Infection dynamics of Newcastle disease in the central zone of Tanzania under optimal control measure

Poultry production in Tanzania has been recognised to play a vital role in Gross Domestic Product (GDP). Chickens, in particular, contribute a significant endowment to the gross national economy. Chickens help to improve socioeconomic, survival, growth and development in many rural communities in Tanzania. However, the Newcastle disease (ND) which affects mostly chicken considered as the most threatening disease and destabilizes the poultry production system. This work presents a mathematical dynamics of ND with Holling Type II functional response which was rigorously analyzed using the theory of ordinary differential equation. The model fitting and parameter estimation were evaluated using Markov Chain Monte Carlo (MCMC) simulations for the data from Kongwa, Chamwino, Ikungi, Singida Rural and Mkalama districts in Dodoma and Singida regions. The time-dependent control of ND has been analyzed with three possible control strategies namely: chicken vaccination, human education campaign and treatment of an infected human. The optimal control results of ND show that whenever chicken vaccination strategy is applied either alone or with any other strategy reveals a significant difference in controlling the disease in chicken. Cost-effectiveness analysis was evaluated and found out that the combination of chicken vaccination and human education campaign strategy as most cost-effective. Therefore, the ministry of livestock and fisheries in Tanzania through regional, district, division, ward and village veterinary officers are strongly advised to take extra incentives in ensuring that all chickens are vaccinated properly and timely, and also advised to provide an adequate education for poultry farmers.