Comparative hepatitis: Diseases caused by adult parasites or their distinct life cycle stages

Abstract

There are a variety of parasites — protozoans, cestodes, trematodes, nematodes or pentastomides — which reside in the liver or invade this organ and are responsible for inflammation resulting in hepatitis. Among the Protozoa Entamoeba histolytica is of high importance. In the cyst fluid of the liver abscess purulent components are visible, but also some amoeba, so-called magna forms. Furthermore the amastigote stages of Trypanosoma cruzi and Leishmania donovani — both are Protozoa which possess a kinetoplast — and the schizonts of Plasmodium spp., which are the causative pathogens of malaria, have to be mentioned as a putative cause of parasite-induced hepatitis. Among cestodes Echinococcus granulosus and E. multilocularis preferentially reside in the liver. Within the trematodes Schistosoma spp., Clonorchis sinensis, Opisthorchis viverrini, Dicrocoelium dendriticum and the juvenile stages of Fasciola hepatica have to be considered. Among the large group of human nematodes, only Capillaria hepatica, migrating nematode larvae (such as larva 2) and the adults of Ascaris lumbricoides, larvae of Strongyloides stercoralis, hookworms, Toxocara canis and microfilariae of different filariae play a role in inducing liver inflammation.