[History of a hepatic lesion: Schistosoma mansoni bilharziasis].

Schistosomiasis mansoni is a widespread tropical disease affecting about 200 million people in the world (data from the World Health Organization). The adult worms, settled in the mesenteric venous plexus, can survive in the host during 5 to 20 years. They evade the immune response and are not, by themselves, the main cause of the pathological events. Most eggs are swept into the portal circulation and trapped in different systemic organs, including the liver. The continuous egg deposition results in a T cell-mediated granulomatous response that is responsible for the disease syndrome (chronic hepatitis associated with a dense fibrosis and a concurrent portal hypertension). Current immunological and molecular concepts on the modulation of the granuloma, and the associated fibrosis, lead to a better understanding of the pathogenesis of human schistosomiasis. Chemotherapy with praziquantel is presently the main approach of morbidity control, before using in conjunction a human vaccine still in development.