Community based methods for schistosomiasis prediction and sustainable control in Ghana
Urogenital schistosomiasis is a tropical disease transmitted through skin contact with
rivers, lakes, ponds and streams that are contaminated with human waste and harbor
specific aquatic snail species. Schistosomiasis is a disease of poverty with 97% of the
burden concentrated in sub-Saharan Africa; school aged children being the most at risk
group. The predominant control strategy ... read morein endemic African countries is preventive
chemotherapy; however, the need to combine this intervention with primary prevention
measures such as water and sanitation improvements is gaining recognition. In this
thesis, data from multiple field surveys of water-related conditions are employed in
combination with remote sensing data to explore environmental and behavioral drivers of
schistosomiasis transmission in rural Ghanaian communities. A particular focus is on the
dynamic use patterns of safe groundwater sources and infectious surface water bodies.
Some of the factors that negatively affect safe water use are seasonal availability,
functionality, price of water, and water quality. Furthermore, how users perceive water
quality is potentially more important in the context of schistosomiasis transmission as
compared to its actual safety. For example, elevated iron and hardness concentrations,
while not harmful to health, deter people from using safe groundwater sources, thereby
increasing schistosomiasis risk. Environmental parameters did not have a significant
bearing on schistosomiasis risk because a relatively homogeneous geographic region was
selected for the study. However, the present work showed that knowledge of specific
water contact sites, which can be gained through field data collection, increases the
capacity of remote sensing variables to predict schistosomiasis risk. The major
conclusion of the thesis is that reliance on contaminated ponds and streams for meeting
daily water needs in the rural Eastern Region of Ghana contributes to high reinfection
rates, severely limiting the efficacy and sustainability of chemotherapy with
praziquantel. In order to reduce local transmission, the reasons underlying people's
continued use of unsafe water sources in the presence of safe sources need to be
addressed. In the meantime, drug treatment should be more specifically targeted on a
community basis in terms of frequency and
Thesis (Ph.D.)--Tufts University, 2017.
Submitted to the Dept. of Civil Engineering.
Advisor: Elena Naumova.
Committee: Jeanine Plummer, Patrick Webb, Karen Kosinski, and David Gute.
Keywords: Environmental health, and Epidemiology.read less