Hepatosplenic schistosomiasis: a model for the study of portal hypertension

作者：Edna Strauss · 发表于：Annals of Hepatology · 年份：2002 · DOI：10.1016/s1665-2681(19)32186-6 · 被引用次数：42 · 研究领域：Parasites and Host Interactions、Liver Disease and Transplantation、Amoebic Infections and Treatments

Annals of hepatologySchistosomiasis is an endemic disease of tropical areas.In American countries as Brazil, Venezuela, Puerto Rico, Antilles and Suriname the worm that causes schitosomiasis is the schistosoma mansoni.According to the World Health Orzganization more than 600 million people live in risk areas and about 200 million are infected in 75 countries.1 The biological cicle of the worm corresponds to three phases: when human feces containing the eggs of the parasite fall in water, they rupture liberating the miracide.The intermediate cicle occurs in a snail of the gender biomphalaria.The parasite multiplies inside the snail and after 20 to 30 days gives origin to the cercariae, that spread in warm water of about 20 to 25 degrees Celsius.Free in the water the cercariae enter through the intact skin and mucosa, suffering modifications and achieving maturation in the portal system, where sexuated adult worms lay their eggs.From the portal system eggs can spread to tissues and organs, specially the liver and intestines.As eggs are elimianted with feces they may contaminate water, closing the cycle.Adults worms live in the portal system, where about 300 eggs per day are laid and about 2/3 of them carried to the liver.The typical egg has a characteristic lateral spine, useful for its diagnosis, not only in stools but also in the various tissues where the egg can be found (Figure 1).As various couples of adult worms can be found in the veins of the portal system, specially th...