Schistosoma mansoni: assessment of morbidity before and after control

The literature on the assessment of morbidity due to Schistosoma mansoni in fection is updated. Imaging techniques such as ultrasonography, echodoppler cardiography, computerized tomography (CT scan) and magnetic resonance ima ging (MRI) introduced a new perspective, and expanded our knowledge on morb idity. Three well-defined syndromes caused by schistosomiasis mansoni have been described: the stage of invasion, acute schistosomiasis (Katayama feve r), and chronic schistosomiasis. Complications of the acute and chronic syn dromes have also been reported: pulmonary hypertension, neuroschistosomiasi s, association with Salmonella, association with Staphylococci, viral hepat itis B, glomerulonephritis. In most individuals with hepatosplenic schistos omiasis the spleen is increased in size. Hepatosplenic schistosomiasis can, however, occur without splenomegaly. The definition of hepatosplenic schis tosomiasis in endemic areas as the finding of S. mansoni eggs in the stools in an individual with hepatosplenomegaly is not satisfactory anymore. Many aspects of morbidity are expected to change after schistosomiasis control. Some are expected to change quickly (worm burden, Salmonella bacteremia, h epatosplenic schistosomiasis in children) whereas others shall remain for y ears (pulmonary hypertension, glomerulonephritis, neuroschistosomiasis). In testinal schistosomiasis in individuals with low worm burdens is very diffi cult to diagnose and therefore laborious to control. (C) 2000 Elsevier Scie nce B.V. All rights reserved.