scholarly journals Risk Assessment of Novel Coronavirus COVID-19 Outbreaks Outside China

2020 ◽  
Author(s):  
Péter Boldog ◽  
Tamás Tekeli ◽  
Zsolt Vizi ◽  
Attila Dénes ◽  
Ferenc A. Bartha ◽  
...  
Keyword(s):  
Control Measure ◽  
Mainland China ◽  
Destination Country ◽  
Control Measures ◽  
Cumulative Number ◽  
Travel Restrictions ◽  
Imported Cases ◽  
Major Outbreak ◽  
Novel Coronavirus ◽  
Local Reproduction

AbstractWe developed a computational tool to assess the risks of novel coronavirus outbreaks outside of China. We estimate the dependence of the risk of a major outbreak in a country from imported cases on key parameters such as: (i) the evolution of the cumulative number of cases in mainland China outside the closed areas; (ii) the connectivity of the destination country with China, including baseline travel frequencies, the effect of travel restrictions, and the efficacy of entry screening at destination; and (iii) the efficacy of control measures in the destination country (expressed by the local reproduction number Rloc). We found that in countries with low connectivity to China but with relatively high Rloc, the most beneficial control measure to reduce the risk of outbreaks is a further reduction in their importation number either by entry screening or travel restrictions. Countries with high connectivity but low Rloc benefit the most from policies that further reduce Rloc. Countries in the middle should consider a combination of such policies. Risk assessments were illustrated for selected groups of countries from America, Asia, and Europe. We investigated how their risks depend on those parameters, and how the risk is increasing in time as the number of cases in China is growing.

scholarly journals Risk Assessment of Novel Coronavirus COVID-19 Outbreaks Outside China

2020 ◽  
Vol 9 (2) ◽  
pp. 571 ◽  
Author(s):  
Péter Boldog ◽  
Tamás Tekeli ◽  
Zsolt Vizi ◽  
Attila Dénes ◽  
Ferenc A. Bartha ◽  
...  
Keyword(s):  
Control Measure ◽  
Mainland China ◽  
Destination Country ◽  
Control Measures ◽  
Cumulative Number ◽  
Travel Restrictions ◽  
Imported Cases ◽  
Major Outbreak ◽  
Novel Coronavirus ◽  
Local Reproduction

We developed a computational tool to assess the risks of novel coronavirus outbreaks outside of China. We estimate the dependence of the risk of a major outbreak in a country from imported cases on key parameters such as: (i) the evolution of the cumulative number of cases in mainland China outside the closed areas; (ii) the connectivity of the destination country with China, including baseline travel frequencies, the effect of travel restrictions, and the efficacy of entry screening at destination; and (iii) the efficacy of control measures in the destination country (expressed by the local reproduction number R loc ). We found that in countries with low connectivity to China but with relatively high R loc , the most beneficial control measure to reduce the risk of outbreaks is a further reduction in their importation number either by entry screening or travel restrictions. Countries with high connectivity but low R loc benefit the most from policies that further reduce R loc . Countries in the middle should consider a combination of such policies. Risk assessments were illustrated for selected groups of countries from America, Asia, and Europe. We investigated how their risks depend on those parameters, and how the risk is increasing in time as the number of cases in China is growing.

scholarly journals The effect of travel restrictions on the spread of the 2019 novel coronavirus (2019-nCoV) outbreak

2020 ◽  
Author(s):  
Matteo Chinazzi ◽  
Jessica T. Davis ◽  
Marco Ajelli ◽  
Corrado Gioannini ◽  
Maria Litvinova ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Mainland China ◽  
International Travel ◽  
Transmission Model ◽  
Rapid Spread ◽  
Travel Restrictions ◽  
Imported Cases ◽  
Novel Coronavirus ◽  
Disease Transmission Model ◽  
The Impact

AbstractMotivated by the rapid spread of a novel coronavirus (2019-nCoV) in Mainland China, we use a global metapopulation disease transmission model to project the impact of both domestic and international travel limitations on the national and international spread of the epidemic. The model is calibrated on the evidence of internationally imported cases before the implementation of the travel quarantine of Wuhan. By assuming a generation time of 7.5 days, the reproduction number is estimated to be 2.4 [90% CI 2.2-2.6]. The median estimate for number of cases before the travel ban implementation on January 23, 2020 is 58,956 [90% CI 40,759 - 87,471] in Wuhan and 3,491 [90% CI 1,924 - 7,360] in other locations in Mainland China. The model shows that as of January 23, most Chinese cities had already received a considerable number of infected cases, and the travel quarantine delays the overall epidemic progression by only 3 to 5 days. The travel quarantine has a more marked effect at the international scale, where we estimate the number of case importations to be reduced by 80% until the end of February. Modeling results also indicate that sustained 90% travel restrictions to and from Mainland China only modestly affect the epidemic trajectory unless combined with a 50% or higher reduction of transmission in the community.

scholarly journals Government management capacities and the containment of COVID-19: a repeated cross-sectional study across Chinese cities

BMJ Open ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. e041516
Author(s):  
Wenchao Li ◽  
Jing Li ◽  
Junjian Yi
Keyword(s):  
Outcome Measures ◽  
Cross Sectional Study ◽  
Control Measures ◽  
Secondary Outcome ◽  
Cross Sectional ◽  
Travel Restrictions ◽  
Government Management ◽  
The Government ◽  
Laws And Policies ◽  
Novel Coronavirus

ObjectivesBetter understanding of the dynamics of the COVID-19 (2019 novel coronavirus disease) pandemic to curb its spread is now a global imperative. While travel restrictions and control measures have been shown to limit the spread of the disease, the effectiveness of the enforcement of those measures should depend on the strength of the government. Whether, and how, the government plays a role in fighting the disease, however, has not been investigated. Here, we show that government management capacities are critical to the containment of the disease.SettingWe conducted a statistical analysis based on cross-city comparisons within China. China has undergone almost the entire cycle of the anticoronavirus campaign, which allows us to trace the full dynamics of the outbreak, with homogeneity in standards for statistics recording.Primary and secondary outcome measuresOutcome measures include city-specific COVID-19 case incidence and recoveries in China.ResultsThe containment of COVID-19 depends on the effectiveness of the enforcement of control measures, which in turn depends on the local government’s management capacities. Specifically, government efficiency, capacity for law enforcement, and the transparency of laws and policies significantly reduce COVID-19 prevalence and increase the likelihood of recoveries. The organisation size of the government, which is not closely related to its capacity for management, has a limited role.

scholarly journals Estimating the number of undetected COVID-19 cases among travellers from mainland China

2021 ◽  
Vol 5 ◽  
pp. 143
Author(s):  
Sangeeta Bhatia ◽  
Natsuko Imai ◽  
Gina Cuomo-Dannenburg ◽  
Marc Baguelin ◽  
Adhiratha Boonyasiri ◽  
...  
Keyword(s):  
Mainland China ◽  
Relative Sensitivity ◽  
Absolute Number ◽  
Wuhan City ◽  
The World ◽  
Travel Restrictions ◽  
Imported Cases ◽  
The Absolute ◽  
Country Specific

Background: As of August 2021, every region of the world has been affected by the COVID-19 pandemic, with more than 196,000,000 cases worldwide. Methods: We analysed COVID-19 cases among travellers from mainland China to different regions and countries, comparing the region- and country-specific rates of detected and confirmed cases per flight volume to estimate the relative sensitivity of surveillance in different regions and countries. Results: Although travel restrictions from Wuhan City and other cities across China may have reduced the absolute number of travellers to and from China, we estimated that up to 70% (95% CI: 54% - 80%) of imported cases could remain undetected relative to the sensitivity of surveillance in Singapore. The percentage of undetected imported cases rises to 75% (95% CI 66% - 82%) when comparing to the surveillance sensitivity in multiple countries. Conclusions: Our analysis shows that a large number of COVID-19 cases remain undetected across the world. These undetected cases potentially resulted in multiple chains of human-to-human transmission outside mainland China.

scholarly journals Notes from the Field: Effectiveness of Prevention and Control Measures for Imported COVID-19 in Guangming District of Shenzhen

2020 ◽  
pp. 016327872097183
Author(s):  
Xiaoliang Chen ◽  
Tieqiang Wang ◽  
Yang Zhao ◽  
Yunjie Wu ◽  
Ranran Qie ◽  
...  
Keyword(s):  
Prevention And Control ◽  
Local Community ◽  
Management Strategies ◽  
Screening Strategy ◽  
Control Measures ◽  
Imported Cases ◽  
Returning To Work ◽  
Prevention And Control Measures ◽  
Novel Coronavirus ◽  
And Control

Novel coronavirus disease 2019 (COVID-19) was present in most provinces of China after January 2020. We implemented a surveillance and screening strategy that included early detection of laboratory-confirmed COVID-19 cases and people who were exposed to the disease in Guangming District of Shenzhen. Separate targeted treatment and management strategies were applied to confirmed and suspected cases. From January 23 to March 13, 2020, we found 12 suspected cases, and 11 were confirmed as positive. Although eight of the 11 confirmed cases were family-aggregated, they were all imported cases with common exposure, which did not further cause local community transmission, and no medical staff were infected. After February 14, when the last case was confirmed, there were no newly confirmed cases for 28 consecutive days under the strict outbreak control. The targeted and whole-society involved prevention and control measures prevented the spread of the disease in a very short time and provided a strong guarantee for the orderly recovery of returning to work and social activities.

scholarly journals Modeling the Novel Coronavirus (SARS-CoV-2) Outbreak in Sicily, Italy

2020 ◽  
Vol 17 (14) ◽  
pp. 4964 ◽  
Author(s):  
Andrea Maugeri ◽  
Martina Barchitta ◽  
Sebastiano Battiato ◽  
Antonella Agodi
Keyword(s):  
Transmission Rate ◽  
Control Measures ◽  
Transmission Dynamics ◽  
The Novel ◽  
Epidemic Spread ◽  
Transmission Rates ◽  
Contact Precautions ◽  
Travel Restrictions ◽  
Novel Coronavirus ◽  
Reported Data

Italy was the first country in Europe which imposed control measures of travel restrictions, quarantine and contact precautions to tackle the epidemic spread of the novel coronavirus (SARS-CoV-2) in all its regions. While such efforts are still ongoing, uncertainties regarding SARS-CoV-2 transmissibility and ascertainment of cases make it difficult to evaluate the effectiveness of restrictions. Here, we employed a Susceptible-Exposed-Infectious-Recovered-Dead (SEIRD) model to assess SARS-CoV-2 transmission dynamics, working on the number of reported patients in intensive care unit (ICU) and deaths in Sicily (Italy), from 24 February to 13 April. Overall, we obtained a good fit between estimated and reported data, with a fraction of unreported SARS-CoV-2 cases (18.4%; 95%CI = 0–34.0%) before 10 March lockdown. Interestingly, we estimated that transmission rate in the community was reduced by 32% (95%CI = 23–42%) after the first set of restrictions, and by 80% (95%CI = 70–89%) after those adopted on 23 March. Thus, our estimates delineated the characteristics of SARS-CoV2 epidemic before restrictions taking into account unreported data. Moreover, our findings suggested that transmission rates were reduced after the adoption of control measures. However, we cannot evaluate whether part of this reduction might be attributable to other unmeasured factors, and hence further research and more accurate data are needed to understand the extent to which restrictions contributed to the epidemic control.

scholarly journals A data-driven assessment of early travel restrictions related to the spreading of the novel COVID-19 within mainland China

2020 ◽  
Author(s):  
Alberto Aleta ◽  
Qitong Hu ◽  
Jiachen Ye ◽  
Peng Ji ◽  
Yamir Moreno
Keyword(s):  
Mainland China ◽  
Behavioral Changes ◽  
The Novel ◽  
Metapopulation Model ◽  
Short Term ◽  
Effective Measure ◽  
Mobility Data ◽  
Health Authorities ◽  
Travel Restrictions ◽  
Novel Coronavirus

Two months after it was firstly reported, the novel coronavirus disease COVID-19 has already spread worldwide. However, the vast majority of reported infections have occurred in China. To assess the effect of early travel restrictions adopted by the health authorities in China, we have implemented an epidemic metapopulation model that is fed with mobility data corresponding to 2019 and 2020. This allows to compare two radically different scenarios, one with no travel restrictions and another in which mobility is reduced by a travel ban. Our findings indicate that i) travel restrictions are an effective measure in the short term, however, ii) they are ineffective when it comes to completely eliminate the disease. The latter is due to the impossibility of removing the risk of seeding the disease to other regions. Our study also highlights the importance of developing more realistic models of behavioral changes when a disease outbreak is unfolding.

scholarly journals The impact of transmission control measures during the first 50 days of the COVID-19 epidemic in China

2020 ◽  
Author(s):  
Huaiyu Tian ◽  
Yonghong Liu ◽  
Yidan Li ◽  
Chieh-Hsi Wu ◽  
Bin Chen ◽  
...  
Keyword(s):  
Emergency Response ◽  
Case Reports ◽  
Human Movement ◽  
Respiratory Illness ◽  
Control Measures ◽  
Travel Restrictions ◽  
Novel Coronavirus ◽  
National Emergency ◽  
And Control ◽  
The Impact

AbstractRespiratory illness caused by a novel coronavirus (COVID-19) appeared in China during December 2019. Attempting to contain infection, China banned travel to and from Wuhan city on 23 January and implemented a national emergency response. Here we evaluate the spread and control of the epidemic based on a unique synthesis of data including case reports, human movement and public health interventions. The Wuhan shutdown slowed the dispersal of infection to other cities by an estimated 2.91 days (95%CI: 2.54-3.29), delaying epidemic growth elsewhere in China. Other cities that implemented control measures pre-emptively reported 33.3% (11.1-44.4%) fewer cases in the first week of their outbreaks (13.0; 7.1-18.8) compared with cities that started control later (20.6; 14.5-26.8). Among interventions investigated here, the most effective were suspending intra-city public transport, closing entertainment venues and banning public gatherings. The national emergency response delayed the growth and limited the size of the COVID-19 epidemic and, by 19 February (day 50), had averted hundreds of thousands of cases across China.One sentence summaryTravel restrictions and the national emergency response delayed the growth and limited the size of the COVID-19 epidemic in China.

scholarly journals Outbreak analysis with a logistic growth model shows COVID-19 suppression dynamics in China

2020 ◽  
Author(s):  
Yi Zou ◽  
Stephen Pan ◽  
Peng Zhao ◽  
Lei Han ◽  
Xiaoxiang Wang ◽  
...  
Keyword(s):  
Growth Model ◽  
Mainland China ◽  
Logistic Growth ◽  
Complete Suppression ◽  
Virus Growth ◽  
Rate Of Increase ◽  
Decline Curves ◽  
Major Outbreak ◽  
Logistic Growth Model ◽  
Novel Coronavirus

AbstractChina reported a major outbreak of a novel coronavirus, SARS-CoV2, from mid-January till mid-March 2020. The number of cases outside China is now growing fast, while in mainland China the virus outbreak is largely under control. We review the epidemic virus growth and decline curves in China using a phenomenological logistic growth model to summarize the outbreak dynamics using three parameters that characterize the epidemic’s timing, rate and peak. During the initial phase, the number of virus cases doubled every 2.7 (range 2.2 - 4.4) days. The rate of increase in the number of reported cases peaked approximately 10 days after suppression measures were started on 23-25 January 2020. The peak in the number of reported sick cases occurred on average 18 days after the start of measures. From the time of starting measures till the peak, the number of cases increased by a factor 39 in the province Hubei, and by a factor 9.5 for all of China (range: 6.2-20.4 in the other provinces). Complete suppression took up to 2 months (range: 23-57d.), during which period severe restrictions, social distancing measures, testing and isolation of cases were in place. The suppression of the disease in China has been successful, demonstrating that suppression is a viable strategy to contain SARS-CoV2.

scholarly journals Moving-average based index to timely evaluate the current epidemic situation after COVID-19 outbreak

2020 ◽  
Author(s):  
He Yun-ting ◽  
Wang Xiao-jin ◽  
He Hao ◽  
Zhai Jing ◽  
Wang Bing-shun
Keyword(s):  
Local Governments ◽  
Control Strategies ◽  
Moving Average ◽  
National Level ◽  
Control Measures ◽  
Evolutionary Trend ◽  
Local Conditions ◽  
Management Measures ◽  
Imported Cases ◽  
Novel Coronavirus

[ABSTRACT]A pneumonia outbreak caused by a novel coronavirus (COVID-19) occurred in Wuhan, China at the end of 2019 and then spread rapidly to the whole country. A total of 81,498 laboratory-confirmed cases, including 3,267 deaths (4.0%) had been reported in China by March 22, 2020, meanwhile, 210,644 laboratory-confirmed cases and 9,517 deaths (4.5%) were reported outside China. Common symptoms of COVID-19 pneumonia included fever, fatigue and dry cough. In face of such a sudden outbreak of emerging novel infectious diseases, we have no history to learn from and no evidence to count on. Traditional models often predict inconsistent results. There is an urgent need to establish a practical data-driven method to predict the evolutionary trend of the epidemic, track and prejudge the current epidemic situation after the COVID-19 outbreak. Here we propose a simple, directly and generally applicable index and we name it ‘epidemic evaluation index’ (EEI), which is constructed by 7-day moving average of the log-transformed daily new cases (LMA). EEI could be used to support the decision-making process and epidemic prevention and control strategies through the evaluation of the current epidemic situation. First, we used SARS epidemic data from Hong Kong in 2003 to verify the practicability of the new index, which shows that the index is acceptable. The EEI was then applied to the COVID-19 epidemic situation analysis. We found that the trend direction of different districts in China changed on different date during the epidemic. At the national level and at local Hubei Province level, the epidemic both peaked on February 9. While the peak occurred relatively earlier, i.e. on February 5 in other provinces. It demonstrated the effectiveness of decisive action and implementations of control measures made by Chinese governments. While local governments should adjust management measures based on local epidemic situation. Although the epidemic has eased since late February, continued efforts in epidemic control are still required to prevent transmission of imported cases in China. However, the global COVID-19 epidemic outside China continues to expand as indicated by the EEI we proposed. Currently, efforts have been made worldwide to combat the novel coronavirus pandemic. People all over the world should work together and governments of all countries should take efficient measures in the light of Chinas experience and according to national circumstances and local conditions.

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