scholarly journals Estimating the Prevalence of Asymptomatic COVID-19 Cases and Their Contribution in Transmission - Using Henan Province, China, as an Example

2021 ◽  
Vol 8 ◽  
Author(s):  
Chunyu Li ◽  
Yuchen Zhu ◽  
Chang Qi ◽  
Lili Liu ◽  
Dandan Zhang ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Early Stage ◽  
Henan Province ◽  
Substantial Proportion ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
The World ◽  
Asymptomatic Infections ◽  
Novel Coronavirus

Background: Novel coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-COV-2), is now sweeping across the world. A substantial proportion of infections only lead to mild symptoms or are asymptomatic, but the proportion and infectivity of asymptomatic infections remains unknown. In this paper, we proposed a model to estimate the proportion and infectivity of asymptomatic cases, using COVID-19 in Henan Province, China, as an example.Methods: We extended the conventional susceptible-exposed-infectious-recovered model by including asymptomatic, unconfirmed symptomatic, and quarantined cases. Based on this model, we used daily reported COVID-19 cases from January 21 to February 26, 2020, in Henan Province to estimate the proportion and infectivity of asymptomatic cases, as well as the change of effective reproductive number, Rt.Results: The proportion of asymptomatic cases among COVID-19 infected individuals was 42% and the infectivity was 10% that of symptomatic ones. The basic reproductive number R0 = 2.73, and Rt dropped below 1 on January 31 under a series of measures.Conclusion: The spread of the COVID-19 epidemic was rapid in the early stage, with a large number of asymptomatic infected individuals having relatively low infectivity. However, it was quickly brought under control with national measures.

scholarly journals Epidemic Dynamics of COVID-19 Based on SEAIUHR Model Considering Asymptomatic Cases in Henan Province, China

2020 ◽  
Author(s):  
Chunyu Li ◽  
Yuchen Zhu ◽  
Chang Qi ◽  
Lili Liu ◽  
Dandan Zhang ◽  
...  
Keyword(s):  
Early Stage ◽  
Henan Province ◽  
Control Measures ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Infected People ◽  
Epidemic Dynamics ◽  
Global Pandemic ◽  
Prevention And Control Measures ◽  
Novel Coronavirus

Abstract Background New coronavirus disease (COVID-19), an infectious disease caused by a type of novel coronavirus, has emerged in various countries since the end of 2019 and caused a global pandemic. Many infected people went undetected because their symptoms were mild or asymptomatic, but the proportion and infectivity of asymptomatic infections remained unknown. Therefore, in this paper, we analyzed the proportion and infectivity of asymptomatic cases, as we as the prevalence of COVID-19 in Henan province. Methods We constructed SEAIUHR model based on COVID-19 cases reported from 21 January to 26 February 2020 in Henan province to estimate the proportion and infectivity of asymptomatic cases, as we as the change of effective reproductive number, \({R}_{t}\). At the same time, we simulated the changes of cases in different scenarios by changing the time and intensity of the implementation of prevention and control measures. Results The proportion of asymptomatic cases among COVID-19 infected individuals was 42% and infectivity of asymptomatic cases was 10% of that symptomatic ones. The basic reproductive number\({R}_{0}\)=2.73, and \({R}_{t}\) dropped below 1 on 1 February under a series of measures. If measures were taken five days earlier, the number of cases would be reduced by 2/3, and after 5 days the number would more than triple. Conclusions In Henan Province, the COVID-19 epidemic spread rapidly in the early stage, and there were a large number of asymptomatic infected individuals with relatively low infectivity. However, the epidemic was quickly brought under control with national measures, and the earlier measures were implemented, the better.

scholarly journals Evaluating new evidence in the early dynamics of the novel coronavirus COVID-19 outbreak in Wuhan, China with real time domestic traffic and potential asymptomatic transmissions

2020 ◽  
Author(s):  
Can Zhou
Keyword(s):  
Real Time ◽  
Early Stage ◽  
Empirical Support ◽  
Credible Interval ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
The Novel ◽  
Sources Of Information ◽  
Alternative Sources ◽  
Novel Coronavirus

AbstractThe novel coronavirus (COVID-19), first detected in Wuhan, China in December 2019, has spread to 28 countries/regions with over 43,000 confirmed cases. Much about this outbreak is still unknown. At this early stage of the epidemic, it is important to investigate alternative sources of information to understand its dynamics and spread. With updated real time domestic traffic, this study aims to integrate recent evidence of international evacuees extracted from Wuhan between Jan. 29 and Feb. 2, 2020 to infer the dynamics of the COVD-19 outbreak in Wuhan. In addition, a modified SEIR model was used to evaluate the empirical support for the presence of asymptomatic transmissions. Based on the data examined, this study found little evidence for the presence of asymptomatic transmissions. However, it is still too early to rule out its presence conclusively due to sample size and other limitations. The updated basic reproductive number was found to be 2.12 on average with a 95% credible interval of [2.04, 2.18]. It is smaller than previous estimates probably because the new estimate factors in the social and non-pharmaceutical mitigation implemented in Wuhan through the evacuee dataset. Detailed predictions of infected individuals exported both domestically and internationally were produced. The estimated case confirmation rate has been low but has increased steadily to 23.37% on average. The findings of this study depend on the validity of the underlying assumptions, and continuing work is needed, especially in monitoring the current infection status of Wuhan residents.

scholarly journals Clinical and Epidemiological Characteristics of Coronavirus Disease 2019 in the Early Stage of Outbreak

2020 ◽  
Vol 95 (2) ◽  
pp. 67-73 ◽  
Author(s):  
Jung Yeon Heo
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Large Scale ◽  
Early Stage ◽  
Central China ◽  
First Report ◽  
The World ◽  
Novel Coronavirus ◽  
Epidemiological Characteristics

In December 2019, a novel coronavirus, which is now designated as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first identified as the etiology of pneumonia of unknown cause in patients from Wuhan of central China. Since the first report of coronavirus disease 2019 (COVID-19), the disease became pandemic causing the large-scale outbreak all over the world. In this review, we discuss the clinical and epidemiological characteristics of COVID-19 in the early stage of outbreak based on recent reports from China.

scholarly journals Does the novel coronavirus 2019 like heart more than the other family members of coronaviruses?

2020 ◽  
Vol 12 (2) ◽  
pp. 156-157
Author(s):  
Mohammad Mostafa Ansari Ramandi ◽  
Mohammadreza Baay ◽  
Nasim Naderi
Keyword(s):  
Middle East ◽  
Severe Acute Respiratory Syndrome ◽  
Family Members ◽  
Middle East Respiratory Syndrome ◽  
The Other ◽  
The Novel ◽  
The World ◽  
Future Challenges ◽  
Novel Coronavirus ◽  
Coronavirus Infections

The disaster due to the novel coronavirus disease 2019 (COVID-19) around the world has made investigators enthusiastic about working on different aspects of COVID-19. However, although the pandemic of COVID-19 has not yet ended, it seems that COVID-19 compared to the other coronavirus infections (the Middle East Respiratory Syndrome [MERS] and Severe Acute Respiratory Syndrome [SARS]) is more likely to target the heart. Comparing the previous presentations of the coronavirus family and the recent cardiovascular manifestations of COVID-19 can also help in predicting possible future challenges and taking measures to tackle these issues.

scholarly journals Molecular Docking Study of the Potential Relevance of the Natural Compounds Isoflavone and Myricetin to COVID-19

2021 ◽  
Vol 25 (3) ◽  
pp. 271-282
Author(s):  
Didik Priyandoko ◽  
◽  
Wahyu Widowati ◽  
Mawar Subangkit ◽  
Diana Jasaputra ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Severe Acute Respiratory Syndrome ◽  
Active Sites ◽  
Docking Study ◽  
Binding Mode ◽  
Molecular Docking Study ◽  
Wuhan City ◽  
The World ◽  
Novel Coronavirus ◽  
Proteins Interactions

The 2019 novel coronavirus (2019-nCoV) or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread rapidly from its origin in Wuhan City, Hubei Province, China, to the rest of the world. The efficacy of herbal treatment in the control of contagious disease was demonstrated during the 2003 outbreak of severe acute respiratory syndrome (SARS). Natural compound used for this study were isoflavone and myricetin. Molecular docking was performed to analyze binding mode of the compounds towards 12 proteins related to COVID-19. The prediction shows that isoflavone and myricetin have moderate probability of antiviral activity. All of the docked compounds occupied the active sites of the proteins related to COVID-19. Based on QSAR and molecular docking, interactions were predicted with 10 out of 12 potential COVID-19 proteins for myricetin and with 9 out of 12 proteins interactions for isoflavone. A potential disease alleviating action is suggested for isoflavone and myricetin in the context of COVID-19 infection.

Modeling and stability analysis of the spread of novel coronavirus disease COVID-19

2021 ◽  
pp. 2150035
Author(s):  
A. George Maria Selvam ◽  
Jehad Alzabut ◽  
D. Abraham Vianny ◽  
Mary Jacintha ◽  
Fatma Bozkurt Yousef
Keyword(s):  
Fractional Order ◽  
Disease Transmission ◽  
Equilibrium Points ◽  
Sufficient Conditions ◽  
Basic Reproductive Number ◽  
Phase Portraits ◽  
Transmission Model ◽  
Reproductive Number ◽  
Discrete Version ◽  
Novel Coronavirus

Towards the end of 2019, the world witnessed the outbreak of Severe Acute Respiratory Syndrome Coronavirus-2 (COVID-19), a new strain of coronavirus that was unidentified in humans previously. In this paper, a new fractional-order Susceptible–Exposed–Infected–Hospitalized–Recovered (SEIHR) model is formulated for COVID-19, where the population is infected due to human transmission. The fractional-order discrete version of the model is obtained by the process of discretization and the basic reproductive number is calculated with the next-generation matrix approach. All equilibrium points related to the disease transmission model are then computed. Further, sufficient conditions to investigate all possible equilibria of the model are established in terms of the basic reproduction number (local stability) and are supported with time series, phase portraits and bifurcation diagrams. Finally, numerical simulations are provided to demonstrate the theoretical findings.

Tri-primer-enhanced strand exchange amplification combined with rapid lateral flow fluorescent immunoassay to detect SARS-CoV-2

The Analyst ◽  
2021 ◽  
Author(s):  
Linlin Zhuang ◽  
Jiansen Gong ◽  
Ming Ma ◽  
Yongxin Ji ◽  
Peilong Tian ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Lateral Flow ◽  
Strand Exchange ◽  
The Novel ◽  
The World ◽  
Novel Coronavirus

The novel coronavirus disease 2019 caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been surging rapidly around the world, which exposes humanity to unprecedented economic, social and...

scholarly journals A Simulation on Potential Secondary Spread of Novel Coronavirus in an Exported Country Using a Stochastic Epidemic SEIR Model

2020 ◽  
Vol 9 (4) ◽  
pp. 944 ◽  
Author(s):  
Kentaro Iwata ◽  
Chisato Miyakoshi
Keyword(s):  
Healthcare Professionals ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Asian Countries ◽  
Hospital Visit ◽  
Seir Model ◽  
Stochastic Epidemic ◽  
Novel Coronavirus ◽  
The Impact ◽  
Multiple Scenarios

Ongoing outbreak of pneumonia caused by novel coronavirus (2019-nCoV) began in December 2019 in Wuhan, China, and the number of new patients continues to increase. Even though it began to spread to many other parts of the world, such as other Asian countries, the Americas, Europe, and the Middle East, the impact of secondary outbreaks caused by exported cases outside China remains unclear. We conducted simulations to estimate the impact of potential secondary outbreaks in a community outside China. Simulations using stochastic SEIR model were conducted, assuming one patient was imported to a community. Among 45 possible scenarios we prepared, the worst scenario resulted in the total number of persons recovered or removed to be 997 (95% CrI 990–1000) at day 100 and a maximum number of symptomatic infectious patients per day of 335 (95% CrI 232–478). Calculated mean basic reproductive number (R0) was 6.5 (Interquartile range, IQR 5.6–7.2). However, better case scenarios with different parameters led to no secondary cases. Altering parameters, especially time to hospital visit. could change the impact of a secondary outbreak. With these multiple scenarios with different parameters, healthcare professionals might be able to better prepare for this viral infection.

scholarly journals Coronavirus Pandemic: a major public health crisis for the developed and developing world

2021 ◽  
Vol 15 (03) ◽  
pp. 366-369
Author(s):  
Rooh Ullah ◽  
Muhammad Suleman Rana ◽  
Mehmood Qadir ◽  
Muhammad Usman ◽  
Niaz Ahmed
Keyword(s):  
Public Health ◽  
Severe Acute Respiratory Syndrome ◽  
Viral Infection ◽  
The Novel ◽  
Global Public Health ◽  
Health Crisis ◽  
Public Health Crisis ◽  
The World ◽  
Novel Coronavirus ◽  
Day By Day

Pandemic of novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infections in China is now become global public health crisis. At present 87.64% of the world is infected by this deadly illness. The risk from this epidemic depends on the nature of the virus, including how well it transmits from person to person, and the complications resulting from this current illness. The novel coronavirus has killed thousands of people in China and other countries as well; its rate of mortality is increasing day by day. There is an urgent need to control the virus by developing vaccine or any other antiviral drugs to save the world from this deadly viral infection.

scholarly journals How to Face COVID-19 in Ophthalmology Practice

2020 ◽  
Vol 9 (3) ◽  
pp. 164-171 ◽  
Author(s):  
Xiaoting Pei ◽  
Xinwei Jiao ◽  
Dingli Lu ◽  
Di Qi ◽  
Shenzhen Huang ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Severe Acute Respiratory Syndrome ◽  
Search Strategy ◽  
International Community ◽  
The Novel ◽  
The World ◽  
Novel Coronavirus

Background: The novel coronavirus pneumonia has attracted considerable attention from the international community. With the spread of outbreaks around the world, the WHO characterized COVID-19 as a pandemic. Methods: Relevant studies in PubMed were searched from January 1, 2020 to April 12, 2020, using the following search strategy: (“novel coronavirus pneumonia” OR “severe acute respiratory syndrome coronavirus 2” OR “coronavirus disease 2019” OR “COVID-19” OR “novel coronavirus pneumonia”) AND (“ophthalmology” OR “ophthalmologist” OR “eye” OR “conjunctiva” OR “conjunctivitis” OR “corneal” OR “keratitis”). Results: SARS-CoV-2 can spread through aerosol and is detected in tears of patients with COVID-19 infection. Notably, some infected patients had conjunctivitis, and conjunctivitis was the first symptom in some patients later diagnosed to have COVID-19 infection. This would increase the risk for ophthalmologists through inpatient consultations or regular clinical practice. When dealing with seemingly regular ophthalmic patients, the vigilance of ophthalmologists and associated staff tends to be reduced. Conclusion: Ophthalmologists must continuously update their knowledge regarding COVID-19 and take effective measures to prevent COVID-19 transmission.

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