Liver abscess Parasitic liver abscess A liver abscess or cystic hepatic lesion caused by parasitic infection, with principal causative organisms being Entamoeba histolytica (amoebic liver abscess) and Echinococcus species (hepatic hydatid disease). Susceptibility to parasitic liver abscesses (e.g., amebic or hydatid) is primarily determined by environmental exposure and geographic endemicity rather than an underlying immune defect. While severe or atypical cases can occur in immunocompromised states, they are not standard diagnostic markers for primary immunodeficiency.