On the mathematical modelling and analysis of Listeriosis from contaminated food products

Listeriosis is a foodborne disease caused by a bacterium known as Listeria monocytogenes. Humans can be infected by consuming contaminated food products. A transmission can also occur through contact with infected animals or people, however to a less extent. In this paper, a mathematical model for Listeriosis dynamics was developed. The steady states and their stability of the model system were determined and analyzed. The result shows that the disease free equilibrium is asymptotically stable if the bacteria growth rate is less than its removal rate, and also the growth rate of food contamination is less than its removal rate. It was further observed that we can still have Listeriosis driven by the contaminated food products even if the Listeria bacteria population in the environment is very small. The results indicate that Listeriosis can be effectively controlled by removing contaminated food products, which was the policy adopted by the South African government during the recent Listeriosis outbreak.

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Modelling the potential role of media campaigns on the control of Listeriosis

Mathematical Biosciences and Engineering ◽

10.3934/mbe.2021375 ◽

2021 ◽

Vol 18 (6) ◽

pp. 7580-7601

Author(s):

C. W. Chukwu ◽

◽

F. Nyabadza ◽

Fatmawati ◽

◽

...

Keyword(s):

Removal Rate ◽

Bacterial Pathogen ◽

Food Contamination ◽

Food Products ◽

Model Parameters ◽

Media Campaigns ◽

Awareness Campaigns ◽

Contaminated Food ◽

The Impact

<abstract><p>Human Listeria infection is a food-borne disease caused by the consumption of contaminated food products by the bacterial pathogen, Listeria. In this paper, we propose a mathematical model to analyze the impact of media campaigns on the spread and control of Listeriosis. The model exhibited three equilibria namely; disease-free, Listeria-free and endemic equilibria. The food contamination threshold is determined and the local stability analyses of the model is discussed. Sensitivity analysis is done to determine the model parameters that most affect the severity of the disease. Numerical simulations were carried out to assess the role of media campaigns on the Listeriosis spread. The results show that; an increase in the intensity of the media awareness campaigns, the removal rate of contaminated food products, a decrease in the contact rate of Listeria by humans results in fewer humans getting infected, thus leading to the disease eradication. An increase in the depletion of media awareness campaigns results in more humans being infected with Listeriosis. These findings may significantly impact policy and decision-making in the control of Listeriosis disease.</p></abstract>

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Modeling the Potential Role of Media Campaigns on the Control of Listeriosis

10.1101/2020.12.22.20248698 ◽

2020 ◽

Author(s):

C.W. Chukwu ◽

F. Nyabadza

Keyword(s):

Bacterial Pathogen ◽

Food Contamination ◽

Food Products ◽

Model Parameters ◽

Asymptotically Stable ◽

Media Campaigns ◽

Awareness Campaigns ◽

The Impact ◽

Disease Free

AbstractThe human Listeriosis infection is a food-borne disease caused by the consumption of food products contaminated by the bacterial pathogen, Listeria. In this paper, we propose a mathematical model to analyse the impact of media awareness campaigns on the spread and control of Listeriosis. The model equilibria are determined and the model has three equilibria namely; the disease-free, the Listeria-free, and the endemic equilibria. The food contamination constant (ℛf) is determined and the stability analysis shows that the disease-free steady state is locally asymptotically stable if ℛf < 1, the Listeria-free and endemic steady states are locally asymptotically stable whenever ℛf > 1. Sensitivity analysis is done to determine the model parameters that most affect the severity of the disease. Numerical simulations are carried out to determine the role of media awareness campaigns on the spread of the Listeriosis. The results show that an increase in the intensity of the media awareness campaigns and removal of contaminated food products, a decrease in the contact rate, results in fewer humans getting infected leading to disease eradication, while an increase in the depletion of media awareness campaigns results in more humans been infected with Listeriosis. These findings may significantly impact policy and decision making in the control of Listeriosis disease.

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A Theoretical Model of Listeriosis Driven by Cross Contamination of Ready-to-Eat Food Products

International Journal of Mathematics and Mathematical Sciences ◽

10.1155/2020/9207403 ◽

2020 ◽

Vol 2020 ◽

pp. 1-14 ◽

Cited By ~ 1

Author(s):

C. W. Chukwu ◽

F. Nyabadza

Keyword(s):

Equilibrium Points ◽

Disease Outbreaks ◽

Latin Hypercube Sampling ◽

Food Products ◽

Processing Plant ◽

Cross Contamination ◽

Plant Environment ◽

Significant Public Health ◽

Contaminated Food ◽

Disease Free

Cross contamination that results in food-borne disease outbreaks remains a major problem in processed foods globally. In this paper, a mathematical model that takes into consideration cross contamination of Listeria monocytogenes from a food processing plant environment is formulated using a system of ordinary differential equations. The model has three equilibria: the disease-free equilibrium, Listeria-free equilibrium, and endemic equilibrium points. A contamination threshold ℛwf is determined. Analysis of the model shows that the disease-free equilibrium point is locally stable for ℛwf<1 while the Listeria-free and endemic equilibria are locally stable for ℛwf>1. The time-dependent sensitivity analysis is performed using Latin hypercube sampling to determine model input parameters that significantly affect the severity of the listeriosis. Numerical simulations are carried out, and the results are discussed. The results show that a reduction in the number of contaminated workers and removal of contaminated food products are essential in eliminating the disease in the human population and vice versa. The results have significant public health implications in the management and containment of any listeriosis disease outbreak.

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The Engagement of Beneficiaries in Farm Governance of Restituted Land through the Communal Property Association Model: The Ideal Versus the Reality of Beneficiary Farms in South Africa

Commonwealth Youth and Development ◽

10.25159/2663-6549/5968 ◽

2019 ◽

Vol 16 (2) ◽

Author(s):

Mokoko Piet Sebola ◽

Malemela Angelinah Mamabolo

Keyword(s):

South Africa ◽

South African ◽

Land Reform ◽

Farm Management ◽

The South ◽

African Government ◽

Communal Property ◽

Farm Ownership ◽

Land Restitution ◽

Communal Property Associations

The purpose of this article is to evaluate the engagement of farm beneficiaries in South Africa in the governance of restituted farms through communal property associations. The South African government has already spent millions of rands on land restitution to correct the imbalance of the past with regard to farm ownership by the African communities. Various methods of farm management to benefit the African society have been proposed, however, with little recorded success. This article argues that the South African post-apartheid government was so overwhelmed by political victory in 1994 that they introduced ambitious land reform policies that were based on ideal thinking rather than on a pragmatic approach to the South African situation. We used qualitative research methods to argue that the engagement of farm beneficiaries in farm management and governance through communal property associations is failing dismally. We conclude that a revisit of the communal property associations model is required in order to strengthen the position of beneficiaries and promote access to land by African communities for future benefit.

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Exploring the South African Government Communication on Land Expropriation without Compensation

Journal of Human Ecology ◽

10.31901/24566608.2020/72.1-3.3275 ◽

2020 ◽

Vol 72 (1-3) ◽

Author(s):

Lungisani Moyo

Keyword(s):

South Africa ◽

Food Security ◽

South African ◽

Small Scale ◽

South African Government ◽

Eastern Cape ◽

The South ◽

Land Expropriation ◽

African Government ◽

Government Communication

ABSTRACT This paper used qualitative methodology to explore the South African government communication and land expropriation without compensation and its effects on food security using Alice town located in the Eastern Cape Province South Africa as its case study. This was done to allow the participants to give their perceptions on the role of government communication on land expropriation without compensation and its effects on South African food security. In this paper, a total population of 30 comprising of 26 small scale farmers in rural Alice and 4 employees from the Department of Agriculture (Alice), Eastern Cape, South Africa were interviewed to get their perception and views on government communications and land expropriation without compensation and its effects on South African food security. The findings of this paper revealed that the agricultural sector plays a vital role in the South African economy hence there is a great need to speed up transformation in the sector.

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Fire on the Mountain: Reinvigorating Legislative Measures to Quench the Flame of Illicit Drug Use in South Africa

Asian Journal of Interdisciplinary Research ◽

10.34256/ajir2032 ◽

2020 ◽

Vol 3 (2) ◽

pp. 15-29

Author(s):

Sogo Angel Olofinbiyi ◽

Thembelihle Mtambo

Keyword(s):

South Africa ◽

Drug Use ◽

South African ◽

Illicit Drugs ◽

Illicit Drug ◽

Illicit Drug Use ◽

Critical Discussion ◽

African Government ◽

Clear Cut ◽

Legislative Measures

South African societies have been characterized by the prolific incidence of illicit drug use in recent times. The paper attempts to examine the legislations implemented on the use of illicit drugs in South Africa. The study adopts a review of the literature to identify and describe the most common illicit drugs used around South Africa communities, placing emphasis on the policies developed by the South African government in combating these situations. The research follows a critical discussion on the issues associated with drug use, its causes, as well as its effects on humans and the environment. The study recommends relevant initiatives to combat all intricacies associated with drug use within the country. This approach will be appropriate in facilitating a clear-cut understanding of the possible remedies to quench the burning flame of illicit drug use across a broad range of South African communities.

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Shear Loss Characteristics of an Aerobic Biofilm

Water Science & Technology ◽

10.2166/wst.1992.0439 ◽

1992 ◽

Vol 26 (3-4) ◽

pp. 595-600 ◽

Cited By ~ 10

Author(s):

S. M. Rao Bhamidimarri ◽

T. T. See

Keyword(s):

Growth Rate ◽

Shear Stress ◽

Film Thickness ◽

Removal Rate ◽

Surface Growth ◽

Phenol Removal ◽

Concentric Cylinder ◽

Substrate Utilisation ◽

Utilisation Rate ◽

Net Growth Rate

Growth and shear loss characteristics of phenol utilizing biofilm were studied in a concentric cylinder bioreactor. The net accumulation of the biofilm and the substrate utilisation were measured as a function of torque. Uniform biofilms were obtained up to a thickness of around 300 microns, beyond which the surface growth was non-uniform. The substrate utilisation rate, however, reached a constant value beyond film thickness of 50 to 100 microns depending on the operational torque. The maximum phenol removal rate was achieved at a shear stress of 3.5 Nm-2. The effect of shear stress on net growth rate was found to be described byand a zero net growth was obtained at a shear stress of 18.7 Nm-2.

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A Review of Medical Waste Management in South Africa

Open Environmental Sciences ◽

10.2174/1876325101810010034 ◽

2018 ◽

Vol 10 (1) ◽

pp. 34-45 ◽

Cited By ~ 1

Author(s):

Olaniyi FC ◽

Ogola JS ◽

Tshitangano TG

Keyword(s):

South Africa ◽

Waste Management ◽

South African ◽

Management Practice ◽

National Policy ◽

Medical Waste ◽

African Government ◽

The Past ◽

Government Documents ◽

Medical Waste Management

Background:Poor medical waste management has been implicated in an increase in the number of epidemics and waste-related diseases in the past years. South Africa is resource-constrained in the management of medical waste.Objectives:A review of studies regarding medical waste management in South Africa in the past decade was undertaken to explore the practices of medical waste management and the challenges being faced by stakeholders.Method:Published articles, South African government documents, reports of hospital surveys, unpublished theses and dissertations were consulted, analysed and synthesised. The studies employed quantitative, qualitative and mixed research methods and documented comparable results from all provinces.Results:The absence of a national policy to guide the medical waste management practice in the provinces was identified as the principal problem. Poor practices were reported across the country from the point of medical waste generation to disposal, as well as non-enforcement of guidelines in the provinces where they exit. The authorized disposal sites nationally are currently unable to cope with the enormous amount of the medical waste being generated and illegal dumping of the waste in unapproved sites have been reported. The challenges range from lack of adequate facilities for temporary storage of waste to final disposal.Conclusion:These challenges must be addressed and the practices corrected to forestall the adverse effects of poorly managed medical waste on the country. There is a need to develop a medical waste policy to assist in the management of such waste.

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Kerk en owerheid binne ’n regstaat. Die profetiese roeping van die kerk met betrekking tot die Suid-Afrikaanse owerheid

In die Skriflig/In Luce Verbi ◽

10.4102/ids.v34i1.589 ◽

2000 ◽

Vol 34 (1) ◽

Author(s):

N. Vorster ◽

J.H. Van Wyk

Keyword(s):

South African ◽

Fundamental Rights ◽

Theoretical Argument ◽

The South ◽

African Government ◽

Constitutional State ◽

African Context ◽

The Government ◽

Just Society ◽

The Church

Church and government within a constitutional state. The prophetic calling of the church towards the South-African government With the transition to a new political dispensation in South Africa, a constitutional state has been established. A typical characteristic of this new dispensation is that the government remains neutral while the executive powers are subject to the Bill of Human Rights. The question of how the church can realize its prophetic task towards the government within the context of a constitutional state is highlighted in this article. The central theoretical argument is that a constitutional state that acknowledges fundamental rights provides an excellent opportunity for the church to fulfil its prophetic calling within the South African context. The church can contribute to a just society by prophetic testimony within the perspective of the kingdom of God.

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