Hydrology, Climate and Water-Borne Disease Transmission: Role of Large Scale Hydroclimatology in Cholera Dynamics of Bengal Delta.
Abstract: With the
ever-expanding geographic reach of the seventh cholera pandemic and alarming fatality
rates in newly affected regions, it is apparent that global cholera prevention
strategies warrant rethinking. The striking seasonality and annual recurrence of this
infectious disease in endemic areas remain of considerable interest to scientists,
epidemiologists, and public health workers. ... read moreThis interdisciplinary research study
attempts to identify the hydroclimatic and environmental drivers of cholera dynamics,
and the role of underlying large-scale processes in propagating the disease in different
seasons and spatial locations that have sufficient temporal and spatial "memory" to
allow the development of an early warning system. In this study, it is shown that
cholera outbreaks in the Bengal Delta region, also known as the native homeland of
cholera, are propagated from the coastal to the inland floodplain areas and from spring
to fall by two distinctly different, pre- and post-monsoon, transmission cycles
influenced by coastal and terrestrial hydroclimatic processes, respectively. Seasonal
and interannual patterns of cholera transmission are strongly influenced by estuarine
salinity and inland flood inundation patterns that may set the ecological and
environmental `stage' for epidemic outbreaks over large geographic regions. A coupled
hydroclimatology-epidemiology model was developed to provide a framework for assessing
the impact of hydroclimatic and environmental forcings on cholera dynamics; and has the
potential to provide public health authorities a necessary spatially explicit early
warning for preemptive intervention before epidemic cholera outbreaks and extreme
climatic events such as droughts and floods, especially in light of changing climate
patterns in the Bengal Delta region.
Thesis (Ph.D.)--Tufts University, 2011.
Submitted to the Dept. of Civil Engineering.
Advisor: Shafiqul Islam.
Committee: Rita Colwell, Elfatih Eltahir, and David Gute.
Keywords: Hydrologic sciences, Environmental engineering, and Civil engineering.read less