PERIPORTAL FIBROSIS IN SCHISTOSOMA-MANSON I INFECTION - AN ULTRASONOGRAPHIC STUDY IN ADULT CAMEROONIAN PATIENTS

PURPOSE The appearance of Symmers' periportal fibrosis (SPF) is consid ered a major event in the natural history of Schistosoma mansoni infec tion, because of the risk of portal hypertension and subsequent intest inal hemorrhage. Ultrasonography has been found useful in the assessme nt of this lesion. We undertook the present study to determine the pre valence of SPF in Nkolbisson (near Yaounde), where previous studies ha d shown Schistosoma mansoni infection to be endemic. METHODS AND MATER IALS 147 patients more than 15 years old (mean age : 32 years) were pr ospectively studied during a 3 month period. 107 subjects (51 male, an d 56 female) were excreting Schistosoma mansoni eggs in the stools (me an egg output = 336 egg/g), and 40 controls had a negative stool exam. A medical history, a physical examination, and an abdominal ultrasoun d examination were performed on each subject. The degree of SPF was gr aded according to Homeida's scale. RESULTS 39 Subjects (24 male, 15 fe male) with positive stool examination had SPF giving a prevalence rate of 37%, while it was found to be 5% for controls. 28 patients had mil d fibrosis (grade 1), 7 patients had moderate fibrosis (grade 11), and 4 patients had severe fibrosis (grade III). Higher prevalence rates o f SPF were associated with longer duration of infection and very high egg outputs (>1,000 egg/g). The positive predictive value of hepatomeg aly or splenomegaly for the presence of SPF was 0.52, and the negative predictive value 0.69. CONCLUSION We conclude that SPF affects a sign ificant proportion of infected patients and ultrasonography is a valua ble tool in the study of this lesion in our patients.