Biostatistical Analysis of the Schistosomiasis Control Initiative Programme on Schistosoma Prevalence, Intensity and Associated Morbidity

Abstract

Background: Schistosomiasis remains one of the most prevalent parasitic diseases in developing countries. Goal and objectives: The potential relationship between Schistosoma mansoni and anaemia, was examined using Schistosomiasis Control Initiative (SCI) data on Ugandan children and a randomized clinical trial implemented by colleagues from the London School of Hygiene and Tropical Medicine (LSHTM) in Western Kenya. The impact of large-scale administration of chemotherapy on Schistosoma haematobium infection and associated morbidity was also evaluated using SCI data on Burkinabe children. Evaluation and validation of field applicable tools, such as ultrasound, for the cost-effective diagnosis of schistosomiasis morbidity using SCI baseline data from Malian children was another aim of this thesis. Furthermore, in combination with the ultrasound scans, microscopic examination of urine for detection of S. haematobium eggs, dipsticks for detection of haematuria, tests for circulating antigens and serology tests were examined for the cost-effective assessment of S. haematobium prevalence in an adult’s dataset from Ghana. Methods: Biostatistical analysis of afore mentioned data was applied. Principal findings: Results from SCI and LSHTM studies suggest that anaemia is associated with schistosomiasis in African children, and that such anaemia shows a significant improvement following chemotherapy. Results from the SCI study in Burkina Faso suggested that even a single round of mass chemotherapy can have a substantial impact on S. haematobium infection and its associated morbidity in children. Microscopy and haematuria dipsticks were suggested as sensitive and specific indicators of prevalence of S. haematobium infection in Ghanaian adults. Furthermore, ultrasound global scores were demonstrated to be valuable markers in children for morbidity caused by S. haematobium infection, but ultrasonographic examination is not a reasonable substitute for microscopy or dipsticks for determining the prevalence of this infection. Significance: Finally, the key findings from all the studies presented, emphasizing how these relate to one another, are discussed.