ORGANOMETRIC INVESTIGATIONS OF THE SPLEEN AND LIVER BY ULTRASOUND IN SCHISTOSOMA-MANSONI ENDEMIC AND NONENDEMIC VILLAGES IN SENEGAL

With the intention of ultrasonographically assessing hepatosplenic mor bidity in Schistosoma mansoni infection and of validating the grading system applied (Cairo classification), 191 subjects in a schistosomias is endemic village and 247 controls from a nonendemic village in north ern Senegal underwent sonographic examination of the liver and spleen. Measurements of the diameters of the peripheral periportal vein branc hes, the main portal vein stem, liver size (left lobe and right lobe), and spleen length in the endemic village were compared with those in the nonendemic village to evaluate the much discussed influence of S. mansoni infection on those variables. To subtract this presumed influe nce from reference values for the named variables, they are given as m easured in the nonendemic village, stratified by body weight, enabling future investigators on schistosomiasis-induced morbidity to refer to these reference values. The 95th percentile regarding peripheral peri portal vein branch diameter in the control groups was exceeded in 24% of the subjects in the endemic group. It was exceeded by 6% for the ma in portal vein stem diameter, 13% for the left Liver lobe, 12% for the right liver lobe, and 14% for the spleen length. According to the Cai ro classification, 97% of the endemic population and 81% of the contro ls had periportal thickening of the Liver, mostly grade I. We conclude that 1) hepatic morbidity in the S. mansoni endemic area was low, des pite strikingly high intensities of infection; 2) the Cairo classifica tion in its present form overestimates periportal thickening, especial ly in the case of mild morbidity; and 3) body height-dependent referen ce values, obtained from endemic controls, must be applied for organom etric parameters.