracted public attention due to its potential efficacy against COVID-19. Hydroxychloroquine, the derivative of chloroquine, has similar potency but much less toxicity relative to chloroquine. Hydroxychloroquine has been listed as one of the four candidate drugs for treatment of COVID-19 by the World Health Organization and included in the sixth and seventh editions of the COVID-19 Treatment Plan of the National Health Commission of the People's Republic of China. Nevertheless, the clinical efficacy of chloroquine and hydroxychloroquine against COVID-19 is still controversial and the clinical data to date are not sufficient to support chloroquine and hydroxychloroquine as the recommended drugs for treating COVID-19. In order to better understand the drug treatment of COVID-19, here we summarized the current medications used for this new pandemic disease, focusing on the efficacy of hydroxychloroquine in clinical trials. In addition, we analyzed the potential mechanisms of the opposite outcomes of hydroxychloroquine in clinical trials. Finally, we discussed the therapeutic effect of anisodamine and antiviral agents remdesivir and psychological intervention in treatment of COVID-19. It is believed that these discussions will provide important reference for the rationalization of COVID-19 therapies. © 2020 Chinese Journal of Pharmacology and Toxicology. All rights reserved.