Morbidity markers for Schistosoma haematobium infection.

A description is given of a field study design, including pretreatment and short and long-term posttreatment measurements, which is conducted as a case-control study among school children in Kaloleni District, Kenya, and Kilosa District, Tanzania, including 500 school children from each endemic setting. The aim of the study is to evaluate eosinophil cationic protein (ECP) in urine as a marker for Schistosoma haematobium morbidity by comparing levels of ECP in urine with S. haematobium egg counts in urine, level of excreted S. haematobium egg antigen in urine, microhaematuria and urinary tract pathology assessed by ultrasonography. Initial results have been promising and are now subject to an extensive evaluation. Strong training components and transfer of technology are included in the project, thus contributing to the strengthening of the research capacity of the collaborating African institutions. Simple non-invasive assays for ECP and excreted S. haematobium egg antigen could provide new tools for evaluation of chemotherapy effects and morbidity in urinary schistosomiasis, helping to understand the dynamic process of posttreatment resolution and reappearance of pathological changes.