Download UROGENITAL SCHISTOSOMIASIS IN RURAL GHANA MAPPING RISK FACTORS FOR Background Methods

MAPPING RISK FACTORS FOR
UROGENITAL SCHISTOSOMIASIS IN RURAL GHANA
Background
Urogenital schistosomiasis (UGS) is a neglected
tropical disease endemic to sub-Saharan Africa,
particularly rural areas with poor water and
sanitation coverage. Transmission of the parasite is characterized by a complex life cycle involving the fresh water snail as an intermediate
host, and occurs through skin contact with contaminated surface water. Individual risk factors
include swimming and domestic water use. Control methods generally involve mass drug administration (MDA), water and sanitation improvements, and environmental alterations.
Methods
There is a lack of UGS prevalence data worldwide, resulting in the limited ability to predict
hotspots. The last prevalence update of UGS in
Ghana occurred in the mid-1980s. Despite recent advances in predictive mapping, these
maps have not included community-level risk
factors that account for UGS as a focal disease,
and they suffer from limited validation. This
analysis is limited to the Eastern Region of Ghana.
This analysis extrapolated risk factor information from 75 towns for which detailed information is
available to 15-minute clinic catchment areas in the entire study area to predict risk of UGS. Risk factors, including water quality problems, low water infrastructure coverage (boreholes and hand dug
wells), high endemic town density , and exposure to surface water were summed to show prediction
of UGS risk. These results can be visually compared to clinic-reported UGS prevalence.
Hand Dug Well Density
Water Quality
Quantiles of risk of having at
least one water quality problem (particles, scent, oil, salt
and staining), normalized by
population in each 15-minute
clinic catchment area.
Quantiles of the number of
hand dug wells, normalized by
population in each 15-minute
clinic catchment area.
Risk Factor Sum
Endemic Town Density
Borehole Density
Quantiles of the number of
towns classified by Ghana
Health Service as endemic,
normalized by population in
each 15-minute clinic catchment area.
Comparison: Clinic-Reported UGS Prevalence
Quantiles of the number of
boreholes, normalized by population in each 15-minute
clinic catchment area.
Surface Water Exposure
Cartographers: Alexandra Kulinkina and Ariel Branz
Quantiles of percentage of the
population within 250 meters
of a river in each 15-minute
clinic catchment area.
Alexandra Kulinkina and Ariel Branz
UEP 294
December 12, 2014