scholarly journals Generic probabilistic modelling and non-homogeneity issues for the UK epidemic of COVID-19

2020 ◽  
Author(s):  
Anatoly Zhigljavsky ◽  
Roger Whitaker ◽  
Ivan Fesenko ◽  
Kobi Kremnizer ◽  
Jack Noonan ◽  
...  
Keyword(s):  
Age Groups ◽  
Mean Field ◽  
Social Contact ◽  
Forthcoming Paper ◽  
Control Parameters ◽  
Infected People ◽  
Robust Modelling ◽  
Key Variables ◽  
The Uk ◽  
Probabilistic Nature

AbstractCoronavirus COVID-19 spreads through the population mostly based on social contact. To gauge the potential for widespread contagion, to cope with associated uncertainty and to inform its mitigation, more accurate and robust modelling is centrally important for policy making.We provide a flexible modelling approach that increases the accuracy with which insights can be made. We use this to analyse different scenarios relevant to the COVID-19 situation in the UK. We present a stochastic model that captures the inherently probabilistic nature of contagion between population members. The computational nature of our model means that spatial constraints (e.g., communities and regions), the susceptibility of different age groups and other factors such as medical pre-histories can be incorporated with ease. We analyse different possible scenarios of the COVID-19 situation in the UK. Our model is robust to small changes in the parameters and is flexible in being able to deal with different scenarios.This approach goes beyond the convention of representing the spread of an epidemic through a fixed cycle of susceptibility, infection and recovery (SIR). It is important to emphasise that standard SIR-type models, unlike our model, are not flexible enough and are also not stochastic and hence should be used with extreme caution. Our model allows both heterogeneity and inherent uncertainty to be incorporated. Due to the scarcity of verified data, we draw insights by calibrating our model using parameters from other relevant sources, including agreement on average (mean field) with parameters in SIR-based models.We use the model to assess parameter sensitivity for a number of key variables that characterise the COVID-19 epidemic. We also test several control parameters with respect to their influence on the severity of the outbreak. Our analysis shows that due to inclusion of spatial heterogeneity in the population and the asynchronous timing of the epidemic across different areas, the severity of the epidemic might be lower than expected from other models.We find that one of the most crucial control parameters that may significantly reduce the severity of the epidemic is the degree of separation of vulnerable people and people aged 70 years and over, but note also that isolation of other groups has an effect on the severity of the epidemic. It is important to remember that models are there to advise and not to replace reality, and that any action should be coordinated and approved by public health experts with experience in dealing with epidemics.The computational approach makes it possible for further extensive scenario-based analysis to be undertaken. This and a comprehensive study of sensitivity of the model to different parameters defining COVID-19 and its development will be the subject of our forthcoming paper. In that paper, we shall also extend the model where we will consider different probabilistic scenarios for infected people with mild and severe cases.

scholarly journals Effects of latency and age structure on the dynamics and containment of COVID-19

2020 ◽  
Author(s):  
K.B. Blyuss ◽  
Y.N. Kyrychko
Keyword(s):  
Population Structure ◽  
Age Structure ◽  
Age Groups ◽  
Mean Field ◽  
Major Effect ◽  
Type Model ◽  
Mean Field Model ◽  
Age Structured ◽  
The Uk ◽  
Related Mortality

AbstractIn this paper we develop an SEIR-type model of COVID-19, with account for two particular aspects: non-exponential distribution of incubation and recovery periods, as well as age structure of the population. For the mean-field model, which does not distinguish between different age groups, we demonstrate that including a more realistic Gamma distribution of incubation and recovery periods may not have an effect on the total number of deaths and the overall size of an epidemic, but it has a major effect in terms of increasing the peak numbers of infected and critical care cases, as well as on changing the timescales of an epidemic, both in terms of time to reach the peak, and the overall duration of an outbreak. In order to obtain more accurate estimates of disease progression and investigate different strategies for introducing and lifting the lockdown, we have also considered an age-structured version of the model, which has allowed us to include more accurate data on age-specific rates of hospitalisation and COVID-19 related mortality. Applying this model to three comparable neighbouring regions in the UK has delivered some fascinating insights regarding the effect of quarantine in regions with different population structure. We have discovered that for a fixed quarantine duration, the timing of its start is very important in the sense that the second epidemic wave after lifting the quarantine can be significantly smaller or larger depending on the specific population structure. Also, the later the fixed-duration quarantine is introduced, the smaller is the resulting final number of deaths at the end of the outbreak. When the quarantine is introduced simultaneously for all regions, increasing quarantine duration postpones and slightly reduces the epidemic peak, though without noticeable differences in peak magnitude between different quarantine durations.

scholarly journals An Extended Bayesian Hierarchical Model Predicted SARS-CoV-2 Cases and Reproductions After Vaccination in England

CONVERTER ◽  
2021 ◽  
pp. 59-67
Author(s):  
Jiajing Zha, Xiangdong Liu
Keyword(s):  
Age Groups ◽  
Bayesian Hierarchical ◽  
Infected People ◽  
Public Health Emergencies ◽  
Global Pandemic ◽  
Mortality Ratio ◽  
Set Up ◽  
The Uk ◽  
Drug Interventions ◽  
Epidemiological Characteristics

In the UK, one of the worst affected countries by the SARS-CoV-2 global pandemic, the UK government has released a comprehensive vaccination plan for SARS-CoV-2 and will set up more vaccination sites in the coming months to expand the service to more people. We built an extended Bayesian hierarchical prediction model to predict the number of cases and breeding situation after vaccination in the nine districts of England. Based on the population of each region, the number of deaths and the IFR (the infection mortality ratio) for each region were predicted. We found that EAST, NORTHWEST and SOUTHEAST had the largest IFR, and the corresponding death numbers were 29,079, 28,734 and 25,201, respectively. Reproduction number ( ) is expected to drop below 1 in all regions on January 7, January 12, January 16, January 13, January 10, January 17, January 10, January 18 and January 14, respectively. Major vaccine interventions have been effective in reducing transmission in the nine areas of England given the mortality rate of the infected people and epidemiological characteristics of SARS-CoV-2. We also found that vaccination among people aged 70 to 80 had made a significant contribution to reducing transmission of the virus. The model can be extended to forecast the effects of certain interventions in public health emergencies, the effect of preventing the spread of disease, and the effect of different interventions in different age groups to find the best way to control the spread of disease. It can also be extended to drug and non-drug interventions to find the best combination of solutions.

scholarly journals Social contact patterns among employees in 3 U.S. companies during early phases of the COVID-19 pandemic, April to June 2020

2020 ◽  
Author(s):  
Moses C. Kiti ◽  
Obianuju G. Aguolu ◽  
Carol Y. Liu ◽  
Ana R. Mesa ◽  
Rachel Regina ◽  
...  
Keyword(s):  
Race And Ethnicity ◽  
Control Strategies ◽  
Age Groups ◽  
Social Contact ◽  
The United States ◽  
Median Number ◽  
Cross Sectional ◽  
Contact Patterns ◽  
The Uk ◽  
Spread Of Infection

2.AbstractImportanceDevising control strategies against diseases such as COVID-19 require understanding of contextual social mixing and contact patterns. There has been no standardized multi-site social contact study conducted in workplace settings in the United States that can be used to broadly inform pandemic preparedness policy in these settings.ObjectiveThe study aimed to characterize the patterns of social contacts and mixing across workplace environments, including on-site or when teleworking.DesignThis was a cross-sectional non-probability survey that used standardized social contact diaries to collect data. Employees were requested to record their physical and non-physical contacts in a diary over two consecutive days, documented at the end of each day. Employees from each company were enrolled through email and electronic diaries sent as individual links. Data were collected from April to June 2020.SettingTwo multinational consulting companies and one university administrative department, all located in Georgia, USA.ParticipantsEmployees opted into the study by accepting the invitation on a link sent via email.Main OutcomeThe outcome was median number of contacts per person per day. This was stratified by day of data collection, age, sex, race and ethnicity.ResultsOf 3,835 employees approached, 357 (9.3%) completed the first day of contact diary of which 304 completed both days of contact diary. There was a median of 2 contacts (IQR: 1-4, range: 0-21) per respondent on both day one and two. The majority (55%) of contacts involved conversation only, occurred at home (64%), and cumulatively lasted more than 4 hours (38%). Most contacts were repeated, and within same age groups, though participants aged 30-59 years reported substantial inter-generational mixing with children.ConclusionParticipating employees in 3 surveyed workplaces reported few contacts, similar to studies from the UK and China when shelter-in-place orders were in effect during the pandemic. Many contacts were repeated which may limit the spread of infection. Future rounds are planned to assess changes in contact patterns when employees resume work in the office after the lockdown due to COVID-19 pandemic.

scholarly journals The differential impact of physical distancing strategies on social contacts relevant for the spread of COVID-19: Evidence from a multi-country survey

2020 ◽  
Author(s):  
Emanuele Del Fava ◽  
Jorge Cimentada ◽  
Daniela Perrotta ◽  
André Grow ◽  
Francesco Rampazzo ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Age Groups ◽  
Social Contact ◽  
The United States ◽  
Social Contacts ◽  
Contact Patterns ◽  
The Uk ◽  
Facebook Advertising ◽  
Net Reproduction ◽  
The Impact

AbstractPhysical distancing measures are intended to mitigate the spread of COVID-19, even though their impact on social contacts and disease transmission remains unclear. Obtaining timely data on social contact patterns can help to assess the impact of such protective measures. We conducted an online opt-in survey based on targeted Facebook advertising campaigns across seven European countries (Belgium, France, Germany, Italy, Netherlands, Spain, United Kingdom (UK)) and the United States (US), achieving a sample of 53,708 questionnaires in the period March 13–April 13, 2020. Post-stratification weights were produced to correct for biases. Data on social contact numbers, as well as on protective behaviour and perceived level of threat were collected and used to the expected net reproduction number by week, Rt, with respect to pre-pandemic data. Compared to social contacts reported prior to COVID-19, in mid-April daily social contact numbers had decreased between 49% in Germany and 83% in Italy, ranging from below three contacts per day in France, Spain, and the UK up to four in Germany and the Netherlands. Such reductions were sufficient to bring Rt to one or even below in all countries, except Germany. Evidence from the US and the UK showed that the number of daily social contacts mainly decreased after governments issued the first physical distancing guidelines. Finally, although contact numbers decreased uniformly across age groups, older adults reported the lowest numbers of contacts, indicating higher levels of protection. We provided a comparable set of statistics on social contact patterns during the COVID-19 pandemic for eight high-income countries, disaggregated by week. As these estimates offer a more grounded alternative to the theoretical assumptions often used in epidemiological models, the scientific community could draw on this information for developing more realistic epidemic models of COVID-19.

scholarly journals Implementation Strategies for Improving Vitamin D Status and Increasing Vitamin D Intake in the UK: Current Controversies and Future Perspectives. Proceedings of the 2nd Rank Prize Funds Forum on Vitamin D

2021 ◽  
pp. 1-60
Author(s):  
J.L. Buttriss ◽  
S.A. Lanham-New ◽  
S. Steenson ◽  
L. Levy ◽  
G.E. Swan ◽  
...  
Keyword(s):  
Vitamin D ◽  
Age Groups ◽  
Implementation Strategies ◽  
Vitamin D Status ◽  
Cost Information ◽  
Hydroxyvitamin D ◽  
Minority Ethnic Groups ◽  
Modelling Studies ◽  
Clinical Consequences ◽  
The Uk

Abstract A multi-disciplinary expert group met to discuss vitamin D deficiency in the UK, and strategies for improving population intakes and status. Changes to UK Government advice since the 1st Rank Forum on Vitamin D (2009) were discussed, including rationale for setting a RNI (10µg/day;400IU/day) for adults and children (4+ years). Current UK data show inadequate intakes among all age groups, and high prevalence of low vitamin D status among specific groups (e.g. pregnant women and adolescent males/females). Evidence of widespread deficiency within some minority ethnic groups, resulting in nutritional rickets (particularly among Black and South Asian infants), raised particular concern. It is too early to establish whether population vitamin D status has altered since Government recommendations changed in 2016. Vitamin D food fortification was discussed as a potential strategy to increase population intakes. Data from dose-response and dietary modelling studies indicate dairy products, bread, hens’ eggs and some meats as potential fortification vehicles. Vitamin D3 appears more effective than vitamin D2 for raising serum 25-hydroxyvitamin D concentration, which has implications for choice of fortificant. Other considerations for successful fortification strategies include: i) need for ‘real-world’ cost information for use in modelling work; ii) supportive food legislation; iii) improved consumer and health professional understanding of vitamin D’s importance; iv) clinical consequences of inadequate vitamin D status; v) consistent communication of Government advice across health/social care professions, and via the food industry. These areas urgently require further research to enable universal improvement in vitamin D intakes and status in the UK population.

scholarly journals One Year of the COVID-19 Pandemic in Galicia: A Global View of Age-Group Statistics during Three Waves

2021 ◽  
Vol 18 (10) ◽  
pp. 5104
Author(s):  
Iván Area ◽  
Henrique Lorenzo ◽  
Pedro J. Marcos ◽  
Juan J. Nieto
Keyword(s):  
Intensive Care Unit ◽  
Hospital Admissions ◽  
Age Groups ◽  
Age Group ◽  
Nw Spain ◽  
The Past ◽  
Global View ◽  
Time Period ◽  
Key Variables ◽  
One Year

In this work we look at the past in order to analyze four key variables after one year of the COVID-19 pandemic in Galicia (NW Spain): new infected, hospital admissions, intensive care unit admissions and deceased. The analysis is presented by age group, comparing at each stage the percentage of the corresponding group with its representation in the society. The time period analyzed covers 1 March 2020 to 1 April 2021, and includes the influence of the B.1.1.7 lineage of COVID-19 which in April 2021 was behind 90% of new cases in Galicia. It is numerically shown how the pandemic affects the age groups 80+, 70+ and 60+, and therefore we give information about how the vaccination process could be scheduled and hints at why the pandemic had different effects in different territories.

scholarly journals Human Astrovirus Outbreak in a Daycare Center and Propagation among Household Contacts

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1100
Author(s):  
Ignacio Parrón ◽  
Elsa Plasencia ◽  
Thais Cornejo-Sánchez ◽  
Mireia Jané ◽  
Cristina Pérez ◽  
...  
Keyword(s):  
Acute Gastroenteritis ◽  
Age Groups ◽  
Rt Pcr ◽  
Daycare Center ◽  
Infected People ◽  
Conditioning Factors ◽  
Household Contacts ◽  
Human Astrovirus ◽  
Asymptomatic Infections ◽  
Clinical Cases

We investigated an outbreak of acute gastroenteritis due to human astrovirus in a daycare center, describing the transmission mechanism, the most affected age groups, conditioning factors and the extent of the outbreak among household contacts of the daycare center attenders. Data were collected from persons exposed at the daycare center and their home contacts. Fecal samples from affected and non-affected daycare center attenders were analyzed for viruses causing acute gastroenteritis by RT-PCR. The percentage of households affected and the attack rates (AR) were calculated. The attack rates were compared using the rate ratio (RR) with 95% confidence intervals. Information was obtained from 245 people (76 attenders and 169 contacts) of whom 49 were clinical cases. Five HAstV-4, two HAstV-8 and three non-typable HAstV cases were identified (six from clinical cases and four from asymptomatic infected people). The global AR was 20% (41.2% in children aged < 2 years). Data were obtained from 67 households: 20 households of affected attenders and 47 of non-affected attendees. Household contacts of affected attenders had a higher AR (74.3%) than that of non-affected attendees (2.4%). We found asymptomatic infections amongst daycare attendees. The transmission of HAstV during the outbreak was not limited to the daycare center but extended to household contacts of both affected and non-affected attenders.

How left behind are rural parents of migrant children? Evidence from Thailand

2010 ◽  
Vol 30 (5) ◽  
pp. 811-841 ◽  
Author(s):  
JOHN KNODEL ◽  
JIRAPORN KESPICHAYAWATTANA ◽  
CHANPEN SAENGTIENCHAI ◽  
SUVINEE WIWATWANICH
Keyword(s):  
Adult Children ◽  
Rural Areas ◽  
Living Arrangements ◽  
Urban Areas ◽  
Extended Family ◽  
Age Groups ◽  
Social Contact ◽  
Migrant Children ◽  
Older Parents ◽  
Economic Changes

ABSTRACTThe consequences of adult children's migration from rural areas for older parents who remain behind are keenly debated. While the mass media and international advocacy organisations favour an ‘alarmist’ view of desertion, the academic literature makes more sanguine assessments using the ‘household strategy’ and ‘modified extended family’ perspectives. We examine the relationship between the migration of adult children and various dimensions of older parents' wellbeing in Thailand using evidence from a survey that focused on the issues. The results provide little support for the alarmist view, but instead suggest that parents and adult children adapt to the social and economic changes associated with development in ways not necessarily detrimental to intergenerational relations. The migration of children, especially to urban areas, often benefits parents' material support while the recent spread of cell phones has radically increased their ability to maintain social contact. Nevertheless, changing living arrangements through increased migration and the smaller family sizes of the youngest age groups of older people pose serious challenges for aspects of filial support, especially at advanced ages when chronic illness and frailty require long-term personal care. Dealing with this emerging situation in a context of social, economic and technological change is among the most critical issues facing those concerned with the implications of rapid population ageing in Thailand and elsewhere.

Variation of cardiac magnetic resonance radiomics features by age and sex in healthy participants from the UK Biobank

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
Z Raisi-Estabragh ◽  
A Jaggi ◽  
N Aung ◽  
S Neubauer ◽  
S Piechnik ◽  
...  
Keyword(s):  
Risk Factors ◽  
Cardiac Magnetic Resonance ◽  
Age Groups ◽  
Texture Features ◽  
Funding Source ◽  
Uk Biobank ◽  
Men And Women ◽  
The Uk ◽  
Age And Sex ◽  
Apparently Healthy

Abstract Introduction Cardiac magnetic resonance (CMR) radiomics use voxel-level data to derive quantitative indices of myocardial tissue texture, which may provide complementary risk information to traditional CMR measures. Purpose In this first stage of our work, establishing the performance characteristics of CMR radiomics in relation to disease outcomes, we aimed to elucidate differences in radiomic features by sex and age in apparently healthy adults. Methods We defined a healthy cohort from the first 5,065 individuals completing the UK Biobank Imaging Enhancement, limiting to white Caucasian ethnicity, and excluding those with major co-morbidities, or cardiovascular risk factors/symptoms. We created evenly distributed age groups: 45–54 years, 55–64 years, 65–74 years. Radiomics features were extracted from left ventricle segmentations, with normalisation to body surface area. We compared mean values of individual features between the sexes, stratified by age and separately between the oldest and youngest age groups for each sex. Results We studied 657 (309 men, 358 women) healthy individuals. There were significant differences between radiomics features of men and women. Different features appeared more important at different age groups. For instance, in the youngest age group “end-systolic coarseness” showed greatest difference between men and women, whilst “end-diastolic run percentage” and “end-diastolic high grey level emphasis” showed most variation in the oldest and middle age groups. In the oldest age groups, differences between men and women were most predominant in the texture features, whilst in the younger groups a mixture of shape and texture differences were observed. We demonstrate significant variation between radiomics features by age, these differences are exclusively in texture features with different features implicated in men and women (“end-diastolic mean intensity” in women, “end-systolic sum entropy in men”). Conclusions There are significant age and sex differences in CMR radiomics features of apparently healthy adults, demonstrating alterations in myocardial architecture not appreciated by conventional indices. In younger ages, shape and texture differences are observed, whilst in older ages texture differences dominate. Furthermore, texture features are the most different features between the youngest and oldest hearts. We provide proof-of-concept data indicating CMR radiomics has discriminatory value with regard to two characteristics strongly linked to cardiovascular outcomes. We will next elucidate relationships between CMR radiomics, cardiac risk factors, and clinical outcomes, establishing predictive value incremental to existing measures. Funding Acknowledgement Type of funding source: Other. Main funding source(s): European Union's Horizon 2020 research and innovation programme (825903),British Heart Foundation Clinical Research Training Fellowship (FS/17/81/33318)

TIME SERIES MODELLING OF EPIDEMICS: LEADING INDICATORS, CONTROL GROUPS AND POLICY ASSESSMENT

2021 ◽  
Vol 257 ◽  
pp. 83-100
Author(s):  
Andrew Harvey
Keyword(s):  
Time Series ◽  
Data Science ◽  
Leading Indicators ◽  
Control Groups ◽  
Balanced Growth ◽  
Time Series Modelling ◽  
Key Variables ◽  
The Uk ◽  
The Relationship

This article shows how new time series models can be used to track the progress of an epidemic, forecast key variables and evaluate the effects of policies. The univariate framework of Harvey and Kattuman (2020, Harvard Data Science Review, Special Issue 1—COVID-19, https://hdsr.mitpress.mit.edu/pub/ozgjx0yn) is extended to model the relationship between two or more series and the role of common trends is discussed. Data on daily deaths from COVID-19 in Italy and the UK provides an example of leading indicators when there is a balanced growth. When growth is not balanced, the model can be extended by including a non-stationary component in one of the series. The viability of this model is investigated by examining the relationship between new cases and deaths in the Florida second wave of summer 2020. The balanced growth framework is then used as the basis for policy evaluation by showing how some variables can serve as control groups for a target variable. This approach is used to investigate the consequences of Sweden’s soft lockdown coronavirus policy in the spring of 2020.

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