scholarly journals Cohort-based Smoothing Methods for Age-specific Contact Rates

2018 ◽  
Author(s):  
Yannick Vandendijck ◽  
Carlo G. Camarda ◽  
Niel Hens
Keyword(s):  
Disease Transmission ◽  
Age Distribution ◽  
Social Contact ◽  
Population Based ◽  
Smoothing Methods ◽  
Transmission Parameters ◽  
Contact Rates ◽  
The Social ◽  
Specific Contact ◽  
Contact Data

AbstractThe use of social contact rates is widespread in infectious disease modelling, since it is known that they provide proxies of crucial determinants of epidemiological and disease transmission parameters. Information on social contact rates can, for example, be obtained from a population-based contact diary survey, such as the POLYMOD study. Estimation of age-specific contact rates from these studies is often done using bivariate smoothing techniques. Typically, smoothing is done in the dimensions of the respondent’s and contact’s age. In this paper, we introduce a smoothing constrained approach - taking into account the reciprocal nature of contacts - where the contact rates are assumed smooth from a cohort perspective as well as from the age distribution of contacts. This is achieved by smoothing over the diagonal components (including all subdiagonals) of the social contact matrix. This approach is supported by the fact that people age with time and thus contact rates should vary smoothly by cohorts. Two approaches that allow for smoothing of social contact data over cohorts are proposed: (1) reordening of the diagonal components of the social contact rate matrix; and (2) reordening of the penalty matrix associated with the diagonal components. Parameter estimation is done using constrained penalized iterative reweighted least squares. A simulation study is presented to compare methods. The proposed methods are illustrated on the Belgian POLYMOD data of 2006.

scholarly journals Place-based social contact and mixing: a typology of generic meeting places of relevance for infectious disease transmission

2017 ◽  
Vol 145 (12) ◽  
pp. 2582-2593 ◽  
Author(s):  
M. STRÖMGREN ◽  
E. HOLM ◽  
Ö. DAHLSTRÖM ◽  
J. EKBERG ◽  
H. ERIKSSON ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Disease Transmission ◽  
Social Contact ◽  
Physical Contact ◽  
Transmission Risk ◽  
Geographical Differences ◽  
Infectious Disease Transmission ◽  
Swedish Population ◽  
The Social ◽  
The Family

SUMMARYThis study aims to develop a typology of generic meeting places based on social contact and mixing of relevance for infectious disease transmission. Data were collected by means of a contact diary survey conducted on a representative sample of the Swedish population. The typology is derived from a cluster analysis accounting for four dimensions associated with transmission risk: visit propensity and its characteristics in terms of duration, number of other persons present and likelihood of physical contact. In the analysis, we also study demographic, socio-economic and geographical differences in the propensity of visiting meeting places. The typology identifies the family venue, the fixed activity site, the family vehicle, the trading plaza and the social network hub as generic meeting places. The meeting place typology represents a spatially explicit account of social contact and mixing relevant to infectious disease modelling, where the social context of the outbreak can be highlighted in light of the actual infectious disease.

scholarly journals Predicting the SARS-CoV-2 effective reproduction number using bulk contact data from mobile phones

2021 ◽  
Vol 118 (31) ◽  
pp. e2026731118
Author(s):  
Sten Rüdiger ◽  
Stefan Konigorski ◽  
Alexander Rakowski ◽  
Jonathan Antonio Edelman ◽  
Detlef Zernick ◽  
...  
Keyword(s):  
Reproduction Number ◽  
Gps Tracking ◽  
Contact Behavior ◽  
Social Distancing ◽  
The Social ◽  
Global Positioning ◽  
Specific Contact ◽  
Contact Data ◽  
Nonpharmaceutical Interventions

Over the last months, cases of SARS-CoV-2 surged repeatedly in many countries but could often be controlled with nonpharmaceutical interventions including social distancing. We analyzed deidentified Global Positioning System (GPS) tracking data from 1.15 to 1.4 million cell phones in Germany per day between March and November 2020 to identify encounters between individuals and statistically evaluate contact behavior. Using graph sampling theory, we estimated the contact index (CX), a metric for number and heterogeneity of contacts. We found that CX, and not the total number of contacts, is an accurate predictor for the effective reproduction number R derived from case numbers. A high correlation between CX and R recorded more than 2 wk later allows assessment of social behavior well before changes in case numbers become detectable. By construction, the CX quantifies the role of superspreading and permits assigning risks to specific contact behavior. We provide a critical CX value beyond which R is expected to rise above 1 and propose to use that value to leverage the social-distancing interventions for the coming months.

scholarly journals Graph, Spectra, Control and Epidemics: An Example with a SEIR Model

Mathematics ◽  
2021 ◽  
Vol 9 (22) ◽  
pp. 2987
Author(s):  
Giacomo Aletti ◽  
Alessandro Benfenati ◽  
Giovanni Naldi
Keyword(s):  
Social Contact ◽  
Economic Cost ◽  
Population Based ◽  
Biological Data ◽  
Contact Network ◽  
Graph Spectra ◽  
Animal Populations ◽  
The Social ◽  
Spread Of Infection ◽  
Group Version

Networks and graphs offer a suitable and powerful framework for studying the spread of infection in human and animal populations. In the case of a heterogeneous population, the social contact network has a pivotal role in the analysis of directly transmitted infectious diseases. The literature presents several works where network-based models encompass realistic features (such as contacts networks or host–pathogen biological data), but analytical results are nonetheless scarce. As a significant example, in this paper, we develop a multi-group version of the epidemiological SEIR population-based model. Each group can represent a social subpopulation with the same habits or a group of geographically localized people. We consider also heterogeneity in the weighting of contacts between two groups. As a simple application, we propose a simple control algorithm in which we optimize the connection weights in order to minimize the combination between an economic cost and a social cost. Some numerical simulations are also provided.

scholarly journals Combining fine-scale social contact data with epidemic modelling reveals interactions between contact tracing, quarantine, testing and physical distancing for controlling COVID-19

2020 ◽  
Author(s):  
Josh A. Firth ◽  
Joel Hellewell ◽  
Petra Klepac ◽  
Stephen Kissler ◽  
Adam J. Kucharski ◽  
...  
Keyword(s):  
Real World ◽  
Social Dynamics ◽  
Control Strategies ◽  
Single Point ◽  
Local Population ◽  
Social Contact ◽  
Contact Tracing ◽  
Contact Rates ◽  
Contact Data ◽  
Potential Impact

AbstractCase isolation and contact tracing can contribute to the control of COVID-19 outbreaks1,2. However, it remains unclear how real-world networks could influence the effectiveness and efficiency of such approaches. To address this issue, we simulated control strategies for SARS-CoV-2 in a real-world social network generated from high resolution GPS data3,4. We found that tracing contacts-of-contacts reduced the size of simulated outbreaks more than tracing of only contacts, but resulted in almost half of the local population being quarantined at a single point in time. Testing and releasing non-infectious individuals led to increases in outbreak size, suggesting that contact tracing and quarantine may be most effective when it acts as a ‘local lockdown’ when contact rates are high. Finally, we estimated that combining physical distancing with contact tracing could enable epidemic control while reducing the number of quarantined individuals. Our approach highlights the importance of network structure and social dynamics in evaluating the potential impact of SARS-CoV-2 control.

scholarly journals Temporal variation of human encounters and the number of locations in which they occur: a longitudinal study of Hong Kong residents

2018 ◽  
Vol 15 (138) ◽  
pp. 20170838 ◽  
Author(s):  
Kin On Kwok ◽  
Ben Cowling ◽  
Vivian Wei ◽  
Steven Riley ◽  
Jonathan M. Read
Keyword(s):  
Hong Kong ◽  
Longitudinal Study ◽  
Individual Variation ◽  
Total Duration ◽  
Social Contact ◽  
Cross Sectional ◽  
Individual Level ◽  
Contact Rates ◽  
The Social ◽  
Population Scale

Patterns of social contact between individuals are important for the transmission of many pathogens and shaping patterns of immunity at the population scale. To refine our understanding of how human social behaviour may change over time, we conducted a longitudinal study of Hong Kong residents. We recorded the social contact patterns for 1450 individuals, up to four times each between May 2012 and September 2013. We found individuals made contact with an average of 12.5 people within 2.9 geographical locations, and spent an average estimated total duration of 9.1 h in contact with others during a day. Distributions of the number of contacts and locations in which contacts were made were not significantly different between study waves. Encounters were assortative by age, and the age mixing pattern was broadly consistent across study waves. Fitting regression models, we examined the association of contact rates (number of contacts, total duration of contact, number of locations) with covariates and calculated the inter- and intra-participant variation in contact rates. Participant age was significantly associated with the number of contacts made, the total duration of contact and the number of locations in which contact occurred, with children and parental-age adults having the highest rates of contact. The number of contacts and contact duration increased with the number of contact locations. Intra-individual variation in contact rate was consistently greater than inter-individual variation. Despite substantial individual-level variation, remarkable consistency was observed in contact mixing at the population scale. This suggests that aggregate measures of mixing behaviour derived from cross-sectional information may be appropriate for population-scale modelling purposes, and that if more detailed models of social interactions are required for improved public health modelling, further studies are needed to understand the social processes driving intra-individual variation.

scholarly journals COVID-19 Contact Tracing in an Overseas U.S. Military Population

2021 ◽  
Author(s):  
Cynthia S Sikorski ◽  
Misty D Scheel ◽  
Stephanie M Harris ◽  
Julia A Nefczyk
Keyword(s):  
Public Health ◽  
Disease Transmission ◽  
Age Distribution ◽  
Health Department ◽  
Population Based ◽  
Contact Tracing ◽  
Public Health Department ◽  
Site Testing ◽  
Medical Provider ◽  
Military Population

ABSTRACT The purpose of this study was to describe the early epidemiology and contact tracing challenges for Covid-19 infection in an overseas military and DoD population. From February 28, 2020 to April 27, 2020, patients who were diagnosed with Covid-19 infection completed a Centers for Disease Control Persons Under Investigation (PUI) form during their encounter with a medical provider. Positive results were forwarded to the Public Health Department. The results of the contact tracing and PUI form were entered into a database and analyzed. Eight Covid-19 cases were diagnosed in this overseas population. Based on beneficiary population, the cumulative incidence was ∼80/100,000 persons. The age distribution ranged from 25 to 60 years, median 36 years. Most patients were male (75%). More infection occurred in those living off base in the community (87.5%). With the capability of on-site testing at the hospital, the median duration from symptom onset to diagnosis improved from 5 days to 1 day. Disease contact tracing for DoD populations presents unique considerations in an overseas location. Public Health guidelines for the USA may have varying relevance in an overseas location. Rapid case identification with on-site testing is critical to disrupt disease transmission. Preventive measures for Covid-19 infection have decreased incidence of influenza-like illness.

scholarly journals Inferring age-specific differences in susceptibility to and infectiousness upon SARS-CoV-2 infection based on Belgian social contact data

2021 ◽  
Author(s):  
Nicolas Franco ◽  
Pietro Coletti ◽  
Lander Willem ◽  
Leonardo Angeli ◽  
Adrien Lajot ◽  
...  
Keyword(s):  
Vaccination Campaign ◽  
Real Life ◽  
Social Contact ◽  
The Elderly ◽  
Computational Tools ◽  
Incidence Data ◽  
Transmission Parameters ◽  
Very Young Children ◽  
Age Related ◽  
Contact Data

Several important aspects related to SARS-CoV-2 transmission are not well known due to a lack of appropriate data. However, mathematical and computational tools can be used to extract part of this information from the available data, like some hidden age-related characteristics. In this paper, we investigate age-specific differences in susceptibility to and infectiousness upon contracting SARS-CoV-2 infection. More specifically, we use panel-based social contact data from diary-based surveys conducted in Belgium combined with the next generation principle to infer the relative incidence and we compare this to real-life incidence data. Comparing these two allows for the estimation of age-specific transmission parameters. Our analysis implies the susceptibility in children to be around half of the susceptibility in adults, and even lower for very young children (preschooler). However, the probability of adults and the elderly to contract the infection is decreasing throughout the vaccination campaign, thereby modifying the picture over time.

scholarly journals Quantifying social contact patterns in Minnesota during Stay-at-Home social distancing order

2021 ◽  
Author(s):  
Audrey M Dorelien ◽  
Narmada Venkateswaran ◽  
Jiuchen Deng ◽  
Kelly Searle ◽  
Eva Enns ◽  
...  
Keyword(s):  
Negative Binomial ◽  
Social Contact ◽  
Negative Binomial Regression ◽  
Risk Groups ◽  
Social Distancing ◽  
Contact Patterns ◽  
Specific Contact ◽  
Contact Data ◽  
Age Structured ◽  
At Home

SARS-CoV-2 is primarily transmitted through person-to-person contacts. It is important to collect information on age-specific contact patterns because SARS-CoV-2 susceptibility, transmission, and morbidity vary by age. To reduce risk of infection, social distancing measures have been implemented. Social contact data, which identify who has contact with whom especially by age and place are needed to identify high-risk groups and serve to inform the design of non-pharmaceutical interventions. We estimated and used negative binomial regression to compare the number of daily contacts during the first wave (April-May 2020) of the Minnesota Social Contact Study, based on respondents age, gender, race/ethnicity, region, and other demographic characteristics. We used information on age and location of contacts to generate age-structured contact matrices. Finally, we compared the age-structured contact matrices during the stay-at-home order to pre-pandemic matrices. During the state-wide stay-home order, the mean daily number of contacts was 5.6. We found significant variation in contacts by age, gender, race, and region. Adults between 40 and 50 years had the highest number of contacts. Respondents in Black households had 2.1 more contacts than respondent in White households, while respondents in Asian or Pacific Islander households had approximately the same number of contacts as respondent in White households. Respondents in Hispanic households had approximately two fewer contacts compared to White households. Most contacts were with other individuals in the same age group. Compared to the pre-pandemic period, the biggest declines occurred in contacts between children, and contacts between those over 60 with those below 60.

scholarly journals Forecasting the SARS-CoV-2 effective reproduction number using bulk contact data from mobile phones

2020 ◽  
Author(s):  
Sten Rüdiger ◽  
Stefan Konigorski ◽  
Jonathan Edelman ◽  
Detlef Zernick ◽  
Alexander Thieme ◽  
...  
Keyword(s):  
Large Scale ◽  
Reproduction Number ◽  
Gps Tracking ◽  
Contact Behavior ◽  
Social Distancing ◽  
The Social ◽  
Specific Contact ◽  
Contact Data ◽  
Pharmaceutical Interventions

Over the last months, cases of SARS-CoV-2 surged repeatedly in many countries and could often be controlled with non-pharmaceutical interventions such as social distancing. We analyzed de-identified GPS tracking data from 1.15 to 1.4 million cell phones in Germany per day between March-November 2020 to identify encounters between individuals and statistically evaluate large-scale contact behavior. Using graph sampling theory we estimated the contact index (CI), a metric for number and heterogeneity of contacts and found that the contact index, and not the total number of contacts, is an accurate predsictor for the effective reproduction number R. A high correlation between CI and R occurring more than two weeks later allows timely assessment of the social behavior well before the infections become detectable. The CI quantifies the role of superspreading and allows assigning risks to specific contact behavior. We provide a critical CI-value beyond which R is expected to rise above 1 and propose to use it to leverage the social distancing interventions for the coming months.

scholarly journals A modified age-structured SIR model for COVID-19 type viruses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vishaal Ram ◽  
Laura P. Schaposnik
Keyword(s):  
Mortality Rate ◽  
Age Distribution ◽  
Social Contact ◽  
Sir Model ◽  
Disease Spread ◽  
Population Parameters ◽  
Specific Contact ◽  
Treatment Measures ◽  
Age Structured ◽  
Varying Population

AbstractWe present a modified age-structured SIR model based on known patterns of social contact and distancing measures within Washington, USA. We find that population age-distribution has a significant effect on disease spread and mortality rate, and contribute to the efficacy of age-specific contact and treatment measures. We consider the effect of relaxing restrictions across less vulnerable age-brackets, comparing results across selected groups of varying population parameters. Moreover, we analyze the mitigating effects of vaccinations and examine the effectiveness of age-targeted distributions. Lastly, we explore how our model can applied to other states to reflect social-distancing policy based on different parameters and metrics.

Sign in / Sign up

Export Citation Format

Share Document