The transmission of cholera involves both direct (i.e., human-to-human) and in-
direct (i.e., environment-to-human) routes, due to the multiple interactions between
the human host, the pathogen, and the environment. In order to better understand
the complex transmission dynamics of cholera, a number of mathematical models
have been proposed and analyzed; we will briefly review some of these works in Sec-
tion 2.2. No doubt these studies have improved our knowledge of cholera dynamics.
However, the worldwide cholera outbreaks and their increasing severity, frequency
and duration in recent years underscore the gap between the complex mechanism of
cholera transmission and out current quantitative understanding and control strate~
gies for this disease.
A focus of this dissertation is to formulate optimal control models to investigate
cholera dynamics and explore control strategies that best balance the costs and gains
in fighting cholera. In doing so we will combine mathematical modeling, analysis, and
numerical simulation to seek optimal control solutions. Our results will improve the
understanding of the complex mechanism of cholera transmission, and can provide
useful guidelines to public health administration for the prevention and intervention
of cholera outbreaks. We start our discussion in Chapter 2 With a background of
optimal control, followed by a review of some representative mathematical models
of epidemic and endemic cholera. In Chapter 3, we discuss our models with optimal
controls and numerical simulations. Mathematical equations, model parameters and
diagrams are also carefully presented. In addition, we have expanded our study to
several interesting cases to better understand the disease outbreak. In Chapter 4,
we study new iterative algorithms for solving optimal control and other types of
constrained dynamical problems. Algorithms, examples, mathematical formulations
and error analysis are presented. In the last Chapter, we conclude our study and
discuss future work.