scholarly journals The spatial transmission of SARS-CoV-2 in China under the prevention and control measures at the early outbreak

2021 ◽  
Vol 79 (1) ◽  
Author(s):  
Jianli Liu ◽  
Yuan Zhou ◽  
Chuanyu Ye ◽  
Guangming Zhang ◽  
Feng Zhang ◽  
...  
Keyword(s):  
Basic Reproduction Number ◽  
Prevention And Control ◽  
Reproduction Number ◽  
Early Stage ◽  
Chinese Mainland ◽  
Hubei Province ◽  
Control Measures ◽  
Provincial Level ◽  
Prevention And Control Measures ◽  
And Control

Abstract Background Since severe acute respiratory syndrome coronavirus, 2 (SARS-CoV-2) was firstly reported in Wuhan City, China in December 2019, Novel Coronavirus Disease 2019 (COVID-19) that is caused by SARS-CoV-2 is predominantly spread from person-to-person on worldwide scales. Now, COVID-19 is a non-traditional and major public health issue the world is facing, and the outbreak is a global pandemic. The strict prevention and control measures have mitigated the spread of SARS-CoV-2 and shown positive changes with important progress in China. But prevention and control tasks remain arduous for the world. The objective of this study is to discuss the difference of spatial transmission characteristics of COVID-19 in China at the early outbreak stage with resolute efforts. Simultaneously, the COVID-19 trend of China at the early time was described from the statistical perspective using a mathematical model to evaluate the effectiveness of the prevention and control measures. Methods In this study, the accumulated number of confirmed cases publicly reported by the National Health Committee of the People’s Republic of China (CNHC) from January 20 to February 11, 2020, were grouped into three partly overlapping regions: Chinese mainland including Hubei province, Hubei province alone, and the other 30 provincial-level regions on Chinese mainland excluding Hubei province, respectively. A generalized-growth model (GGM) was used to estimate the basic reproduction number to evaluate the transmissibility in different spatial locations. The prevention and control of COVID-19 in the early stage were analyzed based on the number of new cases of confirmed infections daily reported. Results Results indicated that the accumulated number of confirmed cases reported from January 20 to February 11, 2020, is well described by the GGM model with a larger correlation coefficient than 0.99. When the accumulated number of confirmed cases is well fitted by an exponential function, the basic reproduction number of COVID-19 of the 31 provincial-level regions on the Chinese mainland, Hubei province, and the other 30 provincial-level regions on the Chinese mainland excluding Hubei province, is 2.68, 6.46 and 2.18, respectively. The consecutive decline of the new confirmed cases indicated that the prevention and control measures taken by the Chinese government have contained the spread of SARS-CoV-2 in a short period. Conclusions The estimated basic reproduction number thorough GGM model can reflect the spatial difference of SARS-CoV-2 transmission in China at the early stage. The strict prevention and control measures of SARS-CoV-2 taken at the early outbreak can effectively reduce the new confirmed cases outside Hubei and have mitigated the spread and yielded positive results since February 2, 2020. The research results indicated that the outbreak of COVID-19 in China was sustaining localized at the early outbreak stage and has been gradually curbed by China’s resolute efforts.

scholarly journals A deterministic epidemic model for the emergence of COVID-19 in China

2020 ◽  
Author(s):  
Meng Wang ◽  
Jingtao Qi
Keyword(s):  
Prevention And Control ◽  
Reproduction Number ◽  
Chinese Mainland ◽  
Hubei Province ◽  
Control Measures ◽  
The Novel ◽  
Health Authorities ◽  
Prevention And Control Measures ◽  
Novel Coronavirus ◽  
And Control

AbstractCoronavirus disease (COVID-19) broke out in Wuhan, Hubei province, China, in December 2019 and soon after Chinese health authorities took unprecedented prevention and control measures to curb the spreading of the novel coronavirus-related pneumonia. We develop a mathematical model based on daily updates of reported cases to study the evolution of the epidemic. With the model, on 95% confidence level, we estimate the basic reproduction number, R0 = 2.82 ± 0.11, time between March 19 and March 21 when the effective reproduction number becoming less than one, the epidemic ending after April 2 and the total number of confirmed cases approaching 14408 ± 429 on the Chinese mainland excluding Hubei province.

scholarly journals Heterogeneity and effectiveness analysis of COVID-19 prevention and control in major cities in China through time-varying reproduction number estimation

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Qing Cheng ◽  
Zeyi Liu ◽  
Guangquan Cheng ◽  
Jincai Huang
Keyword(s):  
Prevention And Control ◽  
Large Scale ◽  
Reproduction Number ◽  
Correlation Method ◽  
Control Measures ◽  
Time Varying ◽  
Short Period ◽  
Significant Difference ◽  
Prevention And Control Measures ◽  
And Control

AbstractBeginning on December 31, 2019, the large-scale novel coronavirus disease 2019 (COVID-19) emerged in China. Tracking and analysing the heterogeneity and effectiveness of cities’ prevention and control of the COVID-19 epidemic is essential to design and adjust epidemic prevention and control measures. The number of newly confirmed cases in 25 of China’s most-affected cities for the COVID-19 epidemic from January 11 to February 10 was collected. The heterogeneity and effectiveness of these 25 cities’ prevention and control measures for COVID-19 were analysed by using an estimated time-varying reproduction number method and a serial correlation method. The results showed that the effective reproduction number (R) in 25 cities showed a downward trend overall, but there was a significant difference in the R change trends among cities, indicating that there was heterogeneity in the spread and control of COVID-19 in cities. Moreover, the COVID-19 control in 21 of 25 cities was effective, and the risk of infection decreased because their R had dropped below 1 by February 10, 2020. In contrast, the cities of Wuhan, Tianmen, Ezhou and Enshi still had difficulty effectively controlling the COVID-19 epidemic in a short period of time because their R was greater than 1.

scholarly journals Modeling and Reviewing Study to the COVID-19 Epidemic in PR China

2020 ◽  
Author(s):  
Mingzhao Wang ◽  
Juanying Xie ◽  
Shengquan Xu
Keyword(s):  
Prevention And Control ◽  
Hubei Province ◽  
Control Measures ◽  
Transmission Model ◽  
Chinese Government ◽  
Wuhan City ◽  
The Mainland Of China ◽  
Prevention And Control Measures ◽  
And Control ◽  
Model Fits

Abstract Background: COVID-19 epidemic has been widely spread all over the world. During it appears in China, Chinese government quickly put forward and implement prevention and control measures to keep its spread within limits. This study aims to investigate the impacts of the prevention and control measures in controlling COVID-19 epidemic in China, so as to give a clue to control its spread in the world. Methods: We establish a two-stage dynamics transmission model with "lockdown of Wuhan city" as the time line. The first stage is the SEIR derived model that considers the contagious of the exposed. It simulates the COVID-19 epidemic in Hubei Province before "lockdown of Wuhan city". The second stage is a novel transmission dynamics model named SEIRQH. It takes into account the influence on the COVID-19 epidemic from the series of measures such as travel restriction, contact tracing, centralized treatment, the asymptomatic infected patients, hospitalized patients and so on. It simulates the COVID-19 epidemic in China after "lockdown of Wuhan city". The least square method is used to estimate the parameters of SEIR derived model and the proposed SEIRQH model based on the collected epidemic data of COVID-19 from Hubei Province and the mainland of China. Results: The SEIR derived model fits the actual data in Hubei Province before "lockdown of Wuhan city". The basic reproduction number of COVID-19 epidemic in Hubei Province is 3.2035 before "lockdown of Wuhan city". The SEIRQH model fits the number of the hospitalized persons of COVID-19 in Hubei Province and the mainland of China perfectly. The control reproductive number are 0.11428 and 0.09796 in Hubei Province and the mainland of China, respectively. The prevention and control measures taken by Chinese government play the significant role against the COVID-19 spread in China. Conclusions: Our two-stage dynamics transmission model simulates the COVID-19 in China, especially our SEIRQH model fits the actual data very well. The prevention and control measures implemented by Chinese government are effective in preventing the wide spread of COVID-19 epidemic in China. These measures give the reference to World Health Organization and other countries in controlling COVID-19 epidemic.

scholarly journals Beware of asymptomatic transmission: Study on 2019-nCoV prevention and control measures based on extended SEIR model

2020 ◽  
Author(s):  
Peng Shao ◽  
Yingji Shan
Keyword(s):  
Prevention And Control ◽  
Early Stage ◽  
Control Measures ◽  
World Health ◽  
Epidemic Spread ◽  
Prevention And Control Measures ◽  
Health Organization ◽  
Almost All ◽  
And Control ◽  
The Impact

SummaryBackgroundThe 2019 new coronavirus, “2019-nCoV”, was discovered from Wuhan Viral Pneumonia cases in December 2019, and was named by the World Health Organization on January 12, 2020. In the early stage, people knows little about the 2019-nCoV virus was not clear, and the spread period was encountering China’s annual spring migration, which made the epidemic spread rapidly from Wuhan to almost all provinces in China.MethodsThis study builds a SEIRD model that considers the movement of people across regions, revealing the effects of three measures on controlling the spread of the epidemic.Based on MATLAB R2017a, computational experiments were performed to simulate the epidemic prevention and control measures.FindingsThe research results show that current prevention and control measures in China are very necessary. This study further validates the concerns of international and domestic experts regarding asymptomatic transmission (E-status).InterpretationThe results of this study are applicable to explore the impact of the implementation of relevant measures on the prevention and control of epidemic spread, and to identify key individuals that may exist during the spread of the epidemic.

scholarly journals Modeling and Reviewing Study to the COVID-19 Epidemic in PR China

2020 ◽  
Author(s):  
Mingzhao Wang ◽  
Juanying Xie ◽  
Shengquan Xu
Keyword(s):  
Prevention And Control ◽  
Hubei Province ◽  
Control Measures ◽  
Transmission Model ◽  
Chinese Government ◽  
Wuhan City ◽  
The Mainland Of China ◽  
Prevention And Control Measures ◽  
And Control ◽  
Model Fits

Abstract Background: COVID-19 epidemic has been widely spread all over the world. During it appears in China, Chinese government quickly put forward and implement prevention and control measures to keep its spread within limits. This study aims to investigate the impacts of the prevention and control measures in controlling COVID-19 epidemic in China, so as to give a clue to control its spread in the world. Methods: We establish a two-stage dynamics transmission model with "lockdown of Wuhan city" as the time line. The first stage is the SEIR derived model that considers the contagious of the exposed. It simulates the COVID-19 epidemic in Hubei Province before "lockdown of Wuhan city". The second stage is a novel transmission dynamics model named SEIRQH. It takes into account the influence on the COVID-19 epidemic from the series of measures such as travel restriction, contact tracing, centralized treatment, the asymptomatic infected patients, hospitalized patients and so on. It simulates the COVID-19 epidemic in China after "lockdown of Wuhan city". The least square method is used to estimate the parameters of SEIR derived model and the proposed SEIRQH model based on the collected epidemic data of COVID-19 from Hubei Province and the mainland of China. Results: The SEIR derived model fits the actual data in Hubei province before "lockdown of Wuhan city". The basic reproduction number of COVID-19 epidemic in Hubei Province is 3.2035 before "lockdown of Wuhan city". The SEIRQH model fits the number of the hospitalized persons of COVID-19 in Hubei Province and the mainland of China perfectly. The control reproductive number are 0.11428 and 0.09796 in Hubei Province and the mainland of China, respectively. The prevention and control measures taken by Chinese government play the significant role against the COVID-19 spread in China. Conclusions: Our two-stage dynamics transmission model simulates the COVID-19 in China, especially our SEIRQH model fits the actual data very well. The prevention and control measures implemented by Chinese government are effective in preventing the wide spread of COVID-19 epidemic in China. These measures give the reference to World Health Organization and other countries in controlling COVID-19 epidemic.

Knowledge and Awareness of Dengue Fever

2018 ◽  
pp. 219-222
Author(s):  
Y. Arockia Suganthi ◽  
Chitra K. ◽  
J. Magelin Mary
Keyword(s):  
Dengue Fever ◽  
Prevention And Control ◽  
Control Measures ◽  
Infection Transmission ◽  
Standard Guideline ◽  
The World ◽  
Different Types ◽  
Prevention And Control Measures ◽  
Dengue Prevention ◽  
And Control

Dengue fever is a painful mosquito-borne infection caused by different types of virus in various localities of the world. There is no particular medicine or vaccine to treat person suffering from dengue fever. Dengue viruses are transmitted by the bite of female Aedes (Ae) mosquitoes. Dengue fever viruses are mainly transmitted by Aedes which can be active in tropical or subtropical climates. Aedes Aegypti is the key step to avoid infection transmission to save millions of people in all over the world. This paper provides a standard guideline in the planning of dengue prevention and control measures. At the same time gives the priorities including clinical management and hospitalized dengue patients have to address essentially.

An evaluation model of 2019-nCoV prevention effectiveness based on immigration data in China (Preprint)

2020 ◽  
Author(s):  
Qiangsheng Huang
Keyword(s):  
Prevention And Control ◽  
Time Window ◽  
Evaluation Model ◽  
Control Measures ◽  
Related Data ◽  
The Face ◽  
Prevention And Control Measures ◽  
And Control ◽  
Best Fit

BACKGROUND As of the end of February 2020, 2019-nCoV is currently well controlled in China. However, the virus is now spreading globally. OBJECTIVE This study aimed to evaluate the effectiveness of outbreak prevention and control measures in a region. METHODS A model is built for find the best fit for two sets of data (the number of daily new diagnosed, and the risk value of incoming immigration population). The parameters (offset and time window) in the model can be used as the evaluation of effectiveness of outbreak prevention and control. RESULTS Through study, it is found that the parameter offset and time window in the model can accurately reflect the prevention effectiveness. Some related data and public news confirm this result. And this method has advantages over the method using R0 in two aspects. CONCLUSIONS If the epidemic situation is well controlled, the virus is not terrible. Now the daily new diagnosed patients in most regions of China is quickly reduced to zero or close to zero. Chinese can do a good job in the face of huge epidemic pressure. Therefore, if other countries can do well in prevention and control, the epidemic in those places can also pass quickly.

scholarly journals Analysis and prediction of the coronavirus disease epidemic in China based on an individual-based model

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Zuiyuan Guo ◽  
Dan Xiao
Keyword(s):  
Reproduction Number ◽  
Control Measures ◽  
Cumulative Number ◽  
Individual Based Model ◽  
Whole Process ◽  
Coordinate Descent Algorithm ◽  
Initial Stage ◽  
The Government ◽  
Prevention And Control Measures ◽  
And Control

AbstractWe established a stochastic individual-based model and simulated the whole process of occurrence, development, and control of the coronavirus disease epidemic and the infectors and patients leaving Hubei Province before the traffic was closed in China. Additionally, the basic reproduction number (R0) and number of infectors and patients who left Hubei were estimated using the coordinate descent algorithm. The median R0 at the initial stage of the epidemic was 4.97 (95% confidence interval [CI] 4.82–5.17). Before the traffic lockdown was implemented in Hubei, 2000 (95% CI 1982–2030) infectors and patients had left Hubei and traveled throughout the country. The model estimated that if the government had taken prevention and control measures 1 day later, the cumulative number of laboratory-confirmed patients in the whole country would have increased by 32.1%. If the lockdown of Hubei was imposed 1 day in advance, the cumulative number of laboratory-confirmed patients in other provinces would have decreased by 7.7%. The stochastic model could fit the officially issued data well and simulate the evolution process of the epidemic. The intervention measurements nationwide have effectively curbed the human-to-human transmission of severe acute respiratory syndrome coronavirus 2.

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