scholarly journals Tracking the onset date of the community spread of SARS-CoV-2 in Western Countries

Author(s):  
Edson Delatorre ◽  
Daiana Mir ◽  
Tiago Gräf ◽  
Gonzalo Bello

ABSTRACTThe SARS-CoV-2 rapidly spread around the world during 2020, but the precise time in which the virus began to spread locally is currently unknown for most countries. Here, we estimate the probable onset date of the community spread of SARS-CoV-2 from the cumulative number of deaths reported during the early stage of the epidemic in Western Europe and the Americas. Our results support that SARS-CoV-2 probably started to spread locally in all western countries analyzed between the middle of January and early February 2020, thus long before community transmission was officially recognized and control measures were implemented.

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jieqi Lei ◽  
Xuyuan Wang ◽  
Yiming Zhang ◽  
Lian Zhu ◽  
Lin Zhang

As of the end of October 2020, the cumulative number of confirmed cases of COVID-19 has exceeded 45 million and the cumulative number of deaths has exceeded 1.1 million all over the world. Faced with the fatal pandemic, countries around the world have taken various prevention and control measures. One of the important issues in epidemic prevention and control is the assessment of the prevention and control effectiveness. Changes in the time series of daily new confirmed cases can reflect the impact of policies in certain regions. In this paper, a smooth transition autoregressive (STAR) model is applied to investigate the intrinsic changes during the epidemic in certain countries and regions. In order to quantitatively evaluate the influence of the epidemic control measures, the sequence is fitted to the STAR model; then, comparisons between the dates of transition points and those of releasing certain policies are applied. Our model well fits the data. Moreover, the nonlinear smooth function within the STAR model reveals that the implementation of prevention and control policies is effective in some regions with different speeds. However, the ineffectiveness is also revealed and the threat of a second wave had already emerged.


Author(s):  
Y. Arockia Suganthi ◽  
Chitra K. ◽  
J. Magelin Mary

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.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Zuiyuan Guo ◽  
Dan Xiao

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.


2020 ◽  
Vol 7 (1) ◽  
pp. 85-88 ◽  
Author(s):  
Kiran Sapkota ◽  
Ganesh Dangal ◽  
Madhu Koirala ◽  
Kalyan Sapkota ◽  
Asmita Poudel ◽  
...  

Coronavirus disease (COVID-19) outbreak, caused by the most recently discovered coronavirus, is currently affecting a large population across the globe. World health organization (WHO) has already declared COVID-19, a pandemic, and the world is fighting to contain the COVID-19 outbreak. Nepal has taken several preventive measures to control the coronavirus outbreak. However, some additional steps are needed to prevent community transmission of the disease. This brief communication discusses the government of Nepal actions and provides recommendations for the prevention and control of COVID-19 infection in Nepal.


2009 ◽  
Vol 14 (31) ◽  
Author(s):  
I Gutiérrez ◽  
A Litzroth ◽  
S Hammadi ◽  
H Van Oyen ◽  
C Gérard ◽  
...  

On 6 July 2009 the Belgian enhanced surveillance system for influenza-like illness among travellers returning from influenza A(H1N1)v affected areas detected a case linked to a rock festival which took place on 2-5 July. The health authorities implemented communication and control measures leading to the detection of aditional cases. This paper describes the outbreak and its impact on the management of the influenza pandemic in Belgium.


2021 ◽  
Author(s):  
Ibrahima Diouf ◽  
Souleymane Sy ◽  
Habib Senghor ◽  
Papa Fall ◽  
Diarra Diouf ◽  
...  

AbstractThe COVID-19 disease, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), is a very contagious disease that has killed many people around the world. According to the World Health Organization (WHO) data, the spread of the disease appears to be slower in Africa. Although a number of studies have been published on the relationship between meteorological parameters and COVID-19 transmission, the effects of climate conditions on COVID-19 remain largely unexplored and without consensus following the main research finding over Africa (often based on a single country or city). Here, using available epidemiological data over 275 days (i.e., from March 1 to November 30, 2020) taken from the European Center for Disease Prevention and Control of the European Union database and daily data of surface air temperature and humidity from the National Center for Environmental Prediction (NCEP), this paper investigates the potential contributions of climate conditions on COVID-19 transmission over 16 countries selected from three bioclimatic regions of Africa (i.e., Sahel, Maghreb and Gulf of Guinea). On average, our main findings highlight statistically significant inverse correlations between COVID-19 cases and temperature over the Maghreb and the Gulf of Guinea regions, whereas positive correlations are found in the Sahel, especially over the central part including Niger and Mali. Correlations with specific humidity and water vapor parameters display significant and positive values over the Sahelian and the Gulf of Guinean countries and negative values over the Maghreb countries. In other word, results imply that the COVID-19 pandemic transmission is influenced differently across the three bioclimatic regions: i) cold and dry environmental conditions over the Maghreb; ii) warm and humid conditions over the Sahel iii) cold and humid conditions over the Gulf of Guinea. These findings could be useful for decision-makers who plan public health and control measures in affected African countries and would have substantial implications for directing respiratory disease surveillance activities.


Bionatura ◽  
2020 ◽  
Vol 5 (4) ◽  
pp. 1410-1417
Author(s):  
Daniel Tinôco ◽  
Suzana Borschiver

The World Scientific Community has carried out several studies on the novel coronavirus, responsible for the current COVID-19 pandemic. This study aimed to verify the development level and research evolution on COVID-19, summarizing experts' main trends in the first half of 2020. The most cited articles focused on understanding the disease, addressing aspects of its transmission, viral activity period, symptoms, health complications, risk factors, and the estimate of new cases. These papers also focused on the treatment/prevention and management of COVID-19. Several drugs and alternative treatments have been investigated, such as the convalescent plasma transfusion and stem cell transplantation, while an efficient vaccine is developed. Prevention and control measures, such as social isolation and immediate case identification, were also investigated. Therefore, the main COVID-19 trends were identified and classified in disease, treatment/prevention, and pandemic management, contributing to scientific understanding and future studies.


2020 ◽  
Author(s):  
Xinyin Xu ◽  
Jing Zeng ◽  
Runyou Liu ◽  
Yang Liu ◽  
Xiaobo Zhou ◽  
...  

Abstract Background: The COVID-19 spread worldwide quickly. Exploring the epidemiological characteristics could provide a basis for responding to imported cases abroad and to formulate prevention and control strategies in areas where COVID-19 is still spreading rapidly. Methods: The number of confirmed cases, daily growth, incidence and length of time from the first reported case to the end of the local cases (i.e., non-overseas imported cases) were compared by spatial (geographical) and temporal classification and visualization of the development and changes of the epidemic situation by layers through maps. Results: In the first wave, a total of 539 cases were reported in Sichuan, with an incidence rate of 0.6462/100,000. The closer to Hubei the population centres were, the more pronounced the epidemic was. The peak in Sichuan Province occurred in the second week. Eight weeks after the Wuhan lockdown, the health crisis had eased. The longest epidemic length at the city level in China (except Wuhan, Taiwan, and Hong Kong) was 53 days, with a median of 23 days. Spatial autocorrelation analysis of China showed positive spatial correlation (Moran's Index >0, p<0.05). Most countries outside China began to experience a rapid rise in infection rates 4 weeks after their first case. Some European countries experienced that rise earlier than the USA. The pandemic in Germany, Spain, Italy, and China took 28, 29, 34, and 18 days, respectively, to reach the peak of daily infections, after their daily increase of up to 20 cases. During this time, countries in the African region and Southeast Asian region were at an early stage of infections, those in the Eastern Mediterranean region and region of the Americas were in a rapid growth phase. Conclusions: After the closure of the outbreak city, appropriate isolation and control measures in the next 8 weeks were key to control the outbreak, which reduced the peak value and length of the outbreak. Some countries with improved epidemic situations need to develop a continuous "local strategy at entry checkpoints" to respond to a possible second local epidemic.


2020 ◽  
Author(s):  
Qing Zheng ◽  
Lei Wang ◽  
Hongbin Wang ◽  
Wenjing Gui

Abstract COVID-19 has been spreading around the world since the end of 2019, and there is no sign of a slowdown. Previous studies on seasonality of similar infectious diseases have hinted that meteorological factors may influence COVID-19 outbreaks as well1. Here we show, based on data collected in 132 cities of China, that relative humidity, as an essential meteorological indicator, is positively correlated with the growth rate of incidence of COVID-19, which contradicts previous research findings. Our result suggests an increasing risk of COVID-19 cases as summer and rain seasons arrive in many places of the world. They also help countries and regions to formulate pandemic prevention and control measures and policies according to local meteorological characteristics.


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