Urinary schistosomiasis: a 5-year clinical, radiological, and functional evaluation

A review of the literature on the use of ultrasonography in schistosomiasis with special reference to its use in field studies

This review presents an outline of the pathology resulting from Schistosoma haematobium infections, and the ways in which the lesions can be investigated. The use of ultrasonography is covered in detail. Ultrasonography can provide direct information about lesions in internal organs, and thus provide information about patterns of morbidity and about the regression of pathological changes after treatment. The method has the advantages that it is non-invasive, and is also relatively inexpensive and can be used under field conditions. Ultrasonography has already been used in a number of epidemiological studies in areas where S. haematobium is endemic. The method has proved to be feasible and useful. However, the methodology used for ultrasound studies has varied considerably, so that it is difficult to make valid comparisons between results obtained in different places or at different times. A standardized methodology for making observations and recording the results is needed if the full potential benefit of using ultrasound in the monitoring of schistosomiasis control projects is to be realised. The correlation of results obtained using ultrasound with the results of clinical, parasitological and other observations has been investigated in a number of studies, but many questions remain to be answered.

Schistosoma haematobium egg counts in a Nile delta community

A study of Schistosoma haematobium egg counts was made in a community near Alexandria. This showed that the intensity of infection was similar to that which has been reported in some of the comparable surveys which have been made in sub-Saharan Africa. This finding highlights the need for further studies in defined communities of the pathogenicity of the infection. The egg counts of subjects who recalled treatment with tartar emetic within the last two years were similar to those who said they had never been treated. This suggests that the cost effectiveness of chemotherapeutic methods needs further evaluation.

Calcification of Schistosoma haematobium eggs: relation of radiologically demonstrable calcification to eggs in tissues and passage of eggs in urine

The extent of calcification of the bladder in schistosome infected patients is roughly correlated with the number of calcified schistosome eggs present in the bladder. The focal concentration of eggs in the bladder appears to be one major variable, and we estimate that as few as 100,000 eggs per cm2 might be detected in a clinical radiograph. The excretion of calcified eggs in the urine was related to the activity of the schistosome infection and was unaffected by the presence or extent of bladder calcification.