In this dissertation the potential impact of some social, cultural and economic factors on

Ebola Virus Disease (EVD) dynamics and control are studied. In Chapter two, the inability

to detect and isolate a large fraction of EVD-infected individuals before symptoms onset is

addressed. A mathematical model, calibrated with data from the 2014 West African outbreak,

is used to show the dynamics of EVD control under various quarantine and isolation

effectiveness regimes. It is shown that in order to make a difference it must reach a high

proportion of the infected population. The effect of EVD-dead bodies has been incorporated

in the quarantine effectiveness. In Chapter four, the potential impact of differential

risk is assessed. A two-patch model without explicitly incorporate quarantine is used to

assess the impact of mobility on communities at risk of EVD. It is shown that the

overall EVD burden may lessen when mobility in this artificial high-low risk society is allowed.

The cost that individuals in the low-risk patch must pay, as measured by secondary

cases is highlighted. In Chapter five a model explicitly incorporating patch-specific quarantine

levels is used to show that quarantine a large enough proportion of the population

under effective isolation leads to a measurable reduction of secondary cases in the presence

of mobility. It is shown that sharing limited resources can improve the effectiveness of

EVD effective control in the two-patch high-low risk system. Identifying the conditions

under which the low-risk community would be willing to accept the increases in EVD risk,

needed to reduce the total number of secondary cases in a community composed of two

patches with highly differentiated risks has not been addressed. In summary, this dissertation

looks at EVD dynamics within an idealized highly polarized world where resources

are primarily in the hands of a low-risk community – a community of lower density, higher

levels of education and reasonable health services – that shares a “border” with a high-risk

community that lacks minimal resources to survive an EVD outbreak.

The Visceral Leishmaniasis (VL) is primarily endemic in five countries, with India and Sudan having the highest burden. The risk factors associated with VL are either unknown in some regions or vary drastically among empirical studies. Here, a dynamical model, motivated and informed by field data from the literature, is analyzed and employed to identify and quantify the impact of region dependent risks on the VL transmission dynamics. Parameter estimation procedures were developed using model-derived quantities and empirical data from multiple resources. The dynamics of VL depend on the estimates of the control reproductive number, RC, interpreted as the average number of secondary infections generated by a single infectious individual during the infectious period. The distribution of RC was estimated for both India (with mean 2.1 ± 1.1) and Sudan (with mean 1.45 ± 0.57). This suggests that VL can be established in naive regions of India more easily than in naive regions of Sudan. The parameter sensitivity analysis on RC suggests that the average biting rate and transmission probabilities between host and vector are among the most sensitive parameters for both countries. The comparative assessment of VL transmission dynamics in both India and Sudan was carried out by parameter sensitivity analysis on VL-related prevalences (such as prevalences of asymptomatic hosts, symptomatic hosts, and infected vectors). The results identify that the treatment and symptoms’ developmental rates are parameters that are highly sensitive to VL symptomatic and asymptomatic host prevalence, respectively, for both countries. It is found that the estimates of transmission probability are significantly different between India (from human to sandflies with mean of 0.39 ± 0.12; from sandflies to human with mean 0.0005 ± 0.0002) and Sudan (from human to sandflies with mean 0.26 ± 0.07; from sandflies to human with mean 0.0002 ± 0.0001). The results have significant implications for elimination. An increasing focus on elimination requires a review of priorities within the VL control agenda. The development of systematic implementation of con­trol programs based on identified risk factors (such as monitoring of asymptomatically infected individuals) has a high transmission-blocking potential.