scholarly journals Two-Age-Structured COVID-19 Epidemic Model: Estimation of Virulence Parameters to Interpret Effects of National and Regional Feedback Interventions and Vaccination

Mathematics ◽  
2021 ◽  
Vol 9 (19) ◽  
pp. 2414
Author(s):  
Cristiano Maria Verrelli ◽  
Fabio Della Rossa
Keyword(s):  
Compartmental Model ◽  
Transmission Rate ◽  
National Level ◽  
Real Data ◽  
Social Contacts ◽  
The Social ◽  
Age Dependent ◽  
Feedback Interventions ◽  
Age Structured ◽  
Prioritization Strategy

The COVID-19 epidemic has recently led in Italy to the implementation of different external strategies in order to limit the spread of the disease in response to its transmission rate: strict national lockdown rules, followed first by a weakening of the social distancing and contact reduction feedback interventions and finally the implementation of coordinated intermittent regional actions, up to the application, in this last context, of an age-stratified vaccine prioritization strategy. This paper originally aims at identifying, starting from the available age-structured real data at the national level during the specific aforementioned scenarios, external-scenario-dependent sets of virulence parameters for a two-age-structured COVID-19 epidemic compartmental model, in order to provide an interpretation of how each external scenario modifies the age-dependent patterns of social contacts and the spread of COVID-19.

scholarly journals Unreported cases for Age Dependent COVID-19 Outbreak in Japan

2020 ◽  
Author(s):  
Quentin Griette ◽  
Pierre Magal ◽  
Ousmane Seydi
Keyword(s):  
Mathematical Model ◽  
Age Structure ◽  
Early Stage ◽  
Structured Data ◽  
Computational Method ◽  
Mitigation Measures ◽  
Age Classes ◽  
The Social ◽  
Age Dependent ◽  
Age Structured

AbstractWe investigate the age structured data for the COVID-19 outbreak in Japan. We consider a mathematical model for the epidemic with unreported infectious patient with and without age structure. In particular, we build a new mathematical model and a new computational method to fit the data by using age classes dependent exponential growth at the early stage of the epidemic. This allows to take into account differences in the response of patients to the disease according to their age. This model also allows for a heterogeneous response of the population to the social distancing measures taken by the local government. We fit this model to the observed data and obtain a snapshot of the effective transmissions occurring inside the population at different times, which indicates where and among whom the disease propagates after the start of public mitigation measures.

scholarly journals Stochastic simulation of successive waves of COVID-19 in the province of Barcelona

2021 ◽  
Author(s):  
M. Bosman ◽  
A. Esteve ◽  
L. Gabbanelli ◽  
X. Jordan ◽  
A. López-Gay ◽  
...  
Keyword(s):  
Compartmental Model ◽  
Stochastic Approach ◽  
Mitigation Strategies ◽  
Time Dependent ◽  
Population Census ◽  
Mathematical Epidemiology ◽  
The Social ◽  
Age Dependent ◽  
Dynamical Features ◽  
The Impact

AbstractAnalytic compartmental models are currently used in mathematical epidemiology to forecast the COVID-19 pandemic evolution and explore the impact of mitigation strategies. In general, such models treat the population as a single entity, losing the social, cultural and economical specifici- ties. We present a network model that uses socio-demographic datasets with the highest available granularity to predict the spread of COVID-19 in the province of Barcelona. The model is flexible enough to incorporate the effect of containment policies, such as lockdowns or the use of protec- tive masks, and can be easily adapted to future epidemics. We follow a stochastic approach that combines a compartmental model with detailed individual microdata from the population census, including social determinants and age-dependent strata, and time-dependent mobility information. We show that our model reproduces the dynamical features of the disease across two waves and demonstrate its capability to become a powerful tool for simulating epidemic events.

scholarly journals Unreported Cases for Age Dependent COVID-19 Outbreak in Japan

Biology ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 132 ◽  
Author(s):  
Quentin Griette ◽  
Pierre Magal ◽  
Ousmane Seydi
Keyword(s):  
Mathematical Model ◽  
Age Structure ◽  
Early Stage ◽  
Structured Data ◽  
Computational Method ◽  
Mitigation Measures ◽  
Age Classes ◽  
The Social ◽  
Age Dependent ◽  
Age Structured

We investigate the age structured data for the COVID-19 outbreak in Japan. We consider a mathematical model for the epidemic with unreported infectious patient with and without age structure. In particular, we build a new mathematical model and a new computational method to fit the data by using age classes dependent exponential growth at the early stage of the epidemic. This allows to take into account differences in the response of patients to the disease according to their age. This model also allows for a heterogeneous response of the population to the social distancing measures taken by the local government. We fit this model to the observed data and obtain a snapshot of the effective transmissions occurring inside the population at different times, which indicates where and among whom the disease propagates after the start of public mitigation measures.

scholarly journals Modeling the early phase of the Belgian COVID-19 epidemic using a stochastic compartmental model and studying its implied future trajectories

2020 ◽  
Author(s):  
Steven Abrams ◽  
James Wambua ◽  
Eva Santermans ◽  
Lander Willem ◽  
Elise Kuylen ◽  
...  
Keyword(s):  
Compartmental Model ◽  
Large Fraction ◽  
Social Contacts ◽  
Admission Data ◽  
The Future ◽  
Belgian Population ◽  
Age Structured ◽  
The Impact ◽  
Global Population ◽  
Mcmc Approach

AbstractFollowing the onset of the ongoing COVID-19 pandemic throughout the world, a large fraction of the global population is or has been under strict measures of physical distancing and quarantine, with many countries being in partial or full lockdown. These measures are imposed in order to reduce the spread of the disease and to lift the pressure on healthcare systems. Estimating the impact of such interventions as well as monitoring the gradual relaxing of these stringent measures is quintessential to understand how resurgence of the COVID-19 epidemic can be controlled for in the future. In this paper we use a stochastic age-structured discrete time compartmental model to describe the transmission of COVID-19 in Belgium. Our model explicitly accounts for age-structure by integrating data on social contacts to (i) assess the impact of the lockdown as implemented on March 13, 2020 on the number of new hospitalizations in Belgium; (ii) conduct a scenario analysis estimating the impact of possible exit strategies on potential future COVID-19 waves. More specifically, the aforementioned model is fitted to hospital admission data, data on the daily number of COVID-19 deaths and serial serological survey data informing the (sero)prevalence of the disease in the population while relying on a Bayesian MCMC approach. Our age-structured stochastic model describes the observed outbreak data well, both in terms of hospitalizations as well as COVID-19 related deaths in the Belgian population. Despite an extensive exploration of various projections for the future course of the epidemic, based on the impact of adherence to measures of physical distancing and a potential increase in contacts as a result of the relaxation of the stringent lockdown measures, a lot of uncertainty remains about the evolution of the epidemic in the next months.

scholarly journals Dynamic quarantine: a comparative analysis of the Chilean public health response to COVID-19

2020 ◽  
Vol 148 ◽  
Author(s):  
Gonzalo Grebe ◽  
Javier A. Vélez ◽  
Anton Tiutiunnyk ◽  
Diego Aragón-Caqueo ◽  
Javier Fernández-Salinas ◽  
...  
Keyword(s):  
Public Health ◽  
Comparative Analysis ◽  
Transmission Rate ◽  
National Level ◽  
Metropolitan Region ◽  
Public Health Response ◽  
Country Level ◽  
Health Response ◽  
Primary Vector

Abstract In this study, an analysis of the Chilean public health response to mitigate the spread of COVID-19 is presented. The analysis is based on the daily transmission rate (DTR). The Chilean response has been based on dynamic quarantines, which are established, lifted or prolonged based on the percentage of infected individuals in the fundamental administrative sections, called communes. This analysis is performed at a national level, at the level of the Metropolitan Region (MR) and at the commune level in the MR according to whether the commune did or did not enter quarantine between late March and mid-May of 2020. The analysis shows a certain degree of efficacy in controlling the pandemic using the dynamic quarantine strategy. However, it also shows that apparent control has only been partially achieved to date. With this policy, the control of the DTR partially falls to 4%, where it settles, and the MR is the primary vector of infection at the country level. For this reason, we can conclude that the MR has not managed to control the disease, with variable results within its own territory.

scholarly journals Building Tag-Aware Groups for Music High-Order Ranking and Topic Discovery

2010 ◽  
Vol 1 (3) ◽  
pp. 1-18 ◽  
Author(s):  
Dimitrios Rafailidis ◽  
Alexandros Nanopoulos ◽  
Yannis Manolopoulos
Keyword(s):  
Real Data ◽  
Social Tagging ◽  
Topic Discovery ◽  
Retrieval Systems ◽  
The Social ◽  
Information Retrieval Systems ◽  
Aware Group ◽  
User Groups ◽  
Music Information ◽  
Ranking Analysis

In popular music information retrieval systems, users have the opportunity to tag musical objects to express their personal preferences, thus providing valuable insights about the formulation of user groups/communities. In this article, the authors focus on the analysis of social tagging data to reveal coherent groups characterized by their users, tags and music objects (e.g., songs and artists), which allows for the expression of discovered groups in a multi-aspect way. For each group, this study reveals the most prominent users, tags, and music objects using a generalization of the popular web-ranking concept in the social data domain. Experimenting with real data, the authors’ results show that each Tag-Aware group corresponds to a specific music topic, and additionally, a three way ranking analysis is performed inside each group. Building Tag-Aware groups is crucial to offer ways to add structure in the unstructured nature of tags.

scholarly journals Anthropological analysis on recent covid-19 infection in Italy

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
V A Sironi ◽  
M A Riva
Keyword(s):  
Medical Information ◽  
National Level ◽  
The Elderly ◽  
Point Of View ◽  
Cognitive Distortion ◽  
Psychological Reactions ◽  
Foreign Countries ◽  
The Social ◽  
Informative Role ◽  
Globalized World

Abstract The recent epidemic caused by the Covid-19 virus, which originated in China and then spread rapidly, can rightly be defined as the real 'first' epidemic in the social era. In an increasingly globalized world other recent epidemics (but more circumscribed, even if severely more lethal, such as Ebola and Sars) have been experienced with less media and emotional involvement, while the recent epidemic due to the new coronavirus has generated deserving reactions of analysis from an anthropological and social point of view, rather than on a health aspect. In Italy the epidemic event provoked sometimes excessive and irrational psychological reactions (from an unjustified panic to an irresponsible underestimation) and a cognitive distortion on anthropological level (wrong perspective perception of the pathological event). It has also generated disproportionate social repercussions at national level (refusal of stay for subjects coming from the lands in which diseased people are present) and at international level (foreclosure of landing of Italian tourists in some foreign countries). There was also incorrect medical information (confusion between infected - asymptomatic and/or non-hospitalized paucisymptomatic -, real patients with important symptoms - hospitalized - and sometimes in need of intensive care, subjects - the elderly and carriers of other serious diseases - died not for but with the Covid-19 infection) generated and amplified also by the pounding informative role of the mass media and by the news (often inaccurate and generating fake-news) spread in real time through social media. Key messages Irrational reactions must be avoided. Correct medical information are indispensable.

scholarly journals Age-dependent intra-specific competition in pre-adult life stages and its effects on adult population dynamics

2015 ◽  
Vol 27 (1) ◽  
pp. 131-156
Author(s):  
RONGSONG LIU ◽  
GERGELY RÖST ◽  
STEPHEN A. GOURLEY
Keyword(s):  
Disease Transmission ◽  
Adult Population ◽  
Adult Life ◽  
Life Stages ◽  
Larval Competition ◽  
Amphibian Species ◽  
Age Dependent ◽  
Age Structured ◽  
Delay Differential ◽  
Boundedness And Persistence

Intra-specific competition in insect and amphibian species is often experienced in completely different ways in their distinct life stages. Competition among larvae is important because it can impact on adult traits that affect disease transmission, yet mathematical models often ignore larval competition. We present two models of larval competition in the form of delay differential equations for the adult population derived from age-structured models that include larval competition. We present a simple prototype equation that models larval competition in a simplistic way. Recognising that individual larvae experience competition from other larvae at various stages of development, we then derive a more complex equation containing an integral with a kernel that quantifies the competitive effect of larvae of ageāon larvae of agea. In some parameter regimes, this model and the famous spruce budworm model have similar dynamics, with the possibility of multiple co-existing equilibria. Results on boundedness and persistence are also proved.

scholarly journals Cytomegalovirus seroepidemiology in an urban community of São Paulo, Brazil

2001 ◽  
Vol 35 (2) ◽  
pp. 124-129 ◽  
Author(s):  
LNB Almeida ◽  
RS Azevedo ◽  
M Amaku ◽  
E Massad
Keyword(s):  
Transmission Rate ◽  
Sao Paulo ◽  
Reproductive Age ◽  
Cluster Sampling ◽  
First Year ◽  
São Paulo ◽  
Cmv Infection ◽  
Force Of Infection ◽  
Age Dependent ◽  
First Year Of Life

INTRODUCTION: After the era of rubella vaccine, cytomegalovirus (CMV) infection is one of the most frequently causes of mental retardation and congenital deafness. Seroepidemiological studies are necessary to understand the transmission dynamics of the disease. The purpose of the study was to quantify the transmission rate of CMV disease in a community in the state of São Paulo, Brazil. METHODS: Using ELISA test (IgG), a retrospective serological survey looking for CMV antibodies was performed in an non-immunized community. Frozen sera from 443 individuals, randomly selected by cluster sampling technique in the town of Caieiras, São Paulo, were collected from November 1990 to January 1991. Seroprevalence was stratified by age (0-40 years). Mathematical techniques were applied to determine the age-dependent decay function of maternal antibodies during the first year of life, the age-dependent seroprevalence function and the force of infection for CMV in this community. RESULTS: It was observed a descending phase of seropositivity in the first 9 months, but changes in antibody titration were observed between 8 months old and one year of age. The average age of the first infection was 5.02 months of age and 19.84 years, when the age-dependent seroprevalence and the force of infection were analyzed between 10 months of age and 10 years of age and from 10 to 40 years old, respectively. CONCLUSION: CMV infection is highly prevalent among the population studied and infection occurs in the first year of life. This study shows that most women at reproductive age are vulnerable to the first infection, increasing the risk for congenital infection.

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