Modeling and Analysis of the Spread of Carrier Dependent Infectious Diseases with Environmental Effects

2003 ◽  
Vol 11 (03) ◽  
pp. 325-335 ◽  
Author(s):  
Shikha Singh ◽  
Peeyush Chandra ◽  
J. B. Shukla
Keyword(s):  
Population Density ◽  
Infectious Diseases ◽  
Logistic Model ◽  
Human Population ◽  
Population Increase ◽  
Related Factors ◽  
Modeling And Analysis ◽  
Modeling Process ◽  
Per Capita ◽  
Carrier Population

In this paper, SIS and SIRS models for carrier dependent infectious diseases with immigration are proposed and analyzed by considering effects of environmental and human population related factors which are conducive to the growth of carrier population. In the modeling process, the density of carrier population is governed by a general logistic model. Further, it is assumed that the growth rate per capita and the modified carrying capacity of carrier population increase as the human population density increases. In each case, it is shown that the spread of an infectious disease increases as the carrier population density increases and the disease becomes more endemic due to immigration.

MATHEMATICAL MODELING AND ANALYSIS OF THE SPREAD OF CARRIER DEPENDENT INFECTIOUS DISEASES: EFFECTS OF CUMULATIVE DENSITY OF ENVIRONMENTAL FACTORS

2009 ◽  
Vol 02 (02) ◽  
pp. 213-228 ◽  
Author(s):  
SHIKHA SINGH ◽  
J. B. SHUKLA ◽  
PEEYUSH CHANDRA
Keyword(s):  
Environmental Factors ◽  
Infectious Diseases ◽  
Logistic Model ◽  
Cumulative Effect ◽  
Population Increase ◽  
Growth Equation ◽  
Nonlinear Mathematical Model ◽  
Modeling And Analysis ◽  
Dependent Growth ◽  
Carrier Population

In this paper, a nonlinear mathematical model with immigration for carrier dependent infectious diseases is proposed and analyzed by considering explicitly the cumulative effect of environmental factors, which are conducive to the growth of carrier population. It is assumed that the density of carrier population is governed by a general logistic model. It is assumed further that the growth rate per capita and the modified carrying capacity of carrier population increase as the cumulative density of environmental factors, governed by population density dependent growth equation, increases. It is shown that as the parameters governing environmental factors increase, the number of infectives in the population increases. It is also found that due to immigration, the disease becomes more endemic.

scholarly journals The effect of population density upon rate of reproduction with special reference to insects

1932 ◽  
Vol 111 (773) ◽  
pp. 437-454 ◽  
Keyword(s):  
Population Density ◽  
Death Rate ◽  
Human Population ◽  
Previous Investigation ◽  
Reproductive Rate ◽  
Small Cell ◽  
Harvard University ◽  
Population Increase ◽  
Modern Biology ◽  
The Individual

As the result of a previous investigation, involving the analysis of environmental factors controlling population increase in nature, it became apparent to the writer that population density constituted an environmental factor which had been comparatively neglected, doubtless on account of its obscurity, but whose effects were nevertheless of greater significance than generally realised. It seemed desirable, therefore, that this relatively obscure phenomenon should be investigated, and the writer commenced work at the Laboratory of General Physiology, Harvard University, U. S. A. It has long been known that crowding of animals produces definite and peculiar effects on the various vital processes, and even the morphology of the individual. For instance, as far back as 1854, Hogg produced evidence to show that a snail kept in a small cell would only grow to such a size as would enable it to move about freely. Later, Semper (1874) came to the conclusion that there was a relationship between volume and the ultimate size of the individual. As regards the effect of crowding upon reproductive rate the first observation appears to have been made by Balbiani (1860), who reported that Paramecium must be placed in not less than 2-3 c. c. of medium to bring about maximum productivity. Again, Farr (1843) showed that there existed a definite relationship between the density of the human population and the death-rate, and anticipated the trend of modern biology to the extent of elaborating a mathematical formula which conformed to his findings.

scholarly journals ESBL/AmpC-Producing Escherichia coli in Wild Boar: Epidemiology and Risk Factors

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1855
Author(s):  
Nicoletta Formenti ◽  
Stefania Calò ◽  
Giovanni Parisio ◽  
Flavia Guarneri ◽  
Laura Birbes ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Population Density ◽  
Wild Boar ◽  
Human Population ◽  
Linear Models ◽  
Environmental Indicators ◽  
Related Factors ◽  
Human Population Density ◽  
E Coli ◽  
Human Interface

The complex health problem of antimicrobial resistance (AMR) involves many host species, numerous bacteria and several routes of transmission. Extended-spectrum β-lactamase and AmpC (ESBL/AmpC)-producing Escherichia coli are among the most important strains. Moreover, wildlife hosts are of interest as they are likely antibiotics free and are assumed as environmental indicators of AMR contamination. Particularly, wild boar (Sus scrofa) deserves attention because of its increased population densities, with consequent health risks at the wildlife–domestic–human interface, and the limited data available on AMR. Here, 1504 wild boar fecal samples were microbiologically and molecularly analyzed to investigate ESBL/AmpC-producing E. coli and, through generalized linear models, the effects of host-related factors and of human population density on their spread. A prevalence of 15.96% of ESBL/AmpC-producing E. coli, supported by blaCTX-M (12.3%), blaTEM (6.98%), blaCMY (0.86%) and blaSHV (0.47%) gene detection, emerged. Young animals were more colonized by ESBL/AmpC strains than older subjects, as observed in domestic animals. Increased human population density leads to increased blaTEM prevalence in wild boar, suggesting that spatial overlap may favor this transmission. Our results show a high level of AMR contamination in the study area that should be further investigated. However, a role of wild boar as a maintenance host of AMR strains emerged.

scholarly journals Analysis of a Vaccination Model for Carrier Dependent Infectious Diseases with Environmental Effects

2008 ◽  
Vol 13 (3) ◽  
pp. 331-350 ◽  
Author(s):  
Ram Naresh ◽  
Surabhi Pandey ◽  
A. K. Misra
Keyword(s):  
Infectious Diseases ◽  
Logistic Model ◽  
Reproduction Number ◽  
Size Structure ◽  
Backward Bifurcation ◽  
Threshold Condition ◽  
Nonlinear Mathematical Model ◽  
Variable Size ◽  
Carrier Population

We have proposed and analyzed a nonlinear mathematical model for the spread of carrier dependent infectious diseases in a population with variable size structure including the role of vaccination. It is assumed that the susceptibles become infected by direct contact with infectives and/or by the carrier population present in the environment. The density of carrier population is assumed to be governed by a generalized logistic model and is dependent on environmental and human factors which are conducive to the growth of carrier population. The model is analyzed using stability theory of differential equations and numerical simulation. We have found a threshold condition, in terms of vaccine induced reproduction number R(φ) which is, if less than one, the disease dies out in the absence of carriers provided the vaccine efficacy is high enough, and otherwise the infection is maintained in the population. The model also exhibits backward bifurcation at R(φ) = 1. It is also shown that the spread of an infectious disease increases as the carrier population density increases. In addition, the constant immigration of susceptibles makes the disease more endemic.

MODELING THE CUMULATIVE EFFECT OF ECOLOGICAL FACTORS IN THE HABITAT ON THE SPREAD OF TUBERCULOSIS

2009 ◽  
Vol 02 (03) ◽  
pp. 339-355 ◽  
Author(s):  
RAM NARESH ◽  
SURABHI PANDEY ◽  
J. B. SHUKLA
Keyword(s):  
Population Density ◽  
Logistic Model ◽  
Human Population ◽  
Numerical Study ◽  
Ecological Factors ◽  
Cumulative Effect ◽  
Density Dependent ◽  
Analytical Results

In this paper, the cumulative effect of ecological factors in the habitat on the spread of tuberculosis (TB) in human population is modeled and analyzed. The total human population is divided into two classes, susceptibles and infectives. It is assumed that TB is not only spread by direct contacts with infectives in the population but also indirectly by bacteria which are emitted by infectives in the habitat. It is assumed further that bacteria survive due to conducive ecological factors such as flower pots, plants, grasses, human clothes, etc. in the habitat. The cumulative density of ecological factors in the habitat is assumed to be governed by a population density dependent logistic model. The analysis of the model shows that as parameters governing the conducive ecological factors in the habitat increase, the spread of TB increases. The same result is also found with the increase in the parameter governing the survival and accumulation of bacteria in the habitat. It is further found that due to immigration of the population TB becomes more endemic. A numerical study of the model is also carried out to support the analytical results.

Haemophilia Registry of the Medical Committee of the Swiss Haemophilia Society

2009 ◽  
Vol 29 (S 01) ◽  
pp. S16-S18 ◽  
Author(s):  
B. Brand ◽  
N. von der Weid
Keyword(s):  
Quality Control ◽  
Infectious Diseases ◽  
Mutation Analysis ◽  
Clinical Data ◽  
Age Groups ◽  
Treatment Modalities ◽  
Global Survey ◽  
On Demand ◽  
Per Capita ◽  
Severity Of The Disease

SummaryThe Swiss Haemophilia Registry of the Medical Committee of the Swiss Haemophilia Society was established in 2000. Primarily it bears epidemiological and basic clinical data (incidence, type and severity of the disease, age groups, centres, mortality). Two thirds of the questions of the WFH Global Survey can be answered, especially those concerning use of concentrates (global, per capita) and treatment modalities (on-demand versus prophylactic regimens). Moreover, the registry is an important tool for quality control of the haemophilia treatment centres.There are no informations about infectious diseases like hepatitis or HIV, due to non-anonymisation of the data. We plan to incorporate the results of the mutation analysis in the future.

Impact of Environmental Degradation on Human Health

2016 ◽  
Vol 3 (1) ◽  
pp. 1 ◽  
Author(s):  
_______ Archana ◽  
Charu Datta ◽  
Pratibha Tiwari
Keyword(s):  
Environmental Degradation ◽  
Human Population ◽  
Environmental Problems ◽  
Population Increase ◽  
Human Beings ◽  
The People ◽  
Wide Range ◽  
Different Types ◽  
Economic Institute ◽  
Day By Day

Degradation of environment is one of the most serious challenges before the mankind in today’s world. Mankind has been facing a wide range of problem arising out of the degradation of environment. Not only the areas under human inhabitation, but the areas of the planet without human population have also been suffering from these problems. As the population increase day by day, the amenities are not improved simultaneously. With the advancement of science and technologies the needs of human beings has been changing rapidly. As a result different types of environmental problems have been rising. Environmental degradation is a wide- reaching problem and it is likely to influence the health of human population is great. It may be defined the deterioration of the environment through depletion of resources such as air, water, and soil. The destruction of ecosystem and extinction of wildlife. Environmental degradation has occurred due to the recent activities in the field of socio-economic, institute and technology. Poverty still remains a problem as the root of several environmental problems to create awareness among the people about the ill effect of environmental pollution. In the whole research it is clear that all factors of environmental degradation may be reduced through- Framing the new laws on environmental degradation, Environment friend policy, Controlling all the ways and means of noise, air, soil and water pollution, Through growing more and more trees and by adapting the proper sanitation policy.  

scholarly journals Toward a Dualistic Growth? Population Increase and Land-Use Change in Rome, Italy

Land ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 749
Author(s):  
Leonardo Bianchini ◽  
Gianluca Egidi ◽  
Ahmed Alhuseen ◽  
Adele Sateriano ◽  
Sirio Cividino ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Population Growth ◽  
Mediterranean Basin ◽  
Urban Expansion ◽  
Arable Land ◽  
Central Italy ◽  
Agricultural Landscapes ◽  
Population Increase ◽  
Per Capita

The spatial mismatch between population growth and settlement expansion is at the base of current models of urban growth. Empirical evidence is increasingly required to inform planning measures promoting urban containment in the context of a stable (or declining) population. In these regards, per-capita indicators of land-use change can be adopted with the aim at evaluating long-term sustainability of urbanization processes. The present study assesses spatial variations in per-capita indicators of land-use change in Rome, Central Italy, at five years (1949, 1974, 1999, 2008, and 2016) with the final objective of quantifying the mismatch between urban expansion and population growth. Originally specialized in agricultural productions, Rome’s metropolitan area is a paradigmatic example of dispersed urban expansion in the Mediterranean basin. By considering multiple land-use dynamics, per-capita indicators of landscape change delineated three distinctive waves of growth corresponding with urbanization, suburbanization, and a more mixed stage with counter-urbanization and re-urbanization impulses. By reflecting different socioeconomic contexts on a local scale, urban fabric and forests were identified as the ‘winner’ classes, expanding homogeneously over time at the expense of cropland. Agricultural landscapes experienced a more heterogeneous trend with arable land and pastures declining systematically and more fragmented land classes (e.g., vineyards and olive groves) displaying stable (or slightly increasing) trends. The continuous reduction of per-capita surface area of cropland that’s supports a reduced production base, which is now insufficient to satisfy the rising demand for fresh food at the metropolitan scale, indicates the unsustainability of the current development in Rome and more generally in the whole Mediterranean basin, a region specialized traditionally in (proximity) agricultural productions.

scholarly journals COVID-19 Mortality Rate and Its Incidence in Latin America: Dependence on Demographic and Economic Variables

2021 ◽  
Vol 18 (13) ◽  
pp. 6900
Author(s):  
Javier Cifuentes-Faura
Keyword(s):  
Latin America ◽  
Mortality Rate ◽  
Population Density ◽  
Life Expectancy ◽  
Latin American ◽  
Positive Influence ◽  
Death Rates ◽  
Per Capita ◽  
Latin American Countries ◽  
Quality Infrastructure

The pandemic caused by COVID-19 has left millions infected and dead around the world, with Latin America being one of the most affected areas. In this work, we have sought to determine, by means of a multiple regression analysis and a study of correlations, the influence of population density, life expectancy, and proportion of the population in vulnerable employment, together with GDP per capita, on the mortality rate due to COVID-19 in Latin American countries. The results indicated that countries with higher population density had lower numbers of deaths. Population in vulnerable employment and GDP showed a positive influence, while life expectancy did not appear to significantly affect the number of COVID-19 deaths. In addition, the influence of these variables on the number of confirmed cases of COVID-19 was analyzed. It can be concluded that the lack of resources can be a major burden for the vulnerable population in combating COVID-19 and that population density can ensure better designed institutions and quality infrastructure to achieve social distancing and, together with effective measures, lower death rates.

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