Optimal Control Applied to a Fractional-Order Foot-and-Mouth Disease Model

Author(s):  
Tinashe B. Gashirai ◽  
Senelani D. Hove-Musekwa ◽  
Steady Mushayabasa
2021 ◽  
Vol 15 (1) ◽  
pp. 65-82
Author(s):  
Tinashe B. Gashirai ◽  
Senelani D. Hove-Musekwa ◽  
Steady Mushayabasa

Author(s):  
Francis Mugabi ◽  
Joseph Mugisha ◽  
Betty Nannyonga ◽  
Henry Kasumba ◽  
Margaret Tusiime

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.


2021 ◽  
Author(s):  
Richard Bradhurst ◽  
Graeme Garner ◽  
Iain East ◽  
Clare Death ◽  
Aaron Dodd ◽  
...  

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.


2010 ◽  
Vol 183 (3) ◽  
pp. 278-286 ◽  
Author(s):  
John Gloster ◽  
Andrew Jones ◽  
Alison Redington ◽  
Laura Burgin ◽  
Jens H. Sørensen ◽  
...  

2011 ◽  
Vol 30 (2) ◽  
pp. 527-540 ◽  
Author(s):  
R.L. SANSON ◽  
N. HARVEY ◽  
M.G. GARNER ◽  
M.A. STEVENSON ◽  
T.M. DAVIES ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Tinashe B. Gashirai ◽  
Senelani D. Hove-Musekwa ◽  
Steady Mushayabasa

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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