Global stability and optimal control analysis of a foot-and-mouth disease model with vaccine failure and environmental transmission

2020 ◽  
Vol 132 ◽  
pp. 109568 ◽  
Author(s):  
Tinashe B. Gashirai ◽  
Senelani D. Musekwa-Hove ◽  
Paride O. Lolika ◽  
Steady Mushayabasa
Keyword(s):  
Optimal Control ◽  
Global Stability ◽  
Disease Model ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Control Analysis ◽  
Vaccine Failure ◽  
Environmental Transmission ◽  
Foot And Mouth

scholarly journals Parameter-dependent transmission dynamics and optimal control of foot and mouth disease in a contaminated environment

2019 ◽  
Vol 27 (1) ◽  
Author(s):  
Francis Mugabi ◽  
Joseph Mugisha ◽  
Betty Nannyonga ◽  
Henry Kasumba ◽  
Margaret Tusiime
Keyword(s):  
Optimal Control ◽  
Deterministic Model ◽  
Foot And Mouth Disease ◽  
Decay Rates ◽  
Mouth Disease ◽  
Control Measures ◽  
Transmission Dynamics ◽  
Optimality System ◽  
Foot And Mouth ◽  
Environmental Decontamination

AbstractThe problem of foot and mouth disease (FMD) is of serious concern to the livestock sector in most nations, especially in developing countries. This paper presents the formulation and analysis of a deterministic model for the transmission dynamics of FMD through a contaminated environment. It is shown that the key parameters that drive the transmission of FMD in a contaminated environment are the shedding, transmission, and decay rates of the virus. Using numerical results, it is depicted that the host-to-host route is more severe than the environmental-to-host route. The model is then transformed into an optimal control problem. Using the Pontryagin’s Maximum Principle, the optimality system is determined. Utilizing a gradient type algorithm with projection, the optimality system is solved for three control strategies: optimal use of vaccination, environmental decontamination, and a combination of vaccination and environmental decontamination. Results show that a combination of vaccination and environmental decontamination is the most optimal strategy. These results indicate that if vaccination and environmental decontamination are used optimally during an outbreak, then FMD transmission can be controlled. Future studies focusing on the control measures for the transmission of FMD in a contaminated environment should aim at reducing the transmission and the shedding rates, while increasing the decay rate.

Dynamical analysis of a fractional-order foot-and-mouth disease model

2021 ◽  
Vol 15 (1) ◽  
pp. 65-82
Author(s):  
Tinashe B. Gashirai ◽  
Senelani D. Hove-Musekwa ◽  
Steady Mushayabasa
Keyword(s):  
Fractional Order ◽  
Disease Model ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Dynamical Analysis ◽  
Foot And Mouth

scholarly journals Post-outbreak surveillance strategies to support proof of freedom from foot-and-mouth disease

2021 ◽  
Author(s):  
Richard Bradhurst ◽  
Graeme Garner ◽  
Iain East ◽  
Clare Death ◽  
Aaron Dodd ◽  
...  
Keyword(s):  
Disease Model ◽  
Foot And Mouth Disease ◽  
Control Program ◽  
Mouth Disease ◽  
Surveillance Program ◽  
Statistical Confidence ◽  
Foot And Mouth ◽  
The Face ◽  
Sampling Regime ◽  
The Cost

AbstractWhilst emergency vaccination may help contain foot-and-mouth disease in a previously FMD-free country, its use complicates post-outbreak surveillance and the recovery of FMD-free status. A structured surveillance program is required that can distinguish between vaccinated and residually infected animals, and provide statistical confidence that the virus is no longer circulating in previously infected areas.Epidemiological models have been well-used to investigate the potential benefits of emergency vaccination during a control progam and when/where/whom to vaccinate in the face of finite supplies of vaccine and personnel. Less well studied are post-outbreak issues such as the management of vaccinated animals and the implications of having used vaccination during surveillance regimes to support proof-of-freedom. This paper presents enhancements to the Australian Animal Disease Model (AADIS) that allow comparisons of different post-outbreak surveillance sampling regimes for establishing proof-of-freedom from FMD.A case study is provided that compares a baseline surveillance sampling regime (derived from current OIE guidelines), with an alternative less intensive sampling regime. It was found that when vaccination was not part of the control program, a reduced sampling intensity significantly reduced the number of samples collected and the cost of the post-outbreak surveillance program, without increasing the risk of missing residual infected herds.

scholarly journals Quantifying the Transmission of Foot-and-Mouth Disease Virus in Cattle via a Contaminated Environment

mBio ◽  
2020 ◽  
Vol 11 (4) ◽  
Author(s):  
Claire Colenutt ◽  
Emma Brown ◽  
Noel Nelson ◽  
David J. Paton ◽  
Phaedra Eblé ◽  
...  
Keyword(s):  
Disease Virus ◽  
Clinical Signs ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Control Measures ◽  
Effective Control ◽  
Environmental Transmission ◽  
Indirect Transmission ◽  
Mouth Disease Virus ◽  
Foot And Mouth

ABSTRACT Indirect transmission via a contaminated environment can occur for a number of pathogens, even those typically thought of as being directly transmitted, such as influenza virus, norovirus, bovine tuberculosis, or foot-and-mouth disease virus (FMDV). Indirect transmission facilitates spread from multiple sources beyond the infectious host, complicating the epidemiology and control of these diseases. This study carried out a series of transmission experiments to determine the dose-response relationship between environmental contamination and transmission of FMDV in cattle from measurements of viral shedding and rates of environmental contamination and survival. Seven out of ten indirect exposures resulted in successful transmission. The basic reproduction number for environmental transmission of FMDV in this experimental setting was estimated at 1.65, indicating that environmental transmission alone could sustain an outbreak. Importantly, detection of virus in the environment prior to the appearance of clinical signs in infected cattle and successful transmission from these environments highlights there is a risk of environmental transmission even before foot-and-mouth disease (FMD) is clinically apparent in cattle. Estimated viral decay rates suggest that FMDV remained viable in this environment for up to 14 days, emphasizing the requirement for stringent biosecurity procedures following outbreaks of FMD and the design of control measures that reflect the biology of a pathogen. IMPORTANCE Effective control of a disease relies on comprehensive understanding of how transmission occurs, in order to design and apply effective control measures. Foot-and-mouth disease virus (FMDV) is primarily spread by direct contact between infected and naive individuals, although the high levels of virus shed by infected animals mean that virus can also be spread through contact with contaminated environments. Using a series of transmission experiments, we demonstrate that environmental transmission alone would be sufficient to sustain an outbreak. Key observations include that a risk of transmission exists before clinical signs of foot-and-mouth disease (FMD) are apparent in cattle and that survival of virus in the environment extends the transmission risk period. This study highlights the role a contaminated environment can play in the transmission of FMDV and presents approaches that can also be applied to study the transmission of other pathogens that are able to survive in the environment.

scholarly journals Airborne spread of foot-and-mouth disease – Model intercomparison

2010 ◽  
Vol 183 (3) ◽  
pp. 278-286 ◽  
Author(s):  
John Gloster ◽  
Andrew Jones ◽  
Alison Redington ◽  
Laura Burgin ◽  
Jens H. Sørensen ◽  
...  
Keyword(s):  
Disease Model ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Model Intercomparison ◽  
Foot And Mouth

Foot and mouth disease model verification and ‘relative validation’ through a formal model comparison

2011 ◽  
Vol 30 (2) ◽  
pp. 527-540 ◽  
Author(s):  
R.L. SANSON ◽  
N. HARVEY ◽  
M.G. GARNER ◽  
M.A. STEVENSON ◽  
T.M. DAVIES ◽  
...  
Keyword(s):  
Model Comparison ◽  
Formal Model ◽  
Disease Model ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Model Verification ◽  
Foot And Mouth

scholarly journals Lyapunov Stability Analysis of a Delayed Foot-and-Mouth Disease Model with Animal Vaccination

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Tinashe B. Gashirai ◽  
Senelani D. Hove-Musekwa ◽  
Steady Mushayabasa
Keyword(s):  
Disease Virus ◽  
Disease Model ◽  
Intervention Strategy ◽  
Ecological Factors ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Sub Saharan Africa ◽  
Epidemic Dynamics ◽  
Mouth Disease Virus ◽  
Foot And Mouth

Foot-and-mouth disease virus remains one of the most important livestock diseases in sub-Saharan Africa and several Southeast Asian countries. Vaccination of livestock has been recognized as an important tool for the control of foot-and-mouth disease virus. However, this intervention strategy has some limitations. Generally, vaccine production is a complex multistep process which involves development, manufacturing, and delivery processes, and through this extensive process, some challenges such as poor vaccine storage often arise. More often, these challenges alter the validity of the vaccination. Foot-and-mouth disease virus epidemic dynamics have been extensively explored, but understanding the role of vaccination validity on virus endemicity is lacking. We present a time-delayed foot-and-mouth disease model that incorporates relevant biological and ecological factors, vaccination effects, and disease carriers. We determined the basic reproduction number and demonstrated that it is an important metric for persistence and extinction of the disease in the community. Numerical illustrations were utilised to support some of the analytical results.

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