Use of a mathematical model to study the dynamics ofCtenocephalides felispopulations in the home environment and the impact of various control measures

AbstractRift Valley fever (RVF) is an emerging, zoonotic, arboviral haemorrhagic fever threatening livestock and humans mainly in Africa. RVF is of global concern, having expanded its geographical range over the last decades. The impact of control measures on epidemic dynamics using empirical data has not been assessed. Here, we combined seroprevalence livestock and human RVF case data from the 2018-2019 epidemic in Mayotte, with a dynamic mathematical model. Using a Bayesian inference framework, we estimated viral transmission potential amongst livestock, and spillover from livestock to humans, through both direct contact and vector-mediated routes. Model simulations were used to assess the impact of vaccination on reducing the human epidemic size. Reactive vaccination immunising 20% of the livestock population reduced the number of human cases by 30%. To achieve a similar impact, delaying the vaccination by one month required using 50% more vaccine doses, and vaccinating only humans required 20 times as more as the number of doses for livestock. Finally, with 53.92% (95%CrI [44.76-61.29]) of livestock estimated to be immune at the end of the epidemic wave, viral re-emergence in the next rainy season (2019-2020) was unlikely. We present the first mathematical model for RVF fitted to real-world data to estimate virus transmission parameters, and able to inform potential control programmes. Human and animal health surveillance, and timely livestock vaccination appear to be key in reducing disease risk in humans. We furthermore demonstrate the value of a One Health quantitative approach to surveillance and control of zoonotic infectious diseases.

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Impact of mass testing during an epidemic rebound of SARS-CoV-2: A modelling study

10.1101/2020.12.08.20246009 ◽

2020 ◽

Author(s):

Paolo Bosetti ◽

Cécile Tran Kiem ◽

Yazdan Yazdanpanah ◽

Arnaud Fontanet ◽

Bruno Lina ◽

...

Keyword(s):

Mathematical Model ◽

Control Measures ◽

The Impact ◽

Silver Bullet ◽

Modelling Study

We used a mathematical model to evaluate the impact of mass testing in the control of SARS-CoV-2. Conditions required to control a quickly growing epidemic with mass testing appear impossible to achieve. Mass testing should therefore not be seen as a silver bullet that will ensure other control measures can be removed. Even under a set of optimistic assumptions, this strategy is most relevant when epidemic growth remains limited, thanks to a combination of interventions.

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Assessment of the Impacts of Pharmaceutical and Non-pharmaceutical Intervention on COVID-19 in South Africa Using Mathematical Model

10.1101/2020.11.13.20231159 ◽

2020 ◽

Author(s):

Rabiu Musa ◽

Absalom E. Ezugwu ◽

Godwin C. E. Mbah

Keyword(s):

South Africa ◽

Mathematical Model ◽

Health Hazard ◽

Control Measures ◽

World Health ◽

The Novel ◽

Pharmaceutical Intervention ◽

Social Distancing ◽

The Impact ◽

Different Levels

AbstractThe novel coronal virus has spread across more than 213 countries within the space of six months causing devastating public health hazard and monumental economic loss. In the absence of clinically approved pharmaceutical intervention, attentions are shifted to non-pharmaceutical controls to mitigate the burden of the novel pandemic. In this regard, a ten mutually exclusive compartmental mathematical model is developed to investigate possible effects of both pharmaceutical and non-pharmaceutical controls incorporating both private and government’s quarantine and treatments. Several reproduction numbers were calculated and used to determine the impact of both control measures as well as projected benefits of social distancing, treatments and vaccination. We investigate and compare the possible impact of social distancing incorporating different levels of vaccination, with vaccination programme incorporating different levels of treatment. Using the officially published South African COVID-19 data, the numerical simulation shows that the community reproduction threshold will be 30 when there is no social distancing but will drastically reduced to 5 (about 83% reduction) when social distancing is enforced. Furthermore, when there is vaccination with perfect efficacy, the community reproduction threshold will be 4 which increases to 12 (about 67% increment) with-out vaccination. We also established that the implementation of both interventions is enough to curtail the spread of COVID-19 pandemic in South Africa which is in confirmation with the recommendation of the world health organization.

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Impact of mass testing during an epidemic rebound of SARS-CoV-2: a modelling study using the example of France

Eurosurveillance ◽

10.2807/1560-7917.es.2020.26.1.2001978 ◽

2021 ◽

Vol 26 (1) ◽

Author(s):

Paolo Bosetti ◽

Cécile Tran Kiem ◽

Yazdan Yazdanpanah ◽

Arnaud Fontanet ◽

Bruno Lina ◽

...

Keyword(s):

Mathematical Model ◽

Severe Acute Respiratory Syndrome ◽

Control Measures ◽

Frequent Testing ◽

The Impact ◽

Modelling Study

We used a mathematical model to evaluate the impact of mass testing in the control of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Under optimistic assumptions, one round of mass testing may reduce daily infections by up to 20–30%. Consequently, very frequent testing would be required to control a quickly growing epidemic if other control measures were to be relaxed. Mass testing is most relevant when epidemic growth remains limited through a combination of interventions.

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Role of Mathematical Model in Curbing COVID-19 in Nigeria

Communication in Biomathematical Sciences ◽

10.5614/cbms.2020.3.2.5 ◽

2021 ◽

Vol 3 (2) ◽

pp. 135-147

Author(s):

Chinwendu Emilian Madubueze ◽

Nkiru Maria Akabuike ◽

Sambo Dachollom

Keyword(s):

Mathematical Model ◽

Basic Reproduction Number ◽

Reproduction Number ◽

Viral Disease ◽

Control Measures ◽

Social Distancing ◽

Testing Rate ◽

Intervention Measures ◽

The Impact ◽

The Basic Reproduction Number

COVID-19 is a viral disease that is caused by Severe Acute Respiratory Syndrome coronavirus 2 (SARSCoV-2) which has no approved vaccine. Based on the available non-pharmacological interventions like wearing of face masks, observing social distancing, and lockdown, this work assesses the impact of non-pharmaceutical control measures (social distancing and use of face-masks) and mass testing on the transmission of COVID-19 in Nigeria. A mathematical model for COVID-19 is formulated with intervention measures (observing social distancing and wearing of face masks) and mass testing. The basic reproduction number, R_0, is computed using next-generation method while the disease-free equilibrium is found to be locally and globally asymptotically stable when R_0< 1. The model is parameterized using Nigeria data on COVID-19 in Nigeria. The basic reproduction number is found to be less than unity (R_0 < 1) either when the compliance with intervention measures is moderate (50% <= alpha< 70%) and the testing rate per day is moderate (0,5 <=alpha_2 < 0,7) or when the compliance with intervention measures is strict (alpha>=70%) and the testing rate per day is poor (alpha_2 = 0,3). This implies that Nigeria will be able to halt the spread of COVID-19 under these two conditions. However, it will be easier to enforce strict compliance with intervention measures in the presence of poor testing rate due to the limited availability of testing facilities and manpower in Nigeria. Hence, this study advocates that Nigerian governments (Federal and States) should aim at achieving a testing rate of at least 0.3 per day while ensuring that all the citizens strictly comply with wearing face masks and observing social distancing in public.

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The 2020 SARS-CoV-2 epidemic in England: key epidemiological drivers and impact of interventions

10.1101/2021.01.11.21249564 ◽

2021 ◽

Author(s):

Edward S. Knock ◽

Lilith K. Whittles ◽

John A. Lees ◽

Pablo N. Perez-Guzman ◽

Robert Verity ◽

...

Keyword(s):

Mathematical Model ◽

Reproduction Number ◽

Clinical Care ◽

Herd Immunity ◽

The Elderly ◽

Surveillance Data ◽

Control Measures ◽

Care Homes ◽

The Impact ◽

Regional Surveillance

AbstractWe fitted a model of SARS-CoV-2 transmission in care homes and the community to regional surveillance data for England. Among control measures implemented, only national lockdown brought the reproduction number below 1 consistently; introduced one week earlier it could have reduced first wave deaths from 36,700 to 15,700 (95%CrI: 8,900–26,800). Improved clinical care reduced the infection fatality ratio from 1.25% (95%CrI: 1.18%–1.33%) to 0.77% (95%CrI: 0.71%–0.84%). The infection fatality ratio was higher in the elderly residing in care homes (35.9%, 95%CrI: 29.1%–43.4%) than those residing in the community (10.4%, 95%CrI: 9.1%–11.5%). England is still far from herd immunity, with regional cumulative infection incidence to 1st December 2020 between 4.8% (95%CrI: 4.4%–5.1%) and 15.4% (95%CrI: 14.9%–15.9%) of the population.One-sentence summaryWe fit a mathematical model of SARS-CoV-2 transmission to surveillance data from England, to estimate transmissibility, severity, and the impact of interventions

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Estimating the impact of lock-down, quarantine and sensitization in a COVID-19 outbreak: lessons from the COVID-19 outbreak in China

PeerJ ◽

10.7717/peerj.9933 ◽

2020 ◽

Vol 8 ◽

pp. e9933

Author(s):

Obiora C. Collins ◽

Kevin J. Duffy

Keyword(s):

Infectious Disease ◽

Mathematical Model ◽

Disease Outbreaks ◽

Real Data ◽

Control Measures ◽

Recent History ◽

Dominant Effect ◽

Infectious Disease Outbreaks ◽

Secondary Infections ◽

The Impact

In recent history, COVID-19 is one of the worst infectious disease outbreaks currently affecting humanity globally. Using real data on the COVID-19 outbreak from 22 January 2020 to 30 March 2020, we developed a mathematical model to investigate the impact of control measures in reducing the spread of the disease. Analyses of the model were carried out to determine the dynamics. The results of the analyses reveal that, using the data from China, implementing all possible control measures best reduced the rate of secondary infections. However, quarantine (isolation) of infectious individuals is shown to have the most dominant effect. This possibility emphasizes the need for extensive testing due to the possible prevalence of asymptomatic COVID-19 cases.

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The methodological approach for the determination of the pressure of artificial raindrops as a question of the theory of splash soil erosion

Melioration and Water Management ◽

10.32962/0235-2524-2019-1-24-28 ◽

2020 ◽

pp. 24-28

Author(s):

Mihail Zver'kov

Keyword(s):

Block Diagram ◽

Methodological Approach ◽

Control Measures ◽

Soil Conditions ◽

Effective Pressure ◽

Long Distance ◽

Splash Erosion ◽

Rain Drops ◽

Artificial Rain ◽

The Impact

To the article the results of the theoretical and experimental researches are given on questions of estimates of the dynamic rate effect of raindrop impact on soil. The aim of this work was to analyze the current methods to determine the rate of artificial rain pressure on the soil for the assessment of splash erosion. There are the developed author’s method for calculation the pressure of artificial rain on the soil and the assessment of splash erosion. The study aims to the justification of evaluation methods and the obtaining of quantitative characteristics, prevention and elimination of accelerated (anthropogenic) erosion, the creation and the realization of the required erosion control measures. The paper considers the question of determining the pressure of artificial rain on the soil. At the moment of raindrops impact, there is the tension in the soil, which is called vertical effective pressure. It is noted that the impact of rain drops in the soil there are stresses called vertical effective pressure. The equation for calculation of vertical effective pressure is proposed in this study using the known spectrum of raindrops. Effective pressure was 1.4 Pa for the artificial rain by sprinkler machine «Fregat» and 5.9 Pa for long distance sprinkler DD-30. The article deals with a block diagram of the sequence for determining the effective pressure of rain drops on the soil. This diagram was created by the author’s method of calculation of the effective pressure of rain drops on the soil. The need for an integrated approach to the description of the artificial rain impact on the soil is noted. Various parameters characterizing drop erosion are considered. There are data about the mass of splashed soil in the irrigation of various irrigation machinery and installations. For example, the rate (mass) of splashed soil was 0.28…0.78 t/ha under irrigation sprinkler apparatus RACO 4260–55/701C in the conditions of the Ryazan region. The method allows examining the environmental impact of sprinkler techniques for analyzes of the pressure, caused by raindrops, on the soil. It can also be useful in determining the irrigation rate before the runoff for different types of sprinkler equipment and soil conditions.

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The Impact of Light Polarisation on Light Field of Scenes with Multiple Reflections

Light & Engineering ◽

10.33383/2019-023 ◽

2020 ◽

pp. 108-115 ◽

Cited By ~ 1

Author(s):

Vladimir P. Budak ◽

Anton V. Grimaylo

Keyword(s):

Mathematical Model ◽

Light Field ◽

Global Illumination ◽

Multiple Reflections ◽

Software Environment ◽

The Monte Carlo Method ◽

Mueller Matrices ◽

Volume Integration ◽

The Impact

The article describes the role of polarisation in calculation of multiple reflections. A mathematical model of multiple reflections based on the Stokes vector for beam description and Mueller matrices for description of surface properties is presented. On the basis of this model, the global illumination equation is generalised for the polarisation case and is resolved into volume integration. This allows us to obtain an expression for the Monte Carlo method local estimates and to use them for evaluation of light distribution in the scene with consideration of polarisation. The obtained mathematical model was implemented in the software environment using the example of a scene with its surfaces having both diffuse and regular components of reflection. The results presented in the article show that the calculation difference may reach 30 % when polarisation is taken into consideration as compared to standard modelling.

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Characterizing the effectiveness of COVID-19 mitigation measures: A data-centric approach (Preprint)

10.2196/preprints.21321 ◽

2020 ◽

Author(s):

Lukman Olagoke ◽

Ahmet E. Topcu

Keyword(s):

Control Measure ◽

Control Measures ◽

World Health ◽

Mitigation Measures ◽

Effective Control ◽

The World ◽

Decision Making Processes ◽

And Performance ◽

Health Organization ◽

The Impact

BACKGROUND COVID-19 represents a serious threat to both national health and economic systems. To curb this pandemic, the World Health Organization (WHO) issued a series of COVID-19 public safety guidelines. Different countries around the world initiated different measures in line with the WHO guidelines to mitigate and investigate the spread of COVID-19 in their territories. OBJECTIVE The aim of this paper is to quantitatively evaluate the effectiveness of these control measures using a data-centric approach. METHODS We begin with a simple text analysis of coronavirus-related articles and show that reports on similar outbreaks in the past strongly proposed similar control measures. This reaffirms the fact that these control measures are in order. Subsequently, we propose a simple performance statistic that quantifies general performance and performance under the different measures that were initiated. A density based clustering of based on performance statistic was carried out to group countries based on performance. RESULTS The performance statistic helps evaluate quantitatively the impact of COVID-19 control measures. Countries tend show variability in performance under different control measures. The performance statistic has negative correlation with cases of death which is a useful characteristics for COVID-19 control measure performance analysis. A web-based time-line visualization that enables comparison of performances and cases across continents and subregions is presented. CONCLUSIONS The performance metric is relevant for the analysis of the impact of COVID-19 control measures. This can help caregivers and policymakers identify effective control measures and reduce cases of death due to COVID-19. The interactive web visualizer provides easily digested and quick feedback to augment decision-making processes in the COVID-19 response measures evaluation. CLINICALTRIAL Not Applicable

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