scholarly journals Projecting contact matrices in 177 geographical regions: An update and comparison with empirical data for the COVID-19 era

2021 ◽  
Vol 17 (7) ◽  
pp. e1009098
Author(s):  
Kiesha Prem ◽  
Kevin van Zandvoort ◽  
Petra Klepac ◽  
Rosalind M. Eggo ◽  
Nicholas G. Davies ◽  
...  

Mathematical models have played a key role in understanding the spread of directly-transmissible infectious diseases such as Coronavirus Disease 2019 (COVID-19), as well as the effectiveness of public health responses. As the risk of contracting directly-transmitted infections depends on who interacts with whom, mathematical models often use contact matrices to characterise the spread of infectious pathogens. These contact matrices are usually generated from diary-based contact surveys. However, the majority of places in the world do not have representative empirical contact studies, so synthetic contact matrices have been constructed using more widely available setting-specific survey data on household, school, classroom, and workplace composition combined with empirical data on contact patterns in Europe. In 2017, the largest set of synthetic contact matrices to date were published for 152 geographical locations. In this study, we update these matrices with the most recent data and extend our analysis to 177 geographical locations. Due to the observed geographic differences within countries, we also quantify contact patterns in rural and urban settings where data is available. Further, we compare both the 2017 and 2020 synthetic matrices to out-of-sample empirically-constructed contact matrices, and explore the effects of using both the empirical and synthetic contact matrices when modelling physical distancing interventions for the COVID-19 pandemic. We found that the synthetic contact matrices show qualitative similarities to the contact patterns in the empirically-constructed contact matrices. Models parameterised with the empirical and synthetic matrices generated similar findings with few differences observed in age groups where the empirical matrices have missing or aggregated age groups. This finding means that synthetic contact matrices may be used in modelling outbreaks in settings for which empirical studies have yet to be conducted.

Author(s):  
Kiesha Prem ◽  
Kevin van Zandvoort ◽  
Petra Klepac ◽  
Rosalind M Eggo ◽  
Nicholas G Davies ◽  
...  

Mathematical models have played a key role in understanding the spread of directly-transmissible infectious diseases such as Coronavirus Disease 2019 (COVID-19), as well as the effectiveness of public health responses. As the risk of contracting directly-transmitted infections depends on who interacts with whom, mathematical models often use contact matrices to characterise the spread of infectious pathogens. These contact matrices are usually generated from diary-based contact surveys. However, the majority of places in the world do not have representative empirical contact studies, so synthetic contact matrices have been constructed using more widely available setting-specific survey data on household, school, classroom, and workplace composition combined with empirical data on contact patterns in Europe. In 2017, the largest set of synthetic contact matrices to date were published for 152 geographical locations. In this study, we update these matrices with the most recent data and extend our analysis to 177 geographical locations. Due to the observed geographic differences within countries, we also quantify contact patterns in rural and urban settings where data is available. Further, we compare both the 2017 and 2020 synthetic matrices to out-of-sample empirically-constructed contact matrices, and explore the effects of using both the empirical and synthetic contact matrices when modelling physical distancing interventions for the COVID-19 pandemic. We found that the synthetic contact matrices reproduce the main traits of the contact patterns in the empirically-constructed contact matrices. Models parameterised with the empirical and synthetic matrices generated similar findings with few differences observed in age groups where the empirical matrices have missing or aggregated age groups. This finding means that synthetic contact matrices may be used in modelling outbreaks in settings for which empirical studies have yet to be conducted.


Author(s):  
Debi A. LaPlante ◽  
Heather M. Gray ◽  
Pat M. Williams ◽  
Sarah E. Nelson

Abstract. Aims: To discuss and review the latest research related to gambling expansion. Method: We completed a literature review and empirical comparison of peer reviewed findings related to gambling expansion and subsequent gambling-related changes among the population. Results: Although gambling expansion is associated with changes in gambling and gambling-related problems, empirical studies suggest that these effects are mixed and the available literature is limited. For example, the peer review literature suggests that most post-expansion gambling outcomes (i. e., 22 of 34 possible expansion outcomes; 64.7 %) indicate no observable change or a decrease in gambling outcomes, and a minority (i. e., 12 of 34 possible expansion outcomes; 35.3 %) indicate an increase in gambling outcomes. Conclusions: Empirical data related to gambling expansion suggests that its effects are more complex than frequently considered; however, evidence-based intervention might help prepare jurisdictions to deal with potential consequences. Jurisdictions can develop and evaluate responsible gambling programs to try to mitigate the impacts of expanded gambling.


Stanovnistvo ◽  
1999 ◽  
Vol 37 (1-4) ◽  
pp. 73-92
Author(s):  
Jelena Antonovic

Mass migration to urban areas constitutes the basic direct factor of the decline in rural population of Yugoslavia in the second half of the 20th century. Due to the characteristic migration patterns by age and sex, they have had a substantial impact on the change in age structure of rural population towards rapid demographic ageing. By inducing decline in fertility and an increase in mortality, the newly formed age structure is increasingly becoming one of the basic factors to further decline in population, or even the major factor to rural depopulation in the majority of regions. The paper analyzes changes in age structure of rural population in the FR of Yugoslavia and across its republics and provinces during the period from 1961 to 1991. The conditions prevailing during the last census (1991) are particularly highlighted. The author points to distinct differences in ageing of urban versus rural populations, and considerable regional differences at the achieved level of demographic age. Based on the main demographic age indicators (the share of five-year and larger age groups, average age, ageing index and movement in major age-specific contingents), the author concludes that the process of population ageing had taken place in both rural and urban populations, but was more intensive in villages (higher share of the aged, higher index of ageing and higher average age) during the period under review. The author points to distinct ageing of rural population in all republics and provinces. It was most prominent in central Serbia and Vojvodina, while being quite slow in Kosovo and Metohia and recorded mainly in between the last two censuses (1981-1991). Likewise, Kosovo and Metohia constitute the only major region of Yugoslavia in which rural population in 1991 is still demographically younger than the population in urban settlements. Rural versus urban population ageing was much more intensive in other major regions of the country, both from the base and from the apex of the age pyramid. In view of the minimal differences in fertility and mortality levels by type of settlement (particularly in central Serbia and Vojvodina), the author argues that the inherited age structure constitutes the main cause of rapid acceleration in rural population ageing in low fertility regions.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Cheryl Johnson ◽  
Moses Kumwenda ◽  
Jamilah Meghji ◽  
Augustine T. Choko ◽  
Mackwellings Phiri ◽  
...  

Abstract Background Despite the aging HIV epidemic, increasing age can be associated with hesitancy to test. Addressing this gap is a critical policy concern and highlights the urgent need to identify the underlying factors, to improve knowledge of HIV-related risks as well as uptake of HIV testing and prevention services, in midlife-older adults. Methods We conducted five focus group discussions and 12 in-depth interviews between April 2013 and November 2016 among rural and urban Malawian midlife-older (≥30 years) men and women. Using a life-course theoretical framework we explored how age is enacted socially and its implications on HIV testing and sexual risk behaviours. We also explore the potential for HIV self-testing (HIVST) to be part of a broader strategy for engaging midlife-older adults in HIV testing, prevention and care. Thematic analysis was used to identify recurrent themes and variations. Results Midlife-older adults (30–74 years of age) associated their age with respectability and identified HIV as “a disease of youth” that would not affect them, with age protecting them against infidelity and sexual risk-taking. HIV testing was felt to be stigmatizing, challenging age norms, threatening social status, and implying “lack of wisdom”. These norms drove self-testing preferences at home or other locations deemed age and gender appropriate. Awareness of the potential for long-standing undiagnosed HIV to be carried forward from past relationships was minimal, as was understanding of treatment-as-prevention. These norms led to HIV testing being perceived as a threat to status by older adults, contributing to low levels of recent HIV testing compared to younger adults. Conclusions Characteristics associated with age-gender norms and social position encourage self-testing but drive poor HIV-risk perception and unacceptability of conventional HIV testing in midlife-older adults. There is an urgent need to provide targeted messages and services more appropriate to midlife-older adults in sub-Saharan Africa. HIVST which has often been highlighted as a tool for reaching young people, may be a valuable tool for engaging midlife-older age groups who may not otherwise test.


Children ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 59
Author(s):  
Andrew Kampfschulte ◽  
Matthew Oram ◽  
Alejandra M. Escobar Vasco ◽  
Brittany Essenmacher ◽  
Amy Herbig ◽  
...  

Suicide frequency has tripled for some pediatric age groups over the last decade, of which, serious attempts result in pediatric intensive care unit (PICU) admissions. We paired clinical, aggregate geospatial, and temporal demographics to understand local community variables to determine if epidemiological patterns emerge that associate with risk for PICU admission. Data were extracted at an urban, high-volume, quaternary care facility from January 2011 to December 2017 via ICD 10 codes associated with suicide. Clinical, socioeconomic, geographical, and temporal variables were reviewed. In total, 1036 patients over the age of 9 were included, of which n = 161 were PICU admissions. Females represented higher proportions of all suicide-related hospital admissions (67.9%). Looking at race/ethnicity, PICU admissions were largely Caucasian (83.2%); Blacks and Hispanics had lower odds of PICU admissions (OR: 0.49; 0.17, respectively). PICU-admitted patients were older (16.0 vs. 15.5; p = 0.0001), with lower basal metabolic index (23.0 vs. 22.0; p = 0.0013), and presented in summer months (OR: 1.51, p = 0.044). Time-series decomposition showed seasonal peaks in June and August. Local regions outside the city limits identified higher numbers of PICU admissions. PICUs serve discrete geographical regions and are a source of information, when paired with clinical geospatial/seasonal analyses, highlighting clinical and societal risk factors associated with PICU admissions.


2021 ◽  
Vol 13 (13) ◽  
pp. 7313
Author(s):  
Mawuna Donald Houessou ◽  
Annemijn Cassee ◽  
Ben G. J. S. Sonneveld

A Rapid Food Security Appraisal among 240 rural and urban dwellers in southern Benin was conducted, using univariate and bivariate analyses, to evaluate the effects of the imposed COVID-19 ‘cordon sanitaire’ on food consumption patterns. As this is one of the first empirical studies on the COVID-19 food security nexus, we found that the raging pandemic has affected the food security pillars (availability, accessibility, utilization, and stability) in both rural and urban areas, within and outside the cordon sanitaire. The steepest decline was observed among respondents who live inside the cordon sanitaire, where rural producers and urban inhabitants without access to allotment gardens were hit hard. Increased food prices, disruptions in food logistics, and inability to work due to movement restrictions were most frequently indicated as reasons for the decline. Access to allotment gardens effectively supported households in mitigating the effects of the COVID-19 pandemic on the food crisis.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jackie Kleynhans ◽  
Stefano Tempia ◽  
Meredith L. McMorrow ◽  
Anne von Gottberg ◽  
Neil A. Martinson ◽  
...  

Abstract Background Describing contact patterns is crucial to understanding infectious disease transmission dynamics and guiding targeted transmission mitigation interventions. Data on contact patterns in Africa, especially South Africa, are limited. We measured and compared contact patterns in a rural and urban community, South Africa. We assessed participant and contact characteristics associated with differences in contact rates. Methods We conducted a cross-sectional study nested in a prospective household cohort study. We interviewed participants to collect information on persons in contact with for one day. We described self-reported contact rates as median number people contacted per day, assessed differences in contact rates based on participant characteristics using quantile regression, and used a Poisson model to assess differences in contact rates based on contact characteristics within age groups. We also calculated cumulative person hours in contact within age groups at different locations. Results We conducted 535 interviews (269 rural, 266 urban), with 17,252 contacts reported. The overall contact rate was 14 (interquartile range (IQR) 9–33) contacts per day. Those ≤18 years had higher contact rates at the rural site (coefficient 17, 95% confidence interval (95%CI) 10–23) compared to the urban site, for those aged 14–18 years (13, 95%CI 3–23) compared to < 7 years. No differences were observed for adults. There was a strong age-based mixing, with age groups interacting more with similar age groups, but also interaction of participants of all ages with adults. Children aged 14–18 years had the highest cumulative person hours in contact (116.3 rural and 76.4 urban). Conclusions Age played an important role in the number and duration of contact events, with children at the rural site having almost double the contact rate compared to the urban site. These contact rates can be utilized in mathematical models to assess transmission dynamics of infectious diseases in similar communities.


1994 ◽  
Vol 1 (4) ◽  
pp. 229-234 ◽  
Author(s):  
A Senthilselvan

OBJECTIVE: To examine the trends in hospitalization rates for atsthma in Saskatchewan from 1970 to 1989 and to investigate the differences in asthma hospitalization rates between rural and urban dwellers.DESIGN: Asthma hospitalization rates were calculated for the age groups O to 4, 5 to 9. 10 to 14, 15 to 24. 25 to 34. 35 to 49 and 50 to 64 years for the period between 1970 and 1989. Only the first admission in each year for each person was included in the analysis. As the classification of asthma changed in 1978. trends in asthma hospitalization rates were investigated separately for the periods 1970 to 1978 and 1979 to 1989. respectively. Rate ratios were obtained for male/female and rural/urban comparisons by fitting Poisson regression models.SETTING: The hospitalization data for respiratory diseases for the province of Saskatchewan were examined by age group, sex and place or residence.RESULT: No significant increases were observed in asthma hospitalization rates lrorn 1970 to 1978. In the period 1979 to 1989. asthma hospitalization rates increased significantly among children under four years from 4.31/1000 in 1979 to 7.04/1000 in 1989. Among children under 14 years. asthma hospitalization rates were greater in boys than in girls . The converse was true for adults aged 15 and above, with women having a higher hospitalization rate for asthma than men . In adults aged 35 and above. rural dwellers had higher hospitalization rates for asthma than urban dwellers throughout the study period. In other age groups, although rural dwellers had higher asthma hospitalization rates than did urban dwellers during 1970 to 1984. the differences disappered duri ng 1985 to 1989.CONCLUSION: Further studies are required to find reasons for the increase in asthma hospitalizations among young children under four years old and for the differences between rural and urban dwellers in the age group 35 years and above.


2017 ◽  
Vol 6 (5) ◽  
pp. 167-177
Author(s):  
Vipin Panwar ◽  
Ashok Aggarwal ◽  
Surinder Paul ◽  
Jitender Kumar ◽  
M. S. Saharan

Fusarium head blight (FHB) or head Scab is a very devastating fungal disease of wheat. Epidemics results with severe yield losses and overall seed quality reduction due to mycotoxins contaminated grains. Several species of Fusarium are found associated with the disease. But, incidence and severity of FHB and the composition of Fusarium species involved are reported to vary among geographical regions and years due to variations in climatic condi-tions and cropping practices. Climatic conditions, and even local variations in weather, can limit the range of species observed even if several are present, and influence their relative frequency of recovery. Our present study gives an idea about the distribution dynamics of FHB causing Fusarium spp. at three different locations in India. Most of the species can be found in much of geographical area affected but individual species dominate a specific re-gion. Analysis of the results of present study indicated that three Fusarium spp. i.e. F. graminearum, F. pallidoroseum and F. oxysporum were found as-sociated with FHB but F. graminearum was the dominant in all the location surveyed. Other two species are also associated with the disease but fre-quency was low. As these geographical locations represent different climatic conditions, the high relative distribution frequency of F. graminearum indi-cates its better adaptability to variable environmental conditions. Under-standing the pathogen distribution dynamics may also provide insights into the epidemiology and evolutionary potential of Fusarium spp. and could lead to improved management strategies under present climate change scenario.


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