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1.
Meteorological Applications ; 29(5), 2022.
Article in English | Web of Science | ID: covidwho-2068579

ABSTRACT

Laboratory experiments have revealed the meteorological sensitivity of the coronavirus disease 2019 (COVID-19) virus. However, no consensus has been reached about how outdoor meteorological conditions modulate the virus transmission as it is also constrained by non-meteorological conditions. Here, we identify the outbreak's evolution stage, constrained least by non-meteorological conditions, by searching the maximum correlation coefficient between the ultraviolet flux and the growth rate of cumulative confirmed cases at the country level. At this least-constrained stage, the cumulative cases count around 1300-3200, and the count's daily growth rate correlates with the ultraviolet flux and temperature significantly (correlation coefficients r = -0.54 +/- 0.09 and -0.39 +/- 0.10 at p<0.01$$ p, respectively), but not with precipitation, humidity, and wind. The ultraviolet correlation exhibits a delay of about 7 days, providing a meteorological measure of the incubation period. Our work reveals a seasonality of COVID-19 and a high risk of a pandemic resurgence in winter, implying a need for seasonal adaption in public policies.

2.
Novel AI and Data Science Advancements for Sustainability in the Era of COVID-19 ; : 113-158, 2022.
Article in English | Scopus | ID: covidwho-2035528

ABSTRACT

COVID-19 has been declared as a “pandemic” by the World Health Organization (WHO) and has claimed more than a million lives and over 50 million confirmed cases worldwide as of 7th November 2020. This virus can be curbed in only two ways: vaccination and other by imposing non-pharmaceutical interventions (NPIs), which are behavioral changes to a person and community. Most of the nations worldwide have imposed NPIs in the form of social distancing and lockdowns, which have been effective in reducing the pace of the virus's spread, but continued implementation has deemed social and economic losses. Hence strategic implementation of NPIs in a burst of periods should be done based on educated decisions using data about population mobility trends to find hot zones that lead to a spike in cases. These decisions will positively impact the virus's spread with lower damage to social and economic aspects. © 2022 Elsevier Inc. All rights reserved.

3.
Gaceta Medica de Caracas ; 130:S436-S449, 2022.
Article in Spanish | Scopus | ID: covidwho-1995011

ABSTRACT

The end of the pandemic could be marked, not by the total eradication of the virus but by a decrease in cases and seasonal peaks in the frequency of SARSCoV-2. Although this has already happened with the influenza A (H1N1) pdm09 virus responsible for the 2009 pandemic, unlike on that occasion, many of the countries that have widely covered their population with the vaccination scheme, still receive the onslaught of COVID-19 and have resumed containment measures due to the appearance, above all, of new variants. The latter suggests that the path to SARS-CoV-2 seasonality may not be as benevolent as the 2009 influenza virus was. Therefore, it is necessary to study the characteristics by which this new virus can acquire seasonality. to consider this scenario and take the necessary measures to face it from a different perspective. © 2022 Academia Nacional de Medicina. All rights reserved.

4.
Chinese Journal of Nosocomiology ; 31(24):3703-3707, 2021.
Article in English, Chinese | GIM | ID: covidwho-1990047

ABSTRACT

COVID-2019 has become a global pandemic, and a variety of SARS-CoV-2 variants have emerged with the continuous evolution and variation. SARS-CoV-2 Delta VOC (B.1.617.2) has the characteristics of strong transmission, short incubation period of infection, high pathogenicity and rapid disease progression, which has gradually become the main epidemic strain in India and even in the world, leading to countries and regions of the epidemic rebound. In this paper, the current epidemic characteristics and core control measures of SARS-CoV-2 Delta VOC was reviewed.

5.
Journal of Shandong University ; 58(10):38-43, 2020.
Article in Chinese | GIM | ID: covidwho-1975280

ABSTRACT

Objective: To explore epidemic dynamics of coronavirus disease 2019 (COVID-19) in Xinyang City so as to provide scientific basis for optimizing the prevention and control strategies and evaluating the effects of intervention.

6.
Journal of Shandong University ; 58(10):100-104, 2020.
Article in Chinese | GIM | ID: covidwho-1975279

ABSTRACT

Objective: To investigate a family cluster of coronavirus disease 2019(COVID-19)in Zibo, so as to analyze the characteristics of the epidemic.

7.
One Health ; 15: 100425, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-1966972

ABSTRACT

Based on exposure history and symptom onset of 22 Omicron BA.1 cases in South Korea from November to December 2021, we estimated mean incubation period of 3.5 days (95% CI: 2.5, 3.8), and then compared to that of 6.5 days (95% CI: 5.3, 7.7) for 64 cases during Delta variants' dominance in June 2021. For Omicron BA.1 variants, we found that 95% of symptomatic cases developed clinical conditions within 6.0 days (95% CI: 4.3, 6.6) after exposure. Thus, a shorter quarantine period may be considered based on symptoms, or similarly laboratory testing, when Omicron BA.1 variants are circulating.

8.
Infect Dis Model ; 7(3): 473-485, 2022 Sep.
Article in English | MEDLINE | ID: covidwho-1966617

ABSTRACT

In this study, we determine and compare the incubation duration, serial interval, pre-symptomatic transmission, and case fatality rate of MERS-CoV and COVID-19 in Saudi Arabia based on contact tracing data we acquired in Saudi Arabia. The date of infection and infector-infectee pairings are deduced from travel history to Saudi Arabia or exposure to confirmed cases. The incubation times and serial intervals are estimated using parametric models accounting for exposure interval censoring. Our estimations show that MERS-CoV has a mean incubation time of 7.21 (95% CI: 6.59-7.85) days, whereas COVID-19 (for the circulating strain in the study period) has a mean incubation period of 5.43(95% CI: 4.81-6.11) days. MERS-CoV has an estimated serial interval of 14.13(95% CI: 13.9-14.7) days, while COVID-19 has an estimated serial interval of 5.1(95% CI: 5.0-5.5) days. The COVID-19 serial interval is found to be shorter than the incubation time, indicating that pre-symptomatic transmission may occur in a significant fraction of transmission events. We conclude that during the COVID-19 wave studied, at least 75% of transmission happened prior to the onset of symptoms. The CFR for MERS-CoV is estimated to be 38.1% (95% CI: 36.8-39.5), while the CFR for COVID-19 1.67% (95% CI: 1.63-1.71). This work is expected to help design future surveillance and intervention program targeted at specific respiratory virus outbreaks, and have implications for contingency planning for future coronavirus outbreaks.

9.
Shanghai Journal of Preventive Medicine ; 33(11):1035-1039, 2021.
Article in Chinese | GIM | ID: covidwho-1934808

ABSTRACT

Objective: To analyze the incidence and epidemic characteristics of local cases infected with SARS-CoV-2 in Yangpu District of Shanghai, China, and provide scientific evidence for the prevention and control of coronavirus disease-19 (COVID-19).

10.
Cardiovascular Therapy & Prevention ; - (6):89-98, 2022.
Article in Russian | Academic Search Complete | ID: covidwho-1934750

ABSTRACT

Despite the decrease in the incidence rate, today the problem of a co- ronavirus disease 2019 (COVID-19) remains relevant on a global scale. Among the Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) variants, the Omicron is currently dominant. The differentiating properties of the Omicron variant are a shorter incubation period (1-5 days), high contagiousness, and a relatively mild course of the disease, which is associated with the highest number of genome mutations among all SARS-CoV-2 variants. The new variant is characterized by upper respiratory tract symptoms: rhinorrhea, severe sore throat, sneezing, less commonly cough, headache, and weakness. Oral antiviral drugs Paxlovid and Molnupiravir are effective for treating mild to moderate COVID-19, including in outpatients. While corticosteroids and interleukin-6 receptor antagonists are still effective in treating patients with moderate to severe COVID-19, the effectiveness of anti-SARS-CoV-2 monoclonal antibodies has not yet been fully proven. Vaccination, especially booster doses, against SARS-CoV-2 is the most effective method of preventing COVID-19. The review purpose was to analyze the literature to determine the key aspects of prevention, clinical picture and treatment of a new SARSCoV- 2 Omicron variant. The work used publications for the period from November 2021 to February 25, 2022, dedicated to the prevention, diagnosis and treatment of COVID-19 caused by the Omicron variant from the following databases: PubMed, eLibrary, MedRxiv, Google Scholar. The following key words were used: "Omicron", "SARS CoV-2", "COVID-19", "Omicron treatment". The analysis showed that COVID-19 caused by the Omicron variant is characterized by a relatively mild course. However, due to high contagiousness, this variant poses a significant problem due to the excessive load on outpatient and inpatient healthcare, including intensive care units. (English) [ FROM AUTHOR] Несмотря на снижение уровня заболеваемости, на сегодняш- ний день проблема новой коронавирусной инфекции (COVID-19, COronaVIrus Disease 2019) в глобальном масштабе остается ак- туальной. Среди вариантов вируса SARS-CoV-2 (Severe Acute Respiratory Syndrome CoronaVirus 2) на сегодняшний день штамм Омикрон является доминирующим. Отличительными свойствами нового штамма являются более короткий инкубационный период (1-5 сут.), высокая контагиозность, относительно легкое течение заболевания, что связано с наибольшим среди всех вариантов вируса SARS-CoV-2 числом мутаций в геноме. Для нового штам- ма характерны симптомы поражения верхних дыхательных путей: насморк, выраженная боль в горле, чихание, реже -- кашель, го- ловная боль, слабость. Пероральные противовирусные препараты Паксловид и Молнупиравир эффективны для лечения при легкой и среднетяжелой формах COVID-19, в т.ч. на амбулаторном этапе медицинской помощи. При лечении пациентов со среднетяжелыми и тяжелыми случаями COVID-19 по-прежнему эффективны корти- костероиды и блокаторы рецепторов интерлейкина-6, эффектив- ность анти-SARS-CoV-2 моноклональных антител на сегодняшний день полностью не доказана. Вакцинация, особенно с применени- ем бустерных доз, против SARS-CoV-2 является наиболее эффек- тивным методом предотвращения и ликвидации COVID-19. Цель обзора -- анализ литературы для определения ключевых аспектов профилактики, клиники и лечения нового варианта вируса SARSCoV- 2 Омикрон. В работе использованы источники из научных баз PubMed, eLibrary, MedRxiv, Google Scholar, опубликованных за пе- риод с ноября 2021 по 25 февраля 2022гг, посвященных профи- лактике, диагностике и лечению COVID-19, вызываемой штаммом вируса SARS-CoV-2 Омикрон. В качестве ключевых слов исполь- зованы: "Омикрон/Omicron", "SARS-CoV-2", "COVID-19", "Omicron treatment". На основании анализа можно сделать вывод, что COVID-19, вызванная штаммом Омикрон, характеризуется относи- тельно легким течением, однако из-за его высокой контагиозности данный штамм представляет существенную проблему вследствие избыточной нагрузки на амбулаторное и на стационарное звено здравоохранения, включая отделения реанимации и интенсивной терапии. (Russian) [ FROM AUTHOR] Copyright of Cardiovascular Therapy & Prevention is the property of Silicea-Poligraf LLC and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

11.
Gastroenterologe ; 15(6): 443-451, 2020.
Article in German | MEDLINE | ID: covidwho-1919922

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a beta coronavirus, which first appeared in 2019 and rapidly spread causing a worldwide pandemic. Here we present a nonsystematic review of the current knowledge on its epidemiological features. The SARS-CoV­2 replicates mainly in the upper and lower respiratory tract and is mainly transmitted by droplets and aerosols from asymptomatic and symptomatic infected subjects. The estimate for the basic reproduction number (R0) is between 2 and 3 and the median incubation period is 6 days (range 2-14 days). Similar to the related coronaviruses SARS and Middle East respiratory syndrome (MERS), superspreading events play an important role in spreading the disease. The majority of infections run an uncomplicated course but 5-10% of those infected develop pneumonia or a systemic inflammation leading to hospitalization, respiratory and potentially multiorgan failure. The most important risk factors for a complicated disease course are age, hypertension, diabetes, chronic cardiovascular and pulmonary diseases and immunodeficiency. The current infection fatality rate over all age groups is between 0.5% and 1% and the rate rises after the sixth decade of life. Nosocomial transmission and infections in medical personnel have been reported. A drastic reduction of social contacts has been implemented in many countries with outbreaks of SARS-CoV­2, leading to rapid reductions in R0. Most interventions have used bundles and which of the measures have been more effective is still unknown. Using mathematical models an incidence of 0.4%-1.8% can be estimated for the first wave in Germany.

12.
J Clin Med ; 11(14)2022 Jul 06.
Article in English | MEDLINE | ID: covidwho-1917564

ABSTRACT

Pre-symptomatic transmission potentially reduces the effectiveness of symptom-onset-based containment and control strategies for the coronavirus disease (COVID-19). Despite evidence from multiple settings, the proportion of pre-symptomatic transmission varies among countries. To estimate the extent of pre-symptomatic transmission in South Korea, we used individual-level COVID-19 case records from the Korea Disease Control and Prevention Agency and Central Disease Control Headquarters. We inferred the probability of symptom onset per day since infection based on the density distribution of the incubation period to stratify the serial interval distribution in Period 1 (20 January-10 February 2020) and Period 2 (25 July-4 December 2021), without and with expanded testing or implementation of social distancing strategies, respectively. Assuming both no correlation as well as positive and negative correlations between the incubation period and the serial interval, we estimated the proportion of pre-symptomatic transmission in South Korea as 43.5% (accounting for correlation, range: 9.9-45.4%) and 60.0% (56.2-64.1%) without and with expanded testing, respectively, during the Delta variant's predominance. This study highlights the importance of considering pre-symptomatic transmission for COVID-19 containment and mitigation strategies because pre-symptomatic transmission may play a key role in the epidemiology of COVID-19.

13.
Int J Environ Res Public Health ; 19(10)2022 05 23.
Article in English | MEDLINE | ID: covidwho-1903378

ABSTRACT

We aimed to elucidate the range of the incubation period in patients infected with the SARS-CoV-2 Omicron variant in comparison with the Alpha variant. Contact tracing data from three Japanese public health centers (total residents, 1.06 million) collected following the guidelines of the Infectious Diseases Control Law were reviewed for 1589 PCR-confirmed COVID-19 cases diagnosed in January 2022. We identified 77 eligible symptomatic patients for whom the date and setting of transmission were known, in the absence of any other probable routes of transmission. The observed incubation period was 3.03 ± 1.35 days (mean ± SDM). In the log-normal distribution, 5th, 50th and 95th percentile values were 1.3 days (95% CI: 1.0-1.6), 2.8 days (2.5-3.1) and 5.8 days (4.8-7.5), significantly shorter than among the 51 patients with the Alpha variant diagnosed in April and May in 2021 (4.94 days ± 2.19, 2.1 days (1.5-2.7), 4.5 days (4.0-5.1) and 9.6 days (7.4-13.0), p < 0.001). As this incubation period, mainly of sublineage BA.1, is even shorter than that in the Delta variant, it is thought to partially explain the variant replacement occurring in late 2021 to early 2022 in many countries.


Subject(s)
COVID-19 , Infectious Disease Incubation Period , SARS-CoV-2 , COVID-19/epidemiology , Contact Tracing , Humans , Japan/epidemiology , SARS-CoV-2/genetics , SARS-CoV-2/physiology
14.
Cureus ; 14(5): e24999, 2022 May.
Article in English | MEDLINE | ID: covidwho-1897124

ABSTRACT

Background The novel coronavirus disease (COVID-19) has become pandemic. For effective disease control, quarantine of the infected and exposed cases for an optimal period is critical. Currently, infected individuals are quarantined for 14 days. We tried to check if the quarantine period practiced is optimal in the Indian context. Methods This cross-sectional study was conducted in Odisha, India. We compiled and analyzed the information of 152 laboratory-confirmed SARS-CoV-2 positive cases. Descriptive analysis was conducted. Results Out of the 152 cases, 80% were males, 9.8% were symptomatic, 66.4% had travel history, and 53.9% had contact with COVID-19 cases. The incubation period ranged from 1-50 days with a median of 19.5 days (IQR: 17-27 days). The median periods were similar according to gender, history of contact, and presence of symptoms. Interestingly, 84.7% of the cases had an incubation period of more than 14 days. To cover 95% and 90% of the individuals, the quarantine period may have to be extended to 38 days and 35 days, respectively. Conclusion A longer observed incubation period (minimum 28 days) suggests the extension of the quarantine period for adults beyond the presently practiced 14 days. Considering the fast-spreading outbreak, an extended quarantine period for 28 days or active periodic follow-up could be more effective.

15.
Euro Surveill ; 27(6)2022 02.
Article in English | MEDLINE | ID: covidwho-1883863

ABSTRACT

The SARS-CoV-2 Omicron variant has a growth advantage over the Delta variant because of higher transmissibility, immune evasion or shorter serial interval. Using S gene target failure (SGTF) as indication for Omicron BA.1, we identified 908 SGTF and 1,621 non-SGTF serial intervals in the same period. Within households, the mean serial interval for SGTF cases was 0.2-0.6 days shorter than for non-SGTF cases. This suggests that the growth advantage of Omicron is partly due to a shorter serial interval.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Netherlands
16.
Euro Surveill ; 27(15)2022 04.
Article in English | MEDLINE | ID: covidwho-1869325

ABSTRACT

BackgroundHouseholds appear to be the highest risk setting for COVID-19 transmission. Large household transmission studies in the early stages of the pandemic in Asia reported secondary attack rates ranging from 5 to 30%.AimWe aimed to investigate the transmission dynamics of COVID-19 in household and community settings in the UK.MethodsA prospective case-ascertained study design based on the World Health Organization FFX protocol was undertaken in the UK following the detection of the first case in late January 2020. Household contacts of cases were followed using enhanced surveillance forms to establish whether they developed symptoms of COVID-19, became confirmed cases and their outcomes. We estimated household secondary attack rates (SAR), serial intervals and individual and household basic reproduction numbers. The incubation period was estimated using known point source exposures that resulted in secondary cases.ResultsWe included 233 households with two or more people with 472 contacts. The overall household SAR was 37% (95% CI: 31-43%) with a mean serial interval of 4.67 days, an R0 of 1.85 and a household reproduction number of 2.33. SAR were lower in larger households and highest when the primary case was younger than 18 years. We estimated a mean incubation period of around 4.5 days.ConclusionsRates of COVID-19 household transmission were high in the UK for ages above and under 18 years, emphasising the need for preventative measures in this setting. This study highlights the importance of the FFX protocol in providing early insights on transmission dynamics.


Subject(s)
COVID-19 , Adolescent , Family Characteristics , Humans , Pandemics , SARS-CoV-2 , United Kingdom/epidemiology
17.
International Conference on Modeling in Engineering 2020 ; 2383, 2022.
Article in English | Scopus | ID: covidwho-1860497

ABSTRACT

In this paper, we use the SEIR model to predict the outbreak of the novel coronavirus 2019-nCoV, and when the outbreak will begin. We predicted and compared the development of an outbreak where certain measures are taken and measures are not taken, and then we compared with the actual data of the city of Wuhan and study further approaches to responding to such outbreaks. © 2022 Author(s).

18.
Math Comput Simul ; 194: 1-18, 2022 Apr.
Article in English | MEDLINE | ID: covidwho-1851738

ABSTRACT

This manuscript describes a mathematical epidemiological model of COVID-19 to investigate the dynamics of this pandemic disease and we have fitted this model to the current COVID-19 cases in Italy. We have obtained the basic reproduction number which plays a crucial role on the stability of disease free equilibrium point. Backward bifurcation with respect to the cure rate of treatment occurs conditionally. It is clear from the sensitivity analysis that the developments of self immunities with proper maintaining of social distancing of the exposed and asymptomatic individuals play key role for controlling the disease. We have validated the model by considering the COVID-19 cases of Italy and the future situations of epidemicity in Italy have been predicted from the model. We have estimated the basic reproduction number for the COVID-19 outbreak in Italy and effective reproduction number has also been studied. Finally, an optimal control model has been formulated and solved to realize the positive impacts of adapting lock down by many countries for maintaining social distancing.

19.
BMC Pulm Med ; 22(1): 188, 2022 May 12.
Article in English | MEDLINE | ID: covidwho-1846823

ABSTRACT

BACKGROUND: Most severe, critical, or mortal COVID-19 cases often had a relatively stable period before their status worsened. We developed a deterioration risk model of COVID-19 (DRM-COVID-19) to predict exacerbation risk and optimize disease management on admission. METHOD: We conducted a multicenter retrospective cohort study with 239 confirmed symptomatic COVID-19 patients. A combination of the least absolute shrinkage and selection operator (LASSO), change-in-estimate (CIE) screened out independent risk factors for the multivariate logistic regression model (DRM-COVID-19) from 44 variables, including epidemiological, demographic, clinical, and lung CT features. The compound study endpoint was progression to severe, critical, or mortal status. Additionally, the model's performance was evaluated for discrimination, accuracy, calibration, and clinical utility, through internal validation using bootstrap resampling (1000 times). We used a nomogram and a network platform for model visualization. RESULTS: In the cohort study, 62 cases reached the compound endpoint, including 42 severe, 18 critical, and two mortal cases. DRM-COVID-19 included six factors: dyspnea [odds ratio (OR) 4.89;confidence interval (95% CI) 1.53-15.80], incubation period (OR 0.83; 95% CI 0.68-0.99), number of comorbidities (OR 1.76; 95% CI 1.03-3.05), D-dimer (OR 7.05; 95% CI, 1.35-45.7), C-reactive protein (OR 1.06; 95% CI 1.02-1.1), and semi-quantitative CT score (OR 1.50; 95% CI 1.27-1.82). The model showed good fitting (Hosmer-Lemeshow goodness, X2(8) = 7.0194, P = 0.53), high discrimination (the area under the receiver operating characteristic curve, AUROC, 0.971; 95% CI, 0.949-0.992), precision (Brier score = 0.051) as well as excellent calibration and clinical benefits. The precision-recall (PR) curve showed excellent classification performance of the model (AUCPR = 0.934). We prepared a nomogram and a freely available online prediction platform ( https://deterioration-risk-model-of-covid-19.shinyapps.io/DRMapp/ ). CONCLUSION: We developed a predictive model, which includes the including incubation period along with clinical and lung CT features. The model presented satisfactory prediction and discrimination performance for COVID-19 patients who might progress from mild or moderate to severe or critical on admission, improving the clinical prognosis and optimizing the medical resources.


Subject(s)
COVID-19 , COVID-19/diagnostic imaging , Cohort Studies , Humans , Infectious Disease Incubation Period , Lung/diagnostic imaging , Retrospective Studies , Tomography, X-Ray Computed
20.
Turkish Journal of Public Health ; 20(1):104-116, 2022.
Article in English | CAB Abstracts | ID: covidwho-1836210

ABSTRACT

Aim: This study is aimed to identify the awareness and behavioral perspective on COVID-19 between urban and rural people of Bangladesh during the period of outbreak.

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