Spatial analysis of Schistosoma Haematobium infection among school children in a rural sub-district of South Africa: an application of geographical information systems (2009)
Date
2009-11-24T09:58:38Z
Authors
Azongo, Kwaku Daniel
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Background
Assessing risk of schistosomiasis requires knowledge of the spatial distribution of the disease and its
association with demographic, socioeconomic, behavioural, and environmental factors over time and
space. The objective of this study was to advance such knowledge by analyzing the spatial
distribution of schistosoma haematobium infections in relation to the demographic attributes and
environmental covariates of the Africa centre Demographic Surveillance Areas (DSA) in rural
KwaZulu-Natal. The study also examined the association between household socio-economic
conditions and rates of S. haematobium infection with particular emphasis on the impact of pipe
water on rates of infection.
Methods
The study is a crosses sectional study, involving all 33 primary schools in Africa Centre DSA. 2110
grade five and six children took part in the study. Statistical analysis was done using chi square tests
to compare statistical significant differences between sex and age groups. Bivariate and multivariate
logistic regression models were used to explore factors that are significantly associated with
infection. Spatial analysis was done to examine the spatial distribution of the disease using
geographical information systems techniques. Microscopic analysis of the urine samples was done
using the filtration technique.
Results
Of the 2110 school children who were screened for infection, 347 tested positive for the presence of
iv
S. haematobium, representing an overall prevalence of 16.6%. Prevalence levels were higher in boys
(20.8%) than females (8.5%) (P<0.001). 57.6% were heavily infected (eggs ≥50 eggs per 10ml
urine) as compared to 42.5% who had light infection (eggs<50 eggs/10ml of urine). Whereas,
prevalence was significantly age-dependent (Pearson chi2 (3) = 28.4184, P< 0.001), intensity of
infection was not significantly age dependent (Pearson chi2 (3) = 3.2579, P<0.354). Altitudinal
variation, access to portable water, toilet, and distance to water bodies were significantly associated
with infection. Prevalence of infection was clustered around the Eastern part of the study area.
Conclusion
While there may be several factors associated with schistosoma infection in the study area's school
children; age, sex, water contact behaviour, homestead altitude and distance to permanent water
bodies, were the most significant risk factors explaining the spatial distribution of S. haematobium
infection in the Africa Centre DSA. Selective Mass treatment of S. haematobium infection in 7
clustered areas is recommended for the control of the disease.
Description
M.Sc. (Med.), Faculty of Health Sciences, University of the Witwatersrand, 2009
Keywords
Schistosoma Haematobium, bilharzia, geographical information, epidemiology