The two hyper–endemic regions for Visceral Leishmaniasis (VL) in the world are located in India and Sudan. These two countries account for more than half of the world's VL burden. The regional risk factors associated with VL vary drastically per region. A mathematical model of VL transmission dynamics is introduced and parametrized to quantify risk of VL infection in India and Sudan via a careful analysis of VL prevalence level and the control reproductive number, Rc, a metric often used to characterize the degree of endemicity. Parameters, associated with VL-epidemiology for India and Sudan, are estimated using data from health departmental reports, clinical trials, field studies, and surveys in order to assess potential differences between the hyper--endemic regions of India and Sudan. The estimated value of reproduction number for India is found to be 60% higher than that of Sudan (Rc(India)= 2.1 and Rc(Sudan)= 1.3). It is observed that the Rc is most sensitive to the average biting rate and vector-human transmission rates irrespective of regional differences. The treatment rate is found to be the most sensitive parameter to VL prevalence in humans for both India and Sudan. Although the unexplained higher incidence of VL in India needs to be carefully monitored during long-term empirical follow-up, the risk factors associated with vectors are identified as more critical to dynamics of VL than factors related to humans through this modeling study.