scholarly journals Incorporating household structure and demography into models of endemic disease

2019 ◽  
Vol 16 (157) ◽  
pp. 20190317 ◽  
Author(s):  
Joe Hilton ◽  
Matt J. Keeling

The spread of infectious diseases is intimately linked with the strength and type of contact between individuals. Multiple observational and modelling studies have highlighted the importance of two forms of social mixing: age structure, where the likelihood of interaction between two individuals is determined by their ages; and household structure, which recognizes the much stronger contacts and hence transmission potential within the family setting. Age structure has been ubiquitous in predictive models of both endemic and epidemic infections, in part due to the ease of assessing someone’s age. By contrast, although household structure is potentially the dominant heterogeneity, it has received less attention, in part due to an absence of the necessary methodology. Here, we develop the modelling framework necessary to predict the behaviour of endemic infections (which necessitates capturing demographic processes) in populations that possess both household and age structure. We compare two childhood infections, with measles-like and mumps-like parameters, and two populations with UK-like and Kenya-like characteristics, which allows us to disentangle the impact of epidemiology and demography. For this high-dimensional model, we predict complex nonlinear dynamics, where the dynamics of within-household outbreaks are tempered by historical waves of infection and the immunity of older individuals.

Author(s):  
Svitlana Vesperis ◽  
Hanna Samus ◽  
Olha Scherbina

The article analyzes the impact of demographic processes on the economic security of Sumy region. The main characteristics of economic security of the region are highlighted. It is noted that the population of the country is a kind of foundation through which all types of national security, including economic, have their practical application. The following demographic characteristics of the population are analyzed, such as birth rate, death rate, sex and age structure, quantity, migration, which determine the available labor potential of the region and significantly affect the formation of economic security in the region. The negative tendency of reduction of the available population of the region is established. The sex composition of the population is insignificantly, but women predominate. The natural increase in the population of the region is a negative indicator, which indicates a decrease in the population of the region. Negative dynamics is characteristic of the marriage rate. Divorce is growing in the region. All this indicates the decline of the institution of the family, which in turn will affect the birth rate. With regard to migration growth (reduction) in general, it should be noted that this indicator is also negative, so the number of arrivals is less than the number of departures. But the exception is interstate migration, which is characterized by positive dynamics for the region. The region is dominated by the working age population, which is positive for economic security. At the same time, the share of people of retirement age is greater than children. In order to solve demographic problems and improve the economic security of the region, measures should be implemented at the regional level (except national ones) to increase the birth rate, support the development of medical institutions to reduce mortality, which will increase natural population growth. Considerable attention should be paid to the development of the production sphere and the sphere of services in order to reduce migration flows from the region and provide available labor resources with jobs, taking into account the gender and age structure. It is necessary to improve the socio-economic living conditions of the population, which will stimulate the migration flow of the population. These events will contribute to the stable and gradual development of the demographic component of economic security of Sumy region.


2020 ◽  
Author(s):  
Emma L Davis ◽  
T Déirdre Hollingsworth ◽  
Matt J Keeling

Abstract Background: Vector control is a vital tool utilised by malaria control and elimination programmes worldwide, and as such it is important that we can accurately quantify the expected public health impact of a range of vector control methods. There are very few previous models that consider vector control induced changes in the age-structure of the vector population and the resulting impact this will have on transmission.Methods: The steady-state solution of a novel age-structured deterministic compartmental model describing the mosquito gonotrophic cycle is analytically derived, with the age of each mosquito measured in the number of gonotrophic cycles (or successful blood meals) completed. From this model we derive analytical expressions for key transmission measures, such as the effective reproductive ratio under control, Rc, and investigate the impact of commonly used vector control methods on the age-structure of the vector population.Results: We derive and analyse a novel model with an explicit solution that can be used to directly quantify key transmission statistics and investigate the age-structured impact of vector control. Application of this model confirms current knowledge that adult-acting interventions, such as IRS or LLINs, are highly effective at reducing transmission, particularly in comparison to larvicide usage at the same coverage. We also find that scaling up coverage results in a wider gap in transmission reduction between adult-active and larval-based interventions. For LLINs and IRS the effective reproductive ratio under control, Rc, decreases exponentially with coverage, whereas for larvicides the relationship is linear. We also find that mid-ranges of LLIN coverage see the largest effect of reduced net integrity on transmission.Conclusions: Well-maintained, adult-acting vector control measures are substantially more effective than larval-based action at reducing the transmission potential of the mosquito population, particularly at medium to high coverage levels.


Author(s):  
Paride O. Lolika ◽  
Mohamed Y. A. Bakhet ◽  
Ben Saliba Lagure

Bovine tuberculosis and bovine brucellosis continue to cause serious economic and public health burden in low-income countries, especially in many regions of sub-Saharan Africa where the diseases are co-endemic. The economic burden of the two infections in low-income countries trigger important questions about the optimal intervention strategies in co-endemic regions. Hence, the need for comprehensive modelling studies to address such questions is therefore essential, yet only a limited of such studies exist to date despite the power of models to predict the future and, most importantly, to quantify the uncertainty in these predictions. Here, we develop a brucellosistuberculosis co-infection modelling framework that incorporates all relevant biological factors and culling of infectious animals-as the sole intervention strategy. We performed an optimal control study to assess the impact of culling infectious animals on controlling the prevalence of the two infections. Two objective functions have been considered, a linear and a quadratic. Existence and the characterization of the optimal control has been determined. Numerical results are carried out to illustrate the main findings. Our findings highlight the importance of optimal culling on controlling the spread of two infections.


Author(s):  
Maria Chiara Fastame ◽  
Ilaria Mulas ◽  
Valeria Putzu ◽  
Gesuina Asoni ◽  
Daniela Viale ◽  
...  

AbstractThe effect of the COVID-19 on the physical and mental health of Italian older individuals displaying signs of cognitive deterioration has not been deeply investigated. This longitudinal study examined the impact of COVID-19 lockdown measures on the psychological well-being and motor efficiency of a sample of Italian community-dwellers with and without cognitive decline. Forty-seven participants underwent instrumental gait analysis performed in ecological setting using wearable sensors, and completed a battery of tasks assessing cognitive functioning and psychological well-being, before and after the full lockdown due to the COVID-19 spreading. A series of Multivariate Analyses of Variance (MANOVAs) documented that the superior gait performance of the cognitively healthy participants exhibited before the COVID-19 spread, vanished when they were tested at the end of the lockdown period. Moreover, before the outbreak of the COVID-19, cognitively healthy participants and those with signs of cognitive decline reported similar levels of psychological well-being, whereas, after the lockdown, the former group reported better coping, emotional competencies, and general well-being than the participants displaying signs of cognitive decline. In conclusion, the full COVID-19 outbreak had a significant impact on the mental and motor functioning of older individuals with and without signs of cognitive deterioration living in Italy.


2021 ◽  
Vol 13 (13) ◽  
pp. 7386
Author(s):  
Thomas Schaubroeck ◽  
Simon Schaubroeck ◽  
Reinout Heijungs ◽  
Alessandra Zamagni ◽  
Miguel Brandão ◽  
...  

To assess the potential environmental impact of human/industrial systems, life cycle assessment (LCA) is a very common method. There are two prominent types of LCA, namely attributional (ALCA) and consequential (CLCA). A lot of literature covers these approaches, but a general consensus on what they represent and an overview of all their differences seems lacking, nor has every prominent feature been fully explored. The two main objectives of this article are: (1) to argue for and select definitions for each concept and (2) specify all conceptual characteristics (including translation into modelling restrictions), re-evaluating and going beyond findings in the state of the art. For the first objective, mainly because the validity of interpretation of a term is also a matter of consensus, we argue the selection of definitions present in the 2011 UNEP-SETAC report. ALCA attributes a share of the potential environmental impact of the world to a product life cycle, while CLCA assesses the environmental consequences of a decision (e.g., increase of product demand). Regarding the second objective, the product system in ALCA constitutes all processes that are linked by physical, energy flows or services. Because of the requirement of additivity for ALCA, a double-counting check needs to be executed, modelling is restricted (e.g., guaranteed through linearity) and partitioning of multifunctional processes is systematically needed (for evaluation per single product). The latter matters also hold in a similar manner for the impact assessment, which is commonly overlooked. CLCA, is completely consequential and there is no limitation regarding what a modelling framework should entail, with the coverage of co-products through substitution being just one approach and not the only one (e.g., additional consumption is possible). Both ALCA and CLCA can be considered over any time span (past, present & future) and either using a reference environment or different scenarios. Furthermore, both ALCA and CLCA could be specific for average or marginal (small) products or decisions, and further datasets. These findings also hold for life cycle sustainability assessment.


2009 ◽  
Vol 85 (3) ◽  
pp. 269-287 ◽  
Author(s):  
Werner Bönte ◽  
Oliver Falck ◽  
Stephan Heblich
Keyword(s):  

Author(s):  
Beschasnyi S.P. ◽  
Lysenko E.M. ◽  
Hasiuk O.M. ◽  
Erlish О.О.

Carbon monoxide is a toxic gas that is colourless, odourless, and has the potential to cause momentaryhypoxia by bonding with heme-inspired proteins. Because of these properties, it causes the highest number of toxications. Due to its properties, this gas causes damage to the nervous and cardiovascular system. The development of anoxia is associated with the impact on the system of oxidative phosphorylation in mitochondria and the development of oxidative stress in the body. The body produces a small amount of carbon monoxide as a result of erythrocyte breakdown. Picomolar concentrations of carbon monoxide even have anti-inflammatory, antiapoptotic,cytoprotective and antiproliferative properties. Kidney is one of the first organs,that responds to the occurrence of hypoxia, are responsible for the removal of products of metabolism and toxicants, including ethanol. For the study, the blood and urine samples were taken from patients with acute intoxication. The amount of methemoglobin in the blood was determined by spectrophotometric method. The concentration of ethanol in blood and urine was measured by gas-liquid chromatography method. The correlation analysis showed that carbon monoxide affects the rate of excretion of ethanol from the body. Among individuals under 40 years of age, there was a correlation between the level of carbon monoxide and the amount of ethanol in the blood. Among older adults this correlation was not established. A direct correlation with the level of this gas in the blood and the level of ethanol in the urine among people under 40 years of age was found. Among older individuals, the opposite was observed –a high level of methemoglobin was responsible for the decreased level of ethanol. There were no correlations between methemoglobin level and age. Comparison of the studied indices did not show any sexual differences in ethanol excretion, but there were age specific features: ethanol excretion under the influence of carbon monoxide among people under 40 years old was more accelerated.Key words:hypoxia, CO intoxication, blood, methemoglobin, kidneys. Монооксид карбону являє собою токсичний газ, який не має кольору,без запаху та здатен спричиняти миттєву гіпоксію шляхом зв’язування з гем-вмісними білками. Через такі властивості він спричиняє найбільшу кількість отруєнь. Цей газ,завдяки своїм властивостям,спричиняє ураження нервової та серцево-судинної системи. Розвиток аноксії пов’язаний із впливом на систему окисного фосфорилювання у мітохондріях та розвиткомоксидативного стресу. В організмі продукується невелика кількість ендогенного монооксиду карбону внаслідок розпаду еритроцитів. Пікомолярні концентрації монооксиду карбону навіть володіють протизапальними, антиапоптичними, цитопротекторними та антипроліферативними властивостями. Нирки є одним із перших органів, який реагує на розвитокгіпоксії, вони відповідають за видалення продуктів метаболізму й токсикантів, зокрема етанолу.Зміни у функціонуванні нирок відображаються на загальному стані організму.Для дослідження отримували зразки крові та сечі від осіб із гострою інтоксикацією. У крові спектрофотометричним методом визначали вміст метгемоглобіну, який утворювався внаслідок вдихання монооксиду карбону та відповідного потрапляння до кровоносної системи. Методом газово-рідинної хроматографії вимірювали концентрацію етанолу у крові та сечі. Розрахунок кореляційних зв’язків показав, що монооксид карбону впливає на швидкість екскреції етанолу. У осіб до 40 років спостерігалася кореляція між показником рівня метгемоглобінута вмістом етанолу у крові. У осіб старшого віку цього зв’язку не встановлено. Виявлено прямий зв’язок із рівнем цього газу у крові та рівнем етанолу в сечі у осіб до 40 років. У осіб старшого віку спостерігалася зворотня реакція–високий рівень метгемоглобінуобумовлював зниження рівня етанолу. Кореляційні зв’язки між вмістом метгемоглобіну та віком не було виявлено. Порівняння досліджуваних показників не виявило статевих відмінностей у екскреції етанолу, проте виявлено вікові особливості: екскреція етанолу в умовах впливу монооксиду карбону в осіб до 40 років була більш пришвидшена.Таким чином, можна стверджувати, що монооксид карбону обумовлює зміни у функціональній активності нирок.Ключові слова:гіпоксія, інтоксикація СО, кров, метгемоглобін, нирки.


2018 ◽  
Vol 9 ◽  
pp. 215145931878345 ◽  
Author(s):  
Carmen E. Quatman ◽  
Michael Mondor ◽  
Jodi Halweg ◽  
Julie A. Switzer

Objective: To determine whether fall calls, lift assists, and need for transport to the hospital over the past 10 years in one emergency medical services (EMS) system have altered coincident with demographic changes and to estimate health-care cost for lift assists. Methods: We conducted a retrospective chart review of EMS fall-related care. The HealthEMS database for a suburban community surveyed was queried from March 1, 2007, to March 1, 2017. Fall-related calls in patients 60 years or older were identified and determined to be either lift assists (calls that do not result in transport) or fall calls that resulted in transport to the hospital. Results: Of the 38 237 EMS care responses in patients 60 years or older, 11.5% were related to falls. Fall calls increased by 268% over the past 10 years ( P = .0006), yet the number of transports to the hospital significantly decreased over time ( P = .02). Lift assists increased significantly ( P = .0003), nearly doubling over the decade. At the same time, fall calls that did not result in transport to the hospital cost the community an estimated US$1.5 million over a 10-year period. Discussion: There has been a dramatic shift in fall-related calls to EMS in older individuals with more frequent calls for lesser acuity needs. Utilization of EMS for lift assists has substantial financial consequences and diverts care from calls that need immediate triage and transport to care. Conclusion: Future work to reduce the frequency and increase the impact of EMS lift assists could have a significant cost benefit and provide opportunity for enrollment in appropriate community services and fall prevention programs.


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